0

AIPMT 2005 (Biology)

Attempted 0/100 Correct 0 Score 0

Parkinson’s disease is caused by degeneration of brain neurons that are involved in movement control by making use of the neurotransmitter

  1. norepinephrine

  2. acetylcholine

  3. GABA

  4. dopamine


Correct Option: D
Explanation:

 Parkinson’s disease is caused by degeneration of brain neurons that are involved in movement control by making use of the neurotransmitter dopamine.

A women with 47 chromosomes due to three copies of chromosome 21 is characterized by

  1. Turner syndrome

  2. Down syndrome

  3. Superfemaleness

  4. Triploidy


Correct Option: B
Explanation:

 Down syndrome is a chromosomal abnormality characterized by the presence of an extra copy of genetic material on the 21st chromosome, either in whole (trisomy 21) or part (such as due to translocations). The effects of the extra copy varies greatly from individual to individual, depending on the extent of the extra copy, genetic background, environmental factors, and random chance.

Centromere is required for

  1. movement of chromosomes toward poles

  2. cytoplasmic cleavage

  3. crossing over

  4. transcription


Correct Option: A
Explanation:

  Centromeres appear as a constriction. They have a role in the separation of chromosomes into daughter cells during cell division (mitosis and meiosis).So,centromere is required for movement of chromosomes toward poles 

Protein synthesis in an animal cell occurs

  1. in ribosomes present in cytoplasm as well as in mitochondria

  2. in ribosomes present in the nucleolus as well as in cytoplasm

  3. only in ribosomes attached to the nuclear envelope and endoplasmic reticulum

  4. only in the ribosomes present in cytosol


Correct Option: A
Explanation:

 Protein synthesis in an animal cell occurs in ribosomes present in cytoplasm as well as in mitochondria.

Which of the following hydrolyses internal phosphodiester bonds in a polynucleotide chain?

  1. Lipase

  2. Protease

  3. Exonuclease

  4. Endonuclease


Correct Option: D
Explanation:

Endonuclease hydrolyses internal phosphodiester bonds in a polynucleotide chain. Restriction endonucleases (restriction enzymes) are divided into three categories: Type I, Type II, and Type III

Which one of the following phenomena supports Darwin's concept of natural selection in organic evolution?

  1. Production of 'Dolly', the sheep by cloning.

  2. Development of organs from 'stem cells' for organ transplantation.

  3. Development of transgenic animals

  4. Prevalence of pesticide resistant insects.


Correct Option: D
Explanation:

 Prevalence of pesticide resistant insects supports Darwin's concept of natural selection in organic evolution.Natural selection is the preservation of a functional advantage that enables a species to compete better in the wild. Natural selection is the naturalistic equivalent to domestic breeding.

Carbohydrates, the most abundant biomolecules on Earth, are produced by

  1. some bacteria, algae and green plant cells

  2. all bacteria, fungi and algae

  3. fungi, algae and green plant cells

  4. viruses, fungi and bacteria


Correct Option: A
Explanation:

 Carbohydrates, the most abundant biomolecules on Earth, are produced by some bacteria, algae and green plant cells.

According to widely accepted “fluid mosaic model” cell membranes are semi–fluid, where lipids and integral proteins can diffuse randomly. In recent years, this model has been modified in several respects. In this regard, which of the following statements is incorrect?

  1. Proteins can also undergo flip–flop movements in the lipid bilayer.

  2. Many proteins remain completely embedded within the lipid bilayer.

  3. Proteins in cell membranes can travel within the lipid bilayer.

  4. Proteins can remain confined within certain domains of the membrane.


Correct Option: A
Explanation:

 Most large proteins do not flip-flop due to their extensive polar regions, which are unfavorable in the hydrophobic core of a membrane bilayer. This allows the asymmetry of membranes to be retained for long periods, which is an important aspect of cell regulation.

At what stage of the cell cycle are histone proteins synthesized in a eukaryotic cell?

  1. During telophase

  2. During S–phase

  3. During G–2 stage of interphase

  4. During entire prophase


Correct Option: C
Explanation:

 G2 phase is a period of rapid cell growth and protein synthesis during which the cell readies itself for mitosis. So, during G–2 stage of interphase histone proteins synthesized in a eukaryotic cell.

The main organelle involved in modification and routing of newly synthesized proteins to their destinations is

  1. endoplasmic reticulum

  2. lysosome

  3. mitochondria

  4. chloroplast


Correct Option: A
Explanation:

 The main organelle involved in modification and routing of newly synthesized proteins to their destinations is endoplasmic reticulum.The endoplasmic reticulum serves many general functions, including the folding of protein molecules in sacs called cisternae and the transport of synthesized proteins in vesicles to the Golgi apparatus.

E.coli cells with a mutated z gene of the lac operon cannot grow in medium containing only lactose as the source of the energy because

  1. they cannot synthesise functional betagalactosidase

  2. they cannot transport lactose from the medium into the cell

  3. the lac operon is constitutively active in these cells

  4. in the presence of glucose, E.coli cells do not utilize lactose


Correct Option: A
Explanation:

 E.coli cells with a mutated z gene of the lac operon cannot grow in medium containing only lactose as the source of the energy because they cannot synthesise functional betagalactosidase.

Through which cell of the embryo sac does the pollen tube enter the embryo sac?

  1. Persistent synergid

  2. Egg cell

  3. Central cell

  4. Degenerated synergid


Correct Option: D
Explanation:

 Synergid cells are two specialized cells that lie adjacent to the egg cell in the female gametophyte of angiosperms and play an essential role in pollen tube guidance and function.

Which of the following unicellular organisms has a macronucleus for trophic function and one or more micronuclei for reproduction?

  1. Trypanosoma

  2. Paramecium

  3. Euglena

  4. Amoeba


Correct Option: B
Explanation:

The macronucleus controls non-reproductive cell functions, expressing the genes needed for daily functioning. The micronucleus is the generative or germline nucleus, containing the genetic material that is passed along from one generation to the next.

