Protectors of biosphere - class-X
Description: protectors of biosphere | |
Number of Questions: 68 | |
Created by: Gauri Chanda | |
Tags: major activities of living organisms biology protectors of biosphere plant anatomy and plant physiology life process: nutrition, transportation, respiration, excretion |
Which of the following processes forms chemical potential energy from electromagnetic energy?
-
Respiration
-
Photosynthesis
-
Decomposition
-
Nitrogen fixation
-
Fermentation
Electromagnetic energy is the same as radiation or light energy. This type of kinetic energy can take the form of visible light waves, like the light from a candle or a light bulb, or invisible waves, like radio waves, microwaves, x-rays and gamma rays. Further, irrespective of where radiation is coming from, it can travel in a vacuum. The electromagnetic energy in plants can be converted to stored chemical energy during photosynthesis.
Which of the following is responsible for the red, orange and yellow colour of leaves?
-
Carotenoids
-
ATP
-
Leaf decay
-
Chlorophyll
-
Over abundance of water
Option 'A' is correct.
The factory for synthesis of sugars in autotrophic eukaryotes is
-
Chloroplast
-
Mitochondrion
-
Endoplasmic reticulum
-
Ribosome
Chloroplasts are the cell organelles where photosynthesis occurs. The light reactions occur in thylakoid membranes and dark reactions occur in stroma of chloroplasts. These reactions result in synthesis of sugars (glucose) in chloroplasts.
The light is trapped by photosynthetic pigments presents in the
-
Stroma
-
Grana
-
Quantosomes
-
Periplastidial space
The chloroplast is the cell organelles present in plant cells that are responsible for initiating the process of photosynthesis. Chloroplasts are double-membrane bound structures. The stroma of chloroplast is the jelly-fluid like structure in which another membrane system is presently called the thylakoids. These thylakoids are stacked upon each other to form the structure called grana. The grana are connected with each other by an extension of thylakoids called stroma lamellae. Thylakoid of grana has the photosynthetic pigments embedded in it that perform the trapping of sunlight and begin the light reaction of the photosynthesis.
Chloroplast stroma contains
-
Chlorophyll
-
Light dependent reaction enzymes
-
Light independent reaction enzymes
-
Ribosomes
In photosynthesis, light-independent reactions are known as dark reactions. This process does not depend directly on the presence of light but is dependent on the products of light reaction i.e., ATP and NADPH. The dark reactions occur through Calvin cycle. They take place in the stromal matrix of the chloroplast. Chloroplast stroma contains light independent reaction enzymes which are required for the reaction. Thus, the correct answer is option C.
Where does the primary photochemical reaction occurs in chloroplast ? Where does the light reaction of photosynthesis taken place?
-
Stroma
-
Endoplasmic reticulum
-
Quantasome or thylakoids (Grana)
-
Inner membrane of chloroplast
In the chloroplast, the primary photochemical reactions occur. During photosynthesis, primary reactions like the light-capturing and ATP-generating reactions occur on grana. Grana are stakes of thylakoids. Quantasomes are particles found in grana. During photosynthesis, the light-dependent reactions take place on the thylakoid membranes. The inside of the thylakoid membrane is called the lumen. Light-independent reactions take place in the stroma.
Which of the following absorb light energy for photosynthesis : -
-
Chlorophyll
-
Water molecule
-
O$ _{2}$
-
RUBP
In which of the following parts of the plant cell does photosynthesis occur?
-
The chloroplasts
-
The mitochondria
-
The nucleus
-
The endoplasmic reticulum
The green parts of the plants have the chlorophyll pigment containing chloroplasts. The chloroplast is a type of plastid which plays a major role in the photosynthesis process.
From the following, an organelle containing chlorophyll is
-
Chloroplast
-
Endoplasmic reticulum
-
Nucleus
-
Mitochondria
Who gave chemical compositions of chlorophyll and carotenoids?
-
Park and Biggins
-
Meyer and French
-
Willstatter and Stahl
-
Arnon and Benson.
Chlorophyll which is an essential factor in photosynthesis was first isolated and namedby Joseph Bienaime Caventou and Peter Joseph Pelletier but the chemical composition of the same was first elucidated by the German chemist Richard Willstatter followed by Hans Fischer. Carotenoids which are the organic pigments found in the chloroplasts and chromoplasts of plants and other photosynthetic organisms. These are oil-soluble molecules comprising of 40 branched
carbon units bonded together.
Cytochrome is a :
-
Mg containing pyrrole rings
-
Fe containing porphyrin ring
-
Nucleotide
-
Alloy of inchrome.
