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Biology (Medical Entrance) - 7

Description: Biology Mix Test - 7
Number of Questions: 25
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Tags: Biology Mix Test - 7 Adrenals Adrenal Gland Pancreas Pancreatic Gland Meiosis Aerobic Respiration Aerobic Respiration in Plants Transpiration
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In the human ovary, corpus luteum is responsible for

  1. milk production

  2. ovulation

  3. child birth

  4. retention of pregnancy


Correct Option: D
Explanation:

Corpus luteum secretes two pregnancy hormones: progesterone and relaxin.

During gametogenesis, how many sperms and ova will be produced from 25 primary spermatocytes and 25 primary oocytes, respectively?

  1. 100 sperms and 50 ova

  2. 100 sperms and 25 ova

  3. 50 sperms and 25 ova

  4. 100 sperms and 100 ova


Correct Option: B
Explanation:

One primary spermatocyte produces four sperms and one primary oocyte produces one ovum.

During the process of evolution, development of trichogyne of algae could be traced as

  1. style of angiosperm

  2. stigma of angiosperm

  3. gynoecium of angiosperm

  4. pollen tube of angiosperm


Correct Option: A
Explanation:

Trichogyne is a long hair-like receptive structure for male sperms.

Aldosterone is secreted by

  1. anterior pituitary gland

  2. adrenal medulla

  3. posterior pituitary gland

  4. adrenal cortex


Correct Option: D
Explanation:

 Adrenal cortex secretes aldosterone which increases water absorption in kidneys.

Which is an inhibitory hormone secreted by the pancreas?

  1. Glucagon

  2. Calcitonin

  3. Somatostatin

  4. Serotonin


Correct Option: C
Explanation:

Somatostatin secreted by pancreas inhibits the release of certain hormones like growth hormone.

Fight-or-flight response is the effect of

  1. epinephrine secreted by adrenal gland

  2. antidiuretic hormone secreted by the pituitary gland

  3. adrenocorticotropic hormone secreted by the pituitary gland

  4. insulin secreted by the pancreas


Correct Option: A
Explanation:

 Epinephrine secreted by the adrenal gland regulates stress responses.

Hyper-secretion of cortisol causes

  1. Addison's disease

  2. Cushing's syndrome

  3. Gigantism

  4. Sheehan syndrome


Correct Option: B
Explanation:

When levels of cortisol secreted by adrenal cortex increase in blood, a rare condition called Cushing's syndrome occurs indicated by weight gain, fragile skin and rounded face.

The interphase of meiosis lacks G2 phase

  1. in order to maintain the ploidy level of the progeny as that of parents

  2. in order to shorten the cell cycle in meiosis

  3. in order to release it from the cell cycle

  4. in order to help the cell to divide into four


Correct Option: A
Explanation:

 G2 phase is responsible for replication of the chromatin material resulting in the formation of similar sister homologous chromosomes, which maintain the ploidy status in the daughter nucleus, as in mitosis and if it occurs so in meiosis then the number of chromosomes will be doubled in the zygote and consequently in the progeny as that of parents and ploidy will be doubled in the progeny with each generation resulting in genetic abnormality.

Net ATP formed during oxidation of glucose molecule in aerobic prokaryotes is

  1. 36 ATP

  2. 40 ATP

  3. 38 ATP

  4. 34 ATP


Correct Option: C
Explanation:

 In prokaryotic cell during glycolysis, 2 ATP is consumed and 4 ATP and 2 NADH is produced from each glucose, and each NADH produces 3 ATP, thus a total of 4 + 6 ATP = 10 ATP and net production of 10 - 2 ATP = 8 ATP  is produced, and 30 ATP in kerb cycle and pyruvic acid oxidation, thus net production of 30+8 =38 ATP occurs. 

Which of the following states the importance of transpiration in plants?

  1. The low rate of transpiration will lead the plant to die.

  2. Without transpiration, the plant won't be able to photosynthesise.

  3. Without transpiration, plant cannot uptake water and nutrients from the soil.

  4. Its absence adversly affects overall funtioning of plants.


Correct Option: D
Explanation:

 Transpiration creates negative pressure in adjacent subsidiary cells of the stomata, which get transferred down the xylem, which results in uptake of the water and nutrients from the soil which is ultimately utilised in the process of photosynthesis. Thus, its absence can affect overall functioning of plants.

What is the importance of synaptonemal complex?

  1. It mediates in pairing of homologous chromosome during prophase 1 of meiosis.

  2. It helps in chiasma formation between chromosomes.

  3. It mediates in pairing of homologous chromosomes during prophase 2 of meiosis.

  4. It mediates in pairing of homologous chromosomes during prophase of mitosis.


Correct Option: A
Explanation:

 During prophase 1 of meiosis, homologous chromosome pair comes closer together and they are held in pairs with the help of protein structures called synaptonemal complex.