In contrast to Annelids the Platyhelminths show

  1. absence of body cavity

  2. presence of pseudocoel

  3. radial symmetry

  4. bilateral symmetry


Correct Option: A
Explanation:

 In contrast to Annelids the Platyhelminths show absence of body cavity. They are acoelomates (having no body cavity), and have no specialized circulatory and respiratory organs, which restricts them to having flattened shapes that allow oxygen and nutrients to pass through their bodies by diffusion.

Barophilic prokaryotes

  1. grow slowly in highly alkaline frozen lakes at high altitudes

  2. grow and multiply in very deep marine sediments

  3. readily grow and divide in sea water enriched in any soluble salt of barium

  4. occur in water containing high concentration of barium hydroxide


Correct Option: A
Explanation:

 Barophilic prokaryotes grow slowly in highly alkaline frozen lakes at high altitudes.They are also known as Piezophiles.

From the following statements, select the wrong one.

  1. Prawn has two pairs of antennae.

  2. Millepedes have two pairs of appendages in each segment of the body.

  3. Animals belonging to Phylum Porifera are exclusively marine.

  4. Nematocysts are characteristic of the phylum cnidaria.


Correct Option: C
Explanation:

  Animals belonging to Phylum Porifera are exclusively marine.This statement is wrong one as There is, however, one family of fresh water sponges (Family Spongillidae). 

There exists a close association between the alga and the fungus within a lichen. The fungus

  1. provides food for the alga

  2. provides protection, anchorage and absorption for the alga

  3. fixes the atmospheric nitrogen for the alga

  4. releases oxygen for the alga


Correct Option: B
Explanation:

 There exists a close association between the alga and the fungus within a lichen. The fungus provides protection, anchorage and absorption for the alga.This association is known as symbiosis.

Which of the following statements regarding enzyme inhibition is correct?

  1. Competitive inhibition is seen when a substrate competes with an enzyme for binding to an inhibitor protein.

  2. Competitive inhibitors often bind to the enzyme irreversibly.

  3. Competitive inhibition is seen when the substrate and the inhibitor compete for the active site on the enzymes.

  4. Non-competitive inhibition of an enzyme can be overcome by adding large amount of substrate.


Correct Option: C
Explanation:

 Competitive inhibition is seen when the substrate and the inhibitor compete for the active site on the enzymes. Most competitive inhibitors function by binding reversibly to the active site of the enzyme. As a result, many sources state that this is the defining feature of competitive inhibitors.

The ability of the Venus Flytrap to capture insects is due to

  1. rapid turgor pressure changes

  2. a passive process requiring no special ability on the part of the plant

  3. specialized “muscle-like” cells

  4. chemical stimulation by the pery


Correct Option: A
Explanation:

  The ability of the Venus Flytrap to capture insects is due to rapid turgor pressure changes.Each side of the trap has three to four sensor hairs, each no longer than 0.2 inches (0.5 centimeters). An insect must trip a hair twice or two hairs within 20 seconds for the trap to respond; this allows it to avoid snapping shut on raindrops or other false alarms. 

Golden rice is a transgenic crop of the future with the improved trait of

  1. high protein content

  2. high vitamin A content

  3. high lysine (essential amino acid) content

  4. insect resistance


Correct Option: B
Explanation:

 Golden rice is a transgenic crop of the future with the improved trait of high vitamin A content. Golden rice differs from its parental strain by the addition of three beta-carotene biosynthesis genes. The rice plant can naturally produce beta-carotene in its leaves, where it is involved in photosynthesis. However, the plant does not normally produce the pigment in the endosperm, where photosynthesis does not occur.

Which one of the following pairs is mis-matched?

  1. Nuclear power : radioactive wastes

  2. Solar energy : greenhouse effect

  3. Fossil fuel burning : release of CO2

  4. Biomass burning : release of CO2


Correct Option: B
Explanation:

 Solar energy : greenhouse effect This is a mis-matched pair.Solar energy is radiant light and heat from the Sun harnessed using a range of ever-evolving technologies such as solar heating, photovoltaics, solar thermal energy, solar architecture and artificial photosynthesis.

In a type of apomixes known as adventive embryony, embryos develop directly from the

  1. synergids or antipodals in an embryo sac

  2. nucellus or integuments

  3. zygote

  4. accessory embryo sacs in the ovule


Correct Option: B
Explanation:

 In adventitious embryony (sporophytic apomixis), an embryo is formed directly (not from a gametophyte) from nucellus or integument tissue.Adventive embryony is important in several species of Citrus, in Garcinia, Euphorbia dulcis, Mangifera indica etc.

Using imprints from a plate with complete medium and carrying bacterial colonies, you can select streptomycin resistant mutants and prove that such mutations do not originate as adaptation. These imprints need to be used

  1. on plates with and without streptomycin

  2. only on plates with streptomycin

  3. on plates with minimal medium

  4. only on plates without streptomycin


Correct Option: B
Explanation:

 To check resistance of mutants against streptomycin they must be grown on plates with streptomycin. Only those bacterial colonies will propagate from the master that are resistant to the antibiotic.

Identify the correctly matched pair.

  1. Kyoto Protocol : Climatic change

  2. Montreal Protocol : Global warming

  3. Basal Convention : Biodiversity conservation

  4. Ramsar Convention : Ground water pollution


Correct Option: A
Explanation:

 Kyoto Protocol : Climatic change This is the correct option among the all options provided. Montreal Protocol was on Substances that Deplete the Ozone Layer. The Basel Convention was on the Control of Transboundary Movements of Hazardous Wastes and Their Disposal. The Ramsar Convention was Convention on Wetlands of International Importance, especially as Waterfowl Habitat.

Which of the following is generally used for induced mutagenesis in crop plants?

  1. Gamma–rays (from Cobalt 60)

  2. Alpha – particles

  3. X–rays

  4. UV (260 nm)


Correct Option: A
Explanation:

 Gamma–rays (from Cobalt 60) generally used for induced mutagenesis in crop plants. They were employed to develop 64% of the radiation-induced mutant varieties, followed by X-rays (22%).