(B) Fe containing Porphyrin ring
If 24 G-3-P molecule are formed in $C _3$ plants. Calculate
a) the number of $CO _2$ used and
b) the number of $G3P$ used for regeneration $RuBP$ molecule.
-
a=12, b=20
-
a=24, b=48
-
a=12, b=24
-
a=20, b=12
The number of pigment molecules in quantasome are
-
250 - 400
-
300 - 900
-
500 - 600
-
50 - 100
- The thylakoid membrane of chloroplasts contain around 250-400 particles known as quantasomes. They are present on the surface of thylakoid discs in chloroplasts.
What percentage of water, proteins, lipids and pigments are present in chloroplasts respectively?
-
50, 25, 15 and 10
-
90, 5, 2 and 3
-
95, 2, 1 and 2
-
85, 10, 3 and 2
The chloroplasts are composed of the carbohydrates, lipids, proteins, chlorophyll, carotenoids (carotene and xanthophylls), DNA, RNA and certain enzymes and co-enzymes. The chloroplasts also contain some metallic atoms as Fe, Cu, Mn and Zn. By chemical analysis, these consist of lipids and proteins basically. Lipids are mainly phospholipid components of the membranes and lamellae. Proteins also contain enzymes, which are fully present in mature plastids. By the chemical analysis, it is observed that chloroplastids contain 90% of water, 5% of proteins, 2% of lipids and 3% of pigments.
Thylakoids possess photosynthetic units called
-
Photosystem.
-
Electron transport system.
-
Photolysis complex.
-
Photophosphorylation complex.
Thylakoid is a sheet-like membrane-bound structure which is the site of the light-dependent photosynthesis reactions within the chloroplasts and cyanobacteria. Photosystems are then functional and structural units of protein complexes involved in photosynthesis.
The electron transport chain is a series of the proteins and organic molecules which are found in the inner membrane of the mitochondria. Photolysis is the chemical process by which molecules are broken down into smaller units through the absorption of light.
The synthesis of ATP in chloroplasts, promoted by light, is termed as photophosphorylation
So the correct option is A.
Which pigment absorbs the red and far-red light?
-
Cytochrome
-
Phytochrome
-
Carotenoids
-
Chlorophyll
Phytochrome is a light sensitive pigment in plants and some bacteria and fungi. It exists in two interconvertible forms- Pr and Pfr. Pfr absorbs far red light of 730 nm wavelength. When it absorbs far red light, it converts to its original form, Pr. Thus Pfr is the active form of phytochrome which inhibits flowering.
Solarisation is a process in which
-
Sugars are formed with the help of solar energy
-
Chlorophyll is formed
-
Destrution of chlorophyll and ultimate death of protoplasmic compounds occurs
-
None of the above
Chlorophyll pigments trap sunlight during the process of photosynthesis but get destroyed on exposure to light of higher intensity. An exposure to high light intensity for even a small duration can be harmful. The destruction of chlorophyll when exposed to light of high intensity is called as solarization. It occurs due to irreversible chemical changes in the structure of chlorophyll molecule.
If a tree flowers thrice in a year, in the months of October, January and July in northern India the plant is
-
Photo and thermo-sensitive.
-
Photo and thermo-insensitive.
-
Photosensitive but thermo-insensitive.
-
Thermo-sensitive but photo-insensitive.
Plants are able to detect and respond to light, gravity, changes in temperature and chemicals. Plants respond to the changing seasons to initiate their development and flowering. The photoperiodic stimulus is found to be responsible for flowering, light quality, vernalization, autonomous and GA pathways are also responsible for regulating the flowering time in plants. While vernalization and photoperiodic pathways are environmental dependents, the autonomous pathway promotes flowering in all conditions. Hence for a tree that flowers thrice a year, the plant has to be both photo and thermo-insensitive.
Photosynthetic units are referred as
-
Quantasomes
-
Oxysomes
-
Phycobilisomes
-
$F _{1}$ particles
Photosynthetic units are referred as quantasomes. Quantasomes are particles found in the thylakoid membrane of chloroplasts in which photosynthesis takes place.
Isotopes employed to study the process of photosynthesis reaction are
-
$S^{68}\, and\, P^{32}$
-
$C^{14}\, and\, O^{18}$
-
$N^{14}\, and\, Co^{60}$
-
$N^{14}\, and\, O^{18}$
Photosynthesis is a redox reaction in which carbon dioxide is reduced to sugars in dark reaction and water is oxidised to release oxygen in light reaction of photosynthesis. $C^{14}$ label was used to trace the path of carbon in the dark reaction in $C _3$ plants by Calvin, Benson and Basham. The $O^{18}$ label was used by Rumen and Kamen to experimentally prove that the source of oxygen released during light reaction of photosynthesis is water.