What are haploid and monoploid chromosomes?

  1. Haploid is half the number of genome in an individual while monoploid is presence of just one set of chromosomes.

  2. Haploid is n and monoploid is also n.

  3. Haploid is 2n and monoploid is n.

  4. Haploid is half the number of genome in an individual while monoploid is full set of genome.


Correct Option: A
Explanation:

 The gametes of an individual are haploid, i.e. they carry half the number of genome, similarly the other half comes from the gametes of the contributing parents, so that the number of genome is restored in the progeny to the parental level. Examples- Haploid of 2n is n, haploid of 4n is 2n. Similarly haploid of 6n is 3n. Monoploid means presence of just one set of chromosomes in the genome of an individual. Examples- Some species of potatoes are monoploid n. Humans are diploid, i.e. 23 (n) + 23 (n) = 46 (2n).

The most important contribution of heterospory is

  1. variation in the size of spores

  2. development of seed habit

  3. reduction in number of spores

  4. increased nutrition to some of the spores


Correct Option: B
Explanation:

 Heterospory results in the variation in the size of spores, which results in the formation of different sized spores, larger in female reproductive structure, which in the course of evolution gets modified into egg in the ovule and the smaller sized spores get modified into pollen grains, the male gametes. This modification results in fertilisation of egg in the ovary by male gametes derived from pollen grains and ultimately formation of seed.

The only means of gaseous movement within the plant body is

  1. cyclosis

  2. putrefaction

  3. diffusion

  4. imbibition


Correct Option: C
Explanation:

The only means of gaseous movement within the plant body is diffusion. Diffusion is the movement of particles of different substances including the gaseous particles from the region of higher concentration to the region of lower concentration.

The inhibitory effect of oxygen on the rate of photosynthesis is called as

  1. Warburg effect

  2. Pasteur effect

  3. Emerson effect

  4. Richmond-Lang effect


Correct Option: A
Explanation:

The inhibitory effect of oxygen on the rate of photosynthesis is called as Warburg effect.

In plants, water is transported by

  1. cambium

  2. phloem

  3. xylem

  4. endodermis


Correct Option: C
Explanation:

In plants, water is transported by xylem.

In CAM plants, the initial carbon dioxide acceptor is

  1. phosphoglyceric acid

  2. ribulose 1, 5- biphosphate

  3. oxalo-acetic acid

  4. phosphoenol pyruvic acid


Correct Option: D
Explanation:

In CAM plants, the initial carbon dioxide acceptor is phosphoenol pyruvic acid.

The dark reaction of photosynthesis occurs in

  1. grana lamellae of chloroplast

  2. stroma of chloroplast

  3. thylakoids of chloroplast

  4. stromas lamellae of chloroplast


Correct Option: B
Explanation:

The dark reaction of photosynthesis occurs in stroma of chloroplast.

Agranal chloroplast is found in

  1. C3 plants

  2. Halophytes

  3. C4 plants

  4. CAM plants


Correct Option: C
Explanation:

Agranal chloroplast is found in C4 plants.

During photorespiration, two glycerine molecules are converted to glycerate (a three-carbon molecule) and CO2. This process takes place in

  1. mitochondria

  2. peroxisome

  3. nucleus

  4. chloroplast


Correct Option: A
Explanation:

The glycine diffuses into a mitochondrion, where two glycine molecules are converted to glycerate (a three-carbon molecule) and CO2.

Mucopolysaccharide antifertilizin during fertilisation is secreted by

  1. sperm

  2. ovum

  3. zygote

  4. morula


Correct Option: A
Explanation:

Antifertilizin is secreted by animal sperm before fertilisation.

The rate of photosynthesis in plants is independent of

  1. intensity of light

  2. temperature

  3. duration of light

  4. quality of light


Correct Option: C
Explanation:

The rate of photosynthesis in plants is independent of duration of light.

Which of the following statements regarding transport of water in rooted plants is true?

  1. Always multidirectional

  2. Rarely unidirectional

  3. Directionless

  4. Always unidirectional


Correct Option: D
Explanation:

Transportation of water in rooted plants is always unidirectional.

If the external solution balances the osmotic pressure of the cytoplasm of a plant cell, then it is said to be

  1. hypertonic

  2. isotactic

  3. isotonic

  4. hypotonic


Correct Option: C
Explanation:

Isotonic solutions have equal solute concentrations.

Transportation of substances over longer distances in plants proceeds mainly by

  1. diffusion

  2. cytoplasmic streaming

  3. cyclosis

  4. translocation


Correct Option: D
Explanation:

In plants, transport of substances over longer distances proceeds mainly by translocation.

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