Auxospores and hormocysts are formed, respectively, by

  1. some cyanobacteria and many diatoms

  2. several diatoms and a few cyanobacteria

  3. several cyanobacteria and several diatoms

  4. some diatoms and several cyanobacteria


Correct Option: B
Explanation:

 Auxospores and hormocysts are form, respectively, by several diatoms and a few cyanobacteria. Auxospores typically play a role in growth processes, sexual reproduction or dormancy in some species of diatoms. Hormocysts are the specialised structures found in cyanobacteria which help in reproduction.

One of the most important functions of botanial gardens is that

  1. they allow ex-situ conservation of germless

  2. they provide the natural habitat for wildllil

  3. one can observe tropical plants there.

  4. they provide a beautiful area for recreatia


Correct Option: A

More than 70% of world's freshwater is contained in

  1. Antarctica.

  2. Polar ice.

  3. Glaciers and Mountains.

  4. Greenland.


Correct Option: B
Explanation:

 A polar ice cap or polar cap is a high-latitude region of a planet, dwarf planet, or natural satellite that is covered in ice.Around 70% of the fresh water on Earth is contained in this ice sheet.

Match List I with List II and select the correct answer using the codes given below the Lists: List I List II I. Peritrichous flagellation (A) Ginkgo II. Living fossil (B) Macrocystes III. Rhizophore (C) Escherichia coli IV. Smallest flowering plant (D) Selaginella V. Largest perennial alga (E) Wolffia

  1. I - C, II - A, III - D, IV - E, V - B

  2. I - B, II - A, III - C, IV - D, V - E

  3. I - A, II - B, III - E, IV - C, V - B

  4. I - E, II - C, III - B, IV - E, V - A


Correct Option: A
Explanation:

 I - C, II - A, III - D, IV - E, V - B I. Peritrichous flagellation      (C) Escherichia coli II. Living fossil                          (A) Ginkgo III. Rhizophore                         (D) Selaginella IV. Smallest flowering plant (E) Wolffia V. Largest perennial alga     (B) Macrocystes

Animals have the innate ability to escape from predation. Examples for the same are given below. Select the incorrect example.

  1. Colour change in chameleon.

  2. Poison fangs in snakes.

  3. Melanism in moths.

  4. Enlargement of body size by swallowing air in puffer fish.


Correct Option: D
Explanation:

 Enlargement of body size by swallowing air in puffer fish.This statement is wrong. All the other options help in deception from predation.

AIDS is caused by HIV that principally infects

  1. activator B cells.

  2. T4 lymphocytes.

  3. cytotoxic T cells.

  4. all lymphocytes.


Correct Option: B
Explanation:

 HIV infection is associated with the progressive loss of CD4(+) T cells through their destruction or decreased production.

The world's highly prized wool yielding 'Pashmina' breed is

  1. Kashmir sheep - Afghan sheep cross.

  2. goat.

  3. sheep.

  4. goat-sheep cross.


Correct Option: B
Explanation:

 The world's highly prized wool yielding 'Pashmina' breed is goat. The goat  most known for its fine cashmere is Himalayan goats, often referred to as Cashmere goats. The name Cashmere derives from the Indian region Kashmir, where the first Cashmere clothing was appreciated. Another very well known word for Cashmere is Pashmina. This derives from the Persian word for "wool".

Why is vivipary an undesirable character for annual crop plants?

  1. It reduces the vigour of the plant.

  2. The seeds exhibit long dormancy.

  3. It adversely affects the fertility of the plant.

  4. The seeds cannot be stored under normal conditions for the next season.


Correct Option: D
Explanation:

 Vivipary is the condition whereby the embryo (the young plant within the seed) grows first to break through the seed coat then out of the fruit wall while still attached to the parent plant. It is an undesirable character for annual crop plants as the seeds cannot be stored under normal conditions for the next season.

An important step in the manufacture of pulp for paper industry from the woody tissues of plants is the

  1. removal of water from the wood by prolonged heating at approximately 50oC.

  2. treatment of wood with chemical that breaks down cellulose.

  3. removal of oils present in the wood by treatment with suitable chemicals.

  4. preparation of pure cellulose by removing lignin.


Correct Option: D
Explanation:

 An important step in the manufacture of pulp for paper industry from the woody tissues of plants is the preparation of pure cellulose by removing lignin.

For retting of jute, the fermenting microbe used is

  1. Methophilic bacteria

  2. Helicobactor pylori

  3. Butyric acid bacteria

  4. Streptococcus lacin


Correct Option: C
Explanation:

 Butyric acid producing anerobic bacteria is used for retting of jute. Retting is a process employing the action of microorganisms and moisture on plants to dissolve or rot away much of the cellular tissues and pectins surrounding bast-fibre bundles, and so facilitating separation of the fibre from the stem.

Three crops that contribute maximum to global foodgrain production are

  1. wheat, rice and maize.

  2. rice, maize and sorghum.

  3. wheat, maize and sorghum.

  4. wheat, rice and barley.


Correct Option: A
Explanation:

 Three crops that contribute maximum to global foodgrain production are wheat, rice and maize. They are grown maximally as they form one of the staple diets of largest population of the world.

During which stage in the complete oxidation of glucose are the greatest number of ATP molecules formed from ADP?

  1. Glycolysis

  2. Krebs cycle

  3. Electron transport chain

  4. Conversion of pyruvic acid to acetyl CoA.


Correct Option: C
Explanation:

 An electron transport chain (ETC) is a series of compounds that transfer electrons from electron donors to electron acceptors via redox reactions, and couples this electron transfer with the transfer of protons (H+ ions) across a membrane. This creates an electrochemical proton gradient that drives the synthesis of adenosine triphosphate (ATP), a molecule that stores energy chemically in the form of highly strained bonds. In most organisms the majority of ATP is generated in electron transport chains.

At which latitude, heat gain through insolation approximately equals heat loss through terrestrial radiation?

  1. 42 ½o North and South

  2. 22 ½o North and South

  3. 40o North and South

  4. 66o North and South


Correct Option: B
Explanation:

  At 22 ½o North and South Latitude heat gain through insulation approximately equals heat loss through terrestrial radiation.