Phytochrome is found in
-
Algae.
-
Virus.
-
Gymnosperms.
-
Angiosperms.
The main photoreceptor for photoperiodism and many other light initiated plant responses (such as germination and seedling establishment) is phytochrome. It is a family of about five blue-green pigment proteins, each of which is coded for by a different gene in higher plants, like angiosperms.
Which of the following is not characterized as an organelle?
-
Nucleus
-
Golgi apparatus
-
Lysosome
-
Chlorophyll
-
Chloroplast
The eukaryotic cell also possesses several membrane-bound organelles. The cell is composed of the nucleus, Golgi complex, lysosome, chloroplast, mitochondria, etc. Chlorophyll is the coloured pigment inside the chloroplast which is involved in the process of photosynthesis.
Which of the following is true about photosynthesis?
-
Light driven
-
Photo driven
-
Anabolic
-
Enzyme moderated
-
All of the above
Option 'E' is true.
Which of the following organelle acts as a site for photosynthesis in plants?
-
Ribosome
-
Mitochondria
-
Chloroplast
-
Endoplasmic reticulum
-
Golgi apparatus
The process of photosynthesis takes place in the chloroplasts, using chlorophyll, the green pigment involved in photosynthesis. Chloroplasts absorb sunlight and use it in conjunction with water and carbon dioxide gas to produce food for the plant. Chloroplasts capture light energy from the sun to produce the free energy stored in ATP and NADPH through a process called photosynthesis.
An association is found between the wavelengths of light absorbed by chlorophyll and wavelengths of length that are associated with the greatest amount of oxygen released by plants. Based on the observation, the function of chlorophyll is
-
It plays a role in cell respiration.
-
It plays a role in the light reactions of photosynthesis.
-
It takes part in $H _2O$ release.
-
It takes part in $CO _2$ fixation.
-
It generates energy.
Chlorophyll absorbs sunlight of particular wavelength that causes spitting of water at water splitting complex of photosystem II and oxygen gas is released. PSI absorbs light below 680nm while PS II is activated by light below 700 nm; so plants exhibit maximum amount of oxygen released when illuminated with simultaneous exposure to red and far red light. Fixation of $CO _2$ occurs during the dark reaction. Thus, the correct answer is B.
Total amount of dry weight of photosynthate produced by all type of plants per annum is
-
1.7 million tonnes
-
17 million tonnes
-
17000 million tonnes
-
170000 million tonnes
Total amount of dry weight of photosynthate produced by all type of plants per annum is 170000 million tonnes. There are several factors, which limit the formation of dry weight such as reduced nitrogen fixation which will result in reduction of dry weight.
The site of photosynthesis in blue green algae is
-
Chromatophores
-
Mitochondria
-
Chloroplast
-
Root hair
Blue green algae are prokaryotic orgnanisms and lack membrane bound organelles. Mitochondria and cholroplast are double membrane bound organelles of eukaryotes that serve as site of aerobic respiration and photosynthesis respectively. Chromatophores are the pigment containing membranous structures that serve as site for photosynthesis in BGA. Correct answer is A.
The term thylakoid was coined by
-
Arnon
-
Park and Biggins
-
Menke
-
Willstatter
- Thylakoid (internal photosynthetic membranes) is a membrane-bound compartment present within the cellular organelle called chloroplast, they are also present in cyanobacteria.
- It is a site for the light-dependent reactions of photosynthesis.
- It is made up of a thylakoid membrane which surrounds the thylakoid lumen.
- The term thylakoid was coined by Menke in the year 1962.
- So, the correct answer is 'Menke'.
Intact chloroplasts can be isolated with the help of
-
Alcohol
-
Acetone
-
Carbon disulphide
-
Sugar solution
Intact chloroplast from green leaves can be isolated by the acetone isolation method. The membranes of the chloroplast are proteinaceous in nature so it can be easily isolated by acetone. The samples obtained are loaded to the chromatography apparatus, which shows bands on the chromatogram.
So, the correct option is B.
Thylakoids occur inside
-
Mitochondria
-
Chloroplasts
-
Golgi apparatus
-
Endoplasmic reticulum
- Thylakoid (internal photosynthetic membranes) is a membrane-bound compartment present within the cellular organelle called chloroplast, they are also present in cyanobacteria.