Which of the following represents the edible part of fruit 'Litchi'?

  1. Endocarp

  2. Pericarp

  3. Juicy aril

  4. Mesocarp


Correct Option: C
Explanation:

 The edible white aril of Litchi chinensis is sometimes called an arillode. It grows partly from the funiculus and partly from the integument of the seed.

Ectophloic siphonostele is found in

  1. Osminda and Equisetum

  2. Adiantum and Cucurbitaceae

  3. Marsilea and Botrychiun

  4. Dicksonia and Maidenhair fern


Correct Option: C
Explanation:

 Ectophloic siphonostele is a type of stele with pith that has the phloem only on the outside of the xylem. It is found in Marsilea and Botrychiun.

The deficiencies of micronutrients, not only affects growth of plants but also vital functions such as photosynthetic and mitochondrial electron flow. Among the list given below, which group of three elements shall affect most, both photosynthetic and mitochondrial electron transport?

  1. Ca, K, Na

  2. Co, Ni, Mo

  3. Mn, Co, Ca

  4. Cu, Mn, Fe


Correct Option: C
Explanation:

 Mn, Co, Ca these three elements affect both photosynthetic and mitochondrial electron transport.They are activally involved in both the processes.

Biodiversity Act of India was passed by the Parliament in the year

  1. 2002

  2. 1992

  3. 1996

  4. 2000


Correct Option: A
Explanation:

 The Biological Diversity Act, 2002 is an Act of the Parliament of India for preservation of biological diversity in India, and provides mechanism for equitable sharing of benefits arising out use of traditional biological resources and knowledge. The Act was enacted to meet the obligations under Convention on Biological Diversity (CBD), to which India is a party.

Which of the following is not used for disinfection of drinking water?

  1. Chlorine

  2. Phenyl

  3. Chloramine

  4. Ozone


Correct Option: B
Explanation:

  Phenyl is not used for disinfection of drinking water.Chlorine, chloramine and ozone are mainly used for disinfection of the water.

As compared to a C3- plant, how many additional molecules of ATP are needed for net production of one molecule of hexose sugar by C4- plants?

  1. Zero

  2. Six

  3. Two

  4. Twelve


Correct Option: D
Explanation:

 As compared to a C3- plant, twelve additional molecules of ATP are needed for net production of one molecule of hexose sugar by C4- plants. 18 ATPs are required to synthesize one glucose molecule in C3 plant and 30 ATPs are required to synthesize one glucose molecule in C4 plants.

The salivary gland chromosomes in the diptera larvae, are useful in gene mapping because

  1. they have endoreduplicated chromosomes

  2. these are fused.

  3. these are easy to stain.

  4. these are much longer in size.


Correct Option: A
Explanation:

  Polytene Chromosomes (Salivary Chromosomes) were discovered by Balbiani (1881) in the salivary glands of Chironomus tantans. Later they were found in salivary glands of many insect larvae including Drosophila. Polytene chromosomes are formed by somatic pairing of homologous chromosomes followed by their repeated replication or endomitosis. They are in permanent prophase.

Prolonged liberal irrigation of agricultural fields is likely to create the problem of

  1. aridity.

  2. metal toxicity.

  3. salinity.

  4. acidity.


Correct Option: C
Explanation:

 Salinity from irrigation can occur over time wherever irrigation occurs, since almost all water (even natural rainfall) contains some dissolved salts. When the plants use the water, the salts are left behind in the soil and eventually begin to accumulate. Since soil salinity makes it more difficult for plants to absorb soil moisture, these salts must be leached out of the plant root zone by applying additional water.

Chemiosmotic theory of ATP synthesis in the chloroplasts and mitochondria is based on

  1. membrane potential.

  2. accumulation of K ions.

  3. proton gradient.

  4. accumulation of Na ions.


Correct Option: C
Explanation:

 Chemiosmotic theory of ATP synthesis in the chloroplasts and mitochondria is based on proton gradient.Chemiosmosis is the movement of ions across a selectively permeable membrane, down their electrochemical gradient. More specifically, it relates to the generation of ATP by the movement of hydrogen ions across a membrane during cellular respiration or photosynthesis.

In a woody dicotyledonous tree, which of the following parts will mainly consist of primary tissues?

  1. Stem and root.

  2. All parts

  3. Shoot tips and root tips

  4. Flowers, fruits and leaves


Correct Option: D
Explanation:

 In a woody dicotyledonous tree,primary growth is tissue is present in Flowers, fruits and leaves because these are the active sites of growth.

On which principle does a potometer work?

  1. Potential difference between the tip of the tube and that of the plant

  2. Amount of water absorbed equals the amount transpired

  3. Osmotic pressure

  4. Root pressure


Correct Option: B
Explanation:

 Potometer works on the principle that amount of water absorbed equals the amount transpired. There are two main types of potometers used - the bubble potometer and the mass potometer.

Chlorophyll in chloroplasts is located in

  1. grana.

  2. prenoid.

  3. stroma.

  4. both grana and stroma.


Correct Option: A
Explanation:

 A granum (plural grana) is a stack of thylakoid discs.A thylakoid is a membrane-bound compartment inside chloroplasts.They are the site of the light-dependent reactions of photosynthesis. Pyrenoids are sub-cellular micro-compartments found in chloroplasts of many algaeThe stroma of a plant is the region outside of the thylakoid space; most of the enzymes essential in the process of photosynthesis are generally embedded in the stroma and in the thylakoid membranes.

Photosynthesis in C4- plants is relatively less limited by atmospheric CO2 levels because

  1. the primary fixation of CO2 is mediated via PEP carboxylase.

  2. effective pumping of CO2 into bundlesheath cells.

  3. four carbon acids are the primary initial CO2 fixation products.

  4. rubisco in C4- plants has higher affinity for CO2.


Correct Option: A
Explanation:

 Photosynthesis in C4- plants is relatively less limited by atmospheric CO2 levels because the primary fixation of CO2 is mediated via PEP carboxylase.

Photosynthetic Active Radiation (PAR) has the following range of wavelengths

  1. 340 - 450 nm.

  2. 450 - 950 nm.

  3. 500 - 600 nm.

  4. 400 - 700 nm.


Correct Option: D
Explanation:

 Photosynthetically active radiation( PAR), designates the spectral range (wave band) of solar radiation from 400 to 700 nanometers that photosynthetic organisms are able to use in the process of photosynthesis. This spectral region corresponds more or less with the range of light visible to the human eye. Photons at shorter wavelengths tend to be so energetic that they can be damaging to cells and tissues, but are mostly filtered out by the ozone layer in the stratosphere. Photons at longer wavelengths do not carry enough energy to allow photosynthesis to take place.

Enzymes, vitamins and hormones can be classified into a single category of biological chemicals because all of these

  1. are exclusively synthesised in the body of a living organism

  2. enhance oxidative metabolism

  3. are conjugated proteins

  4. help in regulating metabolism


Correct Option: D
Explanation:

Enzymes, vitamins and hormones can be classified into a single category of biological chemicals because all of these help in regulating metabolism.

G - 6 - P dehydrogenase deficiency is associated with haemolysis of

  1. Leucocytes.

  2. Lymphocytes.

  3. Platelets.

  4. RBCs.


Correct Option: D
Explanation:

 Glucose-6-phosphate dehydrogenase deficiency is a genetic disorder that occurs most often in males. This condition mainly affects red blood cells, which carry oxygen from the lungs to tissues throughout the body. In affected individuals, a defect in an enzyme called glucose-6-phosphate dehydrogenase causes red blood cells to break down prematurely. This destruction of red blood cells is called hemolysis.

An acromian process is characteristically found in the

  1. skull of frog.

  2. sperm of mammals.

  3. pelvic gridle of mammals.

  4. pectoral girdle of mammals.


Correct Option: D
Explanation:

 An acromion process is a type of bony process which articulates with the clavicle, or collar bone. It is characteristically found in the pectoral girdle of mammals.

In ornithine cycle, which of the following wastes are removed from the blood?

  1. CO2 and ammonia

  2. Ammonia and urea

  3. CO2 and urea

  4. Urea and urine


Correct Option: A
Explanation:

 In ornithine cycle, CO2 and ammonia wastes are removed from the blood. In mammals, this cycle takes place primarily in the liver, and to a lesser extent in the kidney.

Secretin and cholecystokinin are digestive hormones. They are secreted in

  1. oesophagus.

  2. ileum.

  3. duodenum.

  4. pyloric stomach.


Correct Option: C
Explanation:

 Secretin and cholecystokinin are digestive hormones. They are secreted in duodenum when acidic food enters there. Secretin stimulates release of bicarbonate rich fluid from the pancreas to counteract the acid. CCK stimulates pancreatic enzyme section like amylase and lipase, which aid in breaking down food. It also causes contraction of the gallbladder, which releases bile into the duodenum.

Which of the following characters is/are not typical of class Mammalia?

  1. Alveloar lungs

  2. Ten pairs of cranial nerves

  3. Seven cervical vertebrae

  4. Thecodont dentition


Correct Option: B
Explanation:

 There are 12 pairs of cranial nerves in class Mammalia.

Grey crescent is the area

  1. at the point of entry of sperm into ovum.

  2. just opposite to the site of entry of sperm into ovum.

  3. at the animal pole.

  4. at the vegetal pole.


Correct Option: B
Explanation:

  Grey crescent is the area just opposite to the site of entry of sperm into ovum.Its establishment determines the location of the dorsal and ventral (up-down) axis, as well as of the anterior and posterior (front-back) axis and the dextro-sinistral (left-right) axis of the embryo.

Which one of the following pairs is mis–matched?

  1. Savanna : Acacia trees

  2. Coniferous forest : Evergreen trees

  3. Tundra : Permafrost

  4. Prairie : Epiphytes


Correct Option: D
Explanation:

Epiphytes are plants that live on other plants. They do not take nourishment from their host as parasitic plants do. As their roots do not reach the ground, they depend on the air to bring them moisture and inorganic nutrients. Many orchids and many bromeliads (members of the pineapple family like "Spanish moss") are epiphytes. Grasslands are also known as prairie or plains

The net pressure gradient that causes the fluid to filter out of the glomeruli into the capsule is

  1. 20 mm Hg.

  2. 50 mm Hg.

  3. 75 mm Hg.

  4. 30 mm Hg.


Correct Option: A
Explanation:

 The net pressure gradient that causes the fluid to filter out of the glomeruli into the capsule is 20 mm Hg. A glomerular hydrostatic pressure of 70 mm Hg develops in glomerulus. It is opposed by blood osmotic pressure (30 mm Hg) and capsular hydrostatic pressure (20 mm Hg ) inside the Bowman's capsule.

If mammalian ovum fails to get fertilized, which one of the following is unlikely?

  1. Estrogen secretion further decreases.

  2. Progesterone secretion rapidly declines.

  3. Corpus luteum will disintegrate.

  4. Primary follicle starts developing.


Correct Option: D
Explanation:

 From birth, the ovaries of the human female contain a number of immature, primordial follicles. These follicles each contain a similarly immature primary oocyte. After puberty and commencing with the first menstruation, a clutch of follicles begins folliculogenesis, entering a growth pattern that will end in death or in ovulation (the process where the oocyte leaves the follicle).

Top-shaped multiciliate male gametes, and the mature seed which bears only one embryo with two cotyledons, are characteristic features of

  1. Gamopetalous angiosperms.

  2. Conifers.

  3. Polypetalous angiosperms.

  4. Cycads.


Correct Option: D
Explanation:

 Top-shaped multiciliate male gametes, and the mature seed which bears only one embryo with two cotyledons, are characteristic features of Cycads.In Cycas pollination is anemophilous (by wind). The 3-celled microspores liberate from mega-sporangia are blown away by wind. Finally microspores reach on ovules and get enlarged in the pollination drop (ooze) of micropyle. As the ooze dries up, the microspores are drawn into the pollen chamber.

Which of the following represents an ovule where the embryo sac becomes horseshoe-shaped and the funiculus and micropyle are close to each other?

  1. Amphitropous

  2. Antropous

  3. Circinotropous

  4. Atropous


Correct Option: A
Explanation:

 In amphitropous ovule, the embryo sac becomes horseshoe-shaped and the funiculus and micropyle are close to each other.

Epithelial cells of the intestine involved in food absorption have on their surface

  1. zymogen granules.

  2. pinocytic vesicles.

  3. phagocytic vesicles.

  4. microvilli.


Correct Option: D
Explanation:

  Epithelial cells of the intestine involved in food absorption have on microvilli on their surface. Microvilli effectively increase the surface area of the cell and are useful for absorption and secretion functions.

Which of the following substances, if introduced into the blood stream, would cause coagulation of blood at the site of its introduction?

  1. Thromboplastin

  2. Fibrinogen

  3. Heparin

  4. Prothrombin


Correct Option: A
Explanation:

 Thromboplastin is a plasma protein aiding blood coagulation through catalyzing the conversion of prothrombin to thrombin. So, if introduced into the blood stream, it would cause coagulation of blood at the site of its introduction.

One of the examples of the action of the autonomous nervous system is

  1. knee-jerk response.

  2. pupillary reflex.

  3. peristalisis of the intestines.

  4. swallowing of food.


Correct Option: C
Explanation:

 Autonomic nervous system is involved in peristalsis of intestine which is effected through mysentric plexus.Other options are examples of reflex actions.

Damage to thymus in a child may lead to

  1. a reduction in hameoglobin content of blood.

  2. a reduction in stem cell production.

  3. loss of antibody mediated immunity.

  4. loss of cell mediated immunity.


Correct Option: D
Explanation:

 Thymus gland is associated with production T-lymphocytes ,which are important part of our immune system. They get matured in thymus gland .So,damage to thymus in a child may lead to loss of cell mediated immunity.

In a man, abducens nerve is injured. Which of the following functions will be affected?

  1. Swallowing

  2. Movement of the eyeball

  3. Movement of the neck

  4. Movement of the tongue


Correct Option: B
Explanation:

In a man, if abducens nerve is injured, then movement of the eyeball is affected as it controls the movement of a single muscle, the lateral rectus muscle of the eye.

A patient is generally advised to specially consume more meat, lentils, milk and eggs in diet only when he suffers from

  1. Anaemia.

  2. Scurvy.

  3. Kwashiorkor.

  4. Rickets.


Correct Option: C
Explanation:

 Kwashiorkor is a form of severe protein–energy malnutrition.Sufficient calorie intake, but with insufficient protein consumption, distinguishes it from marasmus. Kwashiorkor cases occur in areas of famine or poor food supply.So a patient suffering from Kwashiorkor is generally advised to specially consume more meat, lentils, milk and eggs in diet.

Which of the following pairs, is correctly matched?

  1. Fibrous joint : Between phalanges

  2. Cartilaginous joint : Skull bones

  3. Gliding joint : Between zyga pophyses of the successive vertebrae

  4. Hinge joint : Between vertebrae


Correct Option: C
Explanation:

 Gliding joint is a type of joint allows for gliding movements between flat surfaces as the surfaces slide over one another. Only a limited amount of movement is allowed such as those between the articular processes (zygapophyses) of successive vertebrae. Fibrous joint is present between skull bones. Cartilaginous joint is present between vertebrae. Hinge joint is present between knee and elbow.

A person is undergoing prolonged fasting. His urine will be found to contain abnormal quantities of

  1. fats

  2. amino acids.

  3. ketones

  4. glucose.


Correct Option: C
Explanation:

  A person is undergoing prolonged fasting. His urine will be found to contain abnormal quantities of ketones. Ketones are metabolic end-products of fatty acid metabolism. In healthy individuals, ketones are formed in the liver and are completely metabolized so that only negligible amounts appear in the urine. However, when carbohydrates are unavailable or unable to be used as an energy source, fat becomes the predominant body fuel instead of carbohydrates and excessive amounts of ketones are formed as a metabolic byproduct. Higher levels of ketones in the urine indicate that the body is using fat as the major source of energy.

Which of the following is the simplest amino acid?

  1. Alanine

  2. Asparagine

  3. Glycine

  4. Tyrosine


Correct Option: C
Explanation:

The simplest and smallest amino acid found in proteins is glycine, for which the R-group is a hydrogen (H).

According to IUCN Red List, what is the status of Red Panda (Ailurus fulgens)?

  1. Critically endangered species

  2. Vulnerable species

  3. Extinct species

  4. Endangered species.


Correct Option: D
Explanation:

 An Endangered (EN) species is a species which has been categorized by the International Union for Conservation of Nature (IUCN) Red List as likely to become extinct. "Endangered" is the second most severe conservation status for wild populations in the IUCN's schema after Critically Endangered (CR). According to IUCN Red List of Red Panda (Ailurus fulgens) comes under Endangered species.

Which one of the following makes use of RNA as a template to synthesise DNA?

  1. DNA dependent RNA polymerase

  2. DNA polymerase

  3. Reverse transcriptase

  4. RNA polymerase.


Correct Option: C
Explanation:

 The synthesis of DNA from an RNA template, via reverse transcription, produces complementary DNA (cDNA). Reverse transcriptases (RTs) use an RNA template and a short primer complementary to the 3' end of the RNA to direct the synthesis of the first strand cDNA, which can be used directly as a template for the Polymerase Chain Reaction (PCR).

At a particular locus, frequency of ‘A’ allele is 0.6 and that of ‘a’ is 0.4. What would be the frequency of heterozygotes in a random mating population at equilibrium?

  1. 0.24

  2. 0.16

  3. 0.48

  4. 0.36


Correct Option: C
Explanation:

  The genotype proportions p2, 2pq, and q2 are called the Hardy-Weinberg proportions.Two alleles denoted A and a with frequencies f(A) = p and f(a) = q, respectively,Expected genotype frequencies are-  f(AA) = p2 for the AA homozygotes,  f(aa) = q2 for the aa homozygotes, and f(Aa) = 2pq for the heterozygotes. So, the frequency of heterozygotes = 2pq= 2 X 0.6 X 0.4 = 0.48 

Nucleotides are building blocks of nucleic acids. Each nucleotide is a composite molecule formed by

  1. base-sugar-OH

  2. base-sugar-phosphate

  3. sugar-phosphate

  4. (base-sugar-phosphate)n


Correct Option: B
Explanation:

 A nucleotide is one of the structural components or building blocks of DNA and RNA. A nucleotide consists of a base (one of four chemicals: adenine, thymine, guanine, and cytosine) plus a molecule of sugar and one of phosphoric acid.

A student wishes to study the cell structure under a light microscope having 10X eyepiece and 45X objective. He should illuminate the object by which one of the following colours of light so as to get the best possible resolution?

  1. Red

  2. Green

  3. Yellow

  4. Blue.


Correct Option: D
Explanation:

 Resolution of the microscope is inversely proportional to the wavelenth of the light used.The light with short wavelength have the higher resolution.Out of the given options, blue light have the minimum wavelength, hence have highest resolution.

In order to find out the different types of gametes produced by a pea plant having the genotype AaBb, it should be crossed to a plant with the genotype

  1. AaBb

  2. aabb

  3. AABB

  4. aaBB


Correct Option: B
Explanation:

 In order to find out the different types of gametes produced by a pea plant having the genotype AaBb, it should be crossed to a plant with the homozygous recessive genotype.It is called Test Cross.So, in above options, it should be crossed with aabb double recessive plant.

During transcription holoenzyme RNA polymerase binds to a DNA sequence and the DNA assumes a saddle like structure at that point. What is that sequence called?

  1. CA AT box

  2. GGT T box

  3. A A AT box

  4. TATA box


Correct Option: D
Explanation:

 During transcription holoenzyme RNA polymerase binds to a DNA sequence and the DNA assumes a saddle like structure at that point. This sequence is called TATA box. It is a type of promoter sequence, which specifies to other molecules where transcription begins.

A man and a woman, who do not show any apparent signs of a certain inherited disease, have seven children (2 daughters and 5 sons). Three of the sons suffer from the given disease but none of the daughters is affected. Which of the following mode of inheritance do you suggest for this disease?

  1. Sex-limited recessive

  2. Autosomal dominant

  3. Sex-linked recessive

  4. Sex-linked dominant.


Correct Option: C
Explanation:

 Sex-linked recessive traits typically occur only in males. Because the sex-linked trait is invariably X-linked, males transmit the trait only to their daughters, all of whom become carriers. Carrier (heterozygous) females can then transmit the trait to 50% of their male and female offspring. Affected males are hemizygous for the X-linked trait.

In which one pair both the plants can be vegetatively propagated by leaf pieces?

  1. Bryophyllum and Kalanchoe

  2. Agave and Kalanchoe

  3. Asparagus and Bryophyllum

  4. Chrysanthemum and Agave.


Correct Option: A
Explanation:

 Bryophyllum and Kalanchoe both the plants can be vegetatively propagated by leaf pieces.It is a type of asexual type of reproduction.

A woman with normal vision, but whose father was colour blind, marries a colour blind man. Suppose that the fourth child of this couple was a boy. This boy

  1. must have normal colour vision.

  2. may be colour blind or may be of normal vision.

  3. will be partially colour blind since he is heterozygous for the colour blind mutant allele.

  4. must be colour blind.


Correct Option: B
Explanation:

 A woman with normal vision, but whose father was colour blind, marries a colour blind man. Suppose that the fourth child of this couple was a boy. This boy may be colour blind or may be of normal vision.

Telomerase is an enzyme which is a

  1. RNA.

  2. ribonucleoprotein.

  3. repetitive DNA.

  4. simple protein.


Correct Option: B
Explanation:

 Telomerase, also called telomere terminal transferase,is a ribonucleoprotein that adds the polynucleotide "TTAGGG" to the 3' end of telomeres, which are found at the ends of eukaryotic chromosomes.

De Vries gave his mutation theory on organic evolution while working on

  1. Oenothera lamarckiana

  2. Drosophila melanogaster.

  3. Pisum sativum.

  4. Althea rosea


Correct Option: A
Explanation:

 In 1890 the Dutch geneticist Hugo de Vries discovered Oenothera lamarckiana or the evening primrose of Lamarck, growing as a parkland-escape on an abandoned field near Hilversum. In this plant de Vries believed he had found evidence that Charles Darwin was wrong.

Genes for cytoplasmic male sterility in plants are generally located in

  1. Nuclear genome.

  2. Chloroplast genome.

  3. Cytosol.

  4. Mitochondrial genome.


Correct Option: D
Explanation:

 Genes for cytoplasmic male sterility in plants are generally located in Mitochondrial genome. Mitochondrial DNA is only a small portion of the DNA in a eukaryotic cell; most of the DNA can be found in the cell nucleus and, in plants, in the chloroplast.

The name of Norman Borlaug is associated with

  1. Green Revolution.

  2. White Revolution.

  3. Yellow Revolution.

  4. Blue Revolution.


Correct Option: A
Explanation:

 Norman Ernest Borlaug was an American biologist, humanitarian and Nobel laureate who has been called "the father of the Green Revolution".He took up an agricultural research position in Mexico, where he developed semi-dwarf, high-yield, disease-resistant wheat varieties.

Which one of the following experiments suggests that simplest living organisms could not have originated spontaneously from non-living matter?

  1. Larvae could appear in decaying organic matter.

  2. Meat was not spoiled, when heated and kept sealed in a vessel.

  3. Microbes did not appear in stored meat.

  4. Microbes appeared from unsterilised organic matter.


Correct Option: B
Explanation:

  Meat was not spoiled, when heated and kept sealed in a vessel, This experiment suggests that simplest living organisms could not have originated spontaneously from non-living matter.This  experiment was showing evidence against theory of spontanous generation.

Which of the following is not a hereditary disease?

  1. Haemophilia

  2. Cretinism

  3. Cystic fibrosis

  4. Thalassaemia


Correct Option: B
Explanation:

 Cretinism is a condition of severely stunted physical and mental growth due to untreated congenital deficiency of thyroid hormones (congenital hypothyroidism) usually due to maternal hypothyroidism.

Which of the following is not true for a species?

  1. Members of a species can interbreed.

  2. Variations occur among members of a species.

  3. Gene flow does not occur between the populations of a species.

  4. Each species is reproductively isolated from every other species.


Correct Option: C
Explanation:

  Gene flow does occur between the populations of a species as they freely interbreed.so new genetic combinations occur.

Which of the following is the relatively most accurate method for dating of fossils?

  1. Electron-spin resonance method.

  2. Uranium-lead method.

  3. Potassium-argon method.

  4. Radio-carbon method.


Correct Option: C
Explanation:

 Potassium-argon method is the relatively most accurate method for dating of fossils.It is based on measurement of the product of the radioactive decay of an isotope of potassium (K) into argon (Ar). Potassium is a common element found in many materials, such as micas, clay minerals, tephra, and evaporites.

Haemophilia is more commonly seen in human males than in human females because

  1. this disease is due to a Y-linked recessive mutation.

  2. this disease is due to an X-linked recessive mutation.

  3. this disease is due to an X-linked dominant mutation.

  4. a greater proportion of girls die in infancy.


Correct Option: B
Explanation:

 Haemophilia is more commonly seen in human males than in human females because this disease is due to an X-linked recessive mutation.X-linked recessive inheritance is a mode of inheritance in which a mutation in a gene on the X chromosome causes the phenotype to be expressed in males (who are necessarily hemizygous for the gene mutation because they have one X and one Y chromosome) and in females who are homozygous for the gene mutation.

A person got injured in his twenties resulting in damage and death of a few cells of the following. Which of these cells are least likely to be replaced by new cells?

  1. Osteocytes

  2. Hepatocytes

  3. Neurons

  4. Neutrophils


Correct Option: C
Explanation:

 Neurons are least likely to regnerate when lost . They have least power of regeneration.

All of the following statements concerning the Actinomycetous filamentous soil bacterium Frankia are correct except that Frankia?

  1. forms specialized vesicles in which the nitrogenase is protected from oxygen by a chemical barrier involving triterpene hopanoids

  2. Can induce root nodules on many plant species.

  3. like Rhizobium, it usually infects its host plant through root hair deformation and stimulates cell proliferation in the host's cortex

  4. Can fix nitrogen in the free-living state.


Correct Option: D
Explanation:

  Frankia cannot fix nitrogen in the free-living state.Frankia is a nitrogen-fixing bacterium that lives in the soil and has a symbiotic relationship with many plants.

Bacillus thuringiensis (Bt) strains have been used for designing novel

  1. bio-insecticidal plants.

  2. bio-mineralization processes.

  3. bio-fertilizers.

  4. bio-metallurgical techniques.


Correct Option: A
Explanation:

  Bacillus thuringiensis (Bt) strains have been used for designing novel bio-insecticidal plants.During sporulation, many Bt strains produce crystal proteins (proteinaceous inclusions), called δ-endotoxins, that have insecticidal action. This has led to their use as insecticides, and more recently to genetically modified crops using Bt genes. Many crystal-producing Bt strains, though, do not have insecticidal properties.

The catalytic efficiencies of two different enzymes can be compared by the

  1. Km value

  2. pH optimum value

  3. molecular size of the enzymes

  4. formation of the product


Correct Option: A
Explanation:

 The catalytic efficiencies of two different enzymes can be compared by the Km value. Km is the Michaelis-Menten constant which shows the concentration of the substrate when the reaction velocity is equal to one half of the maximal velocity for the reaction.

Production of a human protein in bacteria by genetic engineering is possible because

  1. bacterial cell can carry out the RNA splicing reactions.

  2. the mechanism of gene regulation is identical in humans and bacteria.

  3. the human chromosome can replicate in bacterial cell.

  4. the genetic code is universal.


Correct Option: D
Explanation:

 Production of a human protein in bacteria by genetic engineering is possible because the genetic code is universal.

There are two opposing views about origin of modern man. According to one view Homoerrectus in Asia were the ancestors of modern man. A study of variation of DNA however suggested African origin of modern man. What kind of observation on DNA variation could suggest this?

  1. Greater variation in Asia than in Africa.

  2. Similar variation in Africa and Asia.

  3. Variation only in Asia and no variation in Africa.

  4. Greater variation in Africa than in Asia.


Correct Option: C
Explanation:

 More the genetic (DNA) variationthe more is the age of Mankind.Therefore greater variation in Africa than in asia suggested African origin of modern man.

Which of the following depresses brain activity and produces feelings of calmness, relaxation and drowsiness?

  1. Morphine

  2. Valium

  3. Hashish

  4. Amphetamines


Correct Option: B
Explanation:

 Valium is a medication of the benzodiazepine family that typically produces a calming effect. It is commonly used to treat a range of conditions including anxiety, alcohol withdrawal syndrome, benzodiazepine withdrawal syndrome, muscle spasms, seizures, trouble sleeping and restless legs syndrome.

Which group of thereof the following five statements (I - V) contains all three correct statements regarding beri-beri?

I. A crippling disease prevalent among the native population of sub-Saharan Africa. II. A deficiency disease caused by lack of thiamine (vitamin B1). III. A nutritional disorder in infants and young children when the diet is persistently deficient in essential protein.
IV. Occurs in those countries where the staple diet is polished rice. V. The symptoms are pain from neuritis, paralysis, muscle wasting, progressive oedema, mental deterioration and finally heart failure.

  1. II, III and V

  2. I, II and IV

  3. II, IV and V

  4. I, III and V


Correct Option: C
Explanation:

 Beriberi, nutritional disorder caused by a deficiency of thiamin (vitamin B1) and characterized by impairment of the nerves and heart. General symptoms include loss of appetite and overall lassitude, digestive irregularities, and a feeling of numbness and weakness in the limbs and extremities.In East Asian countries, where polished white rice is a dietary staple, beriberi has been a long-standing problem.

- Hide questions