- It is a site for the light-dependent reactions of photosynthesis.
- It is made up of a thylakoid membrane which surrounds the thylakoid lumen.
- So, the correct answer is 'Chloroplasts'.
Number of membranes separating intrathylakoid space from cytoplasm is
-
4
-
3
-
2
-
1
The chloroplasts are double membrane-bound organelle that is found in the cytoplasm. They have membrane-bound thylakoids in which the photosynthesis takes place. The cytoplasm is thus separated from the intrathylakoid space by 3 membranes. i.e the 2 membranes of the chloroplast, and some membrane of thylakoid.
Grana are
-
Protein storing plastids
-
Coloured plastids
-
Stacks of thylakoids
-
Individual thylakoids present in stroma
- A stack of thylakoid discs is organized to form grana.
- A thylakoid refers to the membrane-bound internal compartment within the chloroplasts of a plant cell and cyanobacteria.
- It is a site for light-dependent reactions of photosynthesis.
- There are about 10 to 100 thylakoid discs within a granum and about 40- 60 grana in a plant cell.
- So, the correct answer is 'Stacks of thylakoids'.
In Ulothrix, the shape of chloroplast is
-
Star-shaped
-
Cup-shaped
-
Girdle-shaped
-
Diffused type
- Ulothrix is a genus of filamentous green algae which are found in marine and fresh waters habitats.
- They have a single girdle-shaped or band-shaped chloroplast near the peripheral region of the cytoplasm (near the cell wall).
- So, the correct answer is 'Girdle-shaped'.
Structure associated with chloroplast of green algae is
-
Pyrenoid
-
Stigma
-
Both A and B
-
Endoplasmic reticulum
- The structure associated with chloroplast of green algae is pyrenoid and stigma.
- Pyrenoid refers to the cellular microcompartments present within the chloroplasts of the cell of green algae and is a major component of the algal carbon concentrating mechanism.
- Stigma or eyespot is part of a chloroplast which is found in the motile cells of green algae and helps in finding optimal light conditions for photosynthesis.
- So, the correct answer is 'Both A and B'.
Number of grana present in a chloroplast is
-
10-20
-
20-30
-
30-40
-
40-60
- A thylakoid refers to the membrane-bound internal compartment within the chloroplasts of a plant cell and cyanobacteria.
- It is a site for light-dependent reactions of photosynthesis.
- It is made up of a thylakoid membrane which surrounds the thylakoid lumen.
- A stack of thylakoid disk is organized to form grana.
- Within a chloroplast of a plant cell, there are about 40- 60 grana and each granum are composed of 10 to 100 thylakoids.
- So, the correct answer is '40-60'.
Particles of thylakoid membranes involved in ATP synthesis are called
-
Quantasomes
-
$CF _0-CF _1$
-
Photosystems
-
Pyrenoids
- The particles of thylakoid membrane responsible for ATP synthesis is a CF$ _1$ -CF$ _O$-ATP synthase.
- It is embedded in the thylakoid membrane where the CF$ _1$-part is attached to the stroma.
- Therefore, ATP synthesis occurs on the stromal side of the thylakoid where the ATP molecules are required for carrying out the light-independent reactions of photosynthesis.
- So, the correct answer is 'CF$ _0$−CF$ _1$'.
Shape of chloroplast in higher plant is
-
Discoid
-
Girdle-shaped
-
Reticulate
-
Cup-shaped
- The chloroplast is a discoid plastid which contains chlorophyll (green pigment) within the thylakoid membranes of the organelle.
- This organelle is present in the green parts of plants where photosynthesis takes place.
- It is the main site of synthesis of glucose by the process called photosynthesis.
- The chlorophyll pigment captures the sunlight and converts it into chemical energy and thus, helps in the process of photosynthesis.
- So, the correct answer is 'Discoid'.
Number of thylakoids in a granum is
-
10-100
-
5-10
-
100-200
-
200-500
- A thylakoid refers to the membrane-bound internal compartment within the chloroplasts of a plant cell and cyanobacteria.
- It is a site for light-dependent reactions of photosynthesis.
- It is made up of a thylakoid membrane which surrounds the thylakoid lumen.
- A stack of thylakoid disk is organized to form grana.
- There are about 10 to 100 thylakoids within a granum and about 40- 60 grana in a plant cell.
- So, the correct answer is '10-100'.
Quantasomes occur in
-
Stroma
-
Grana/chloroplast
-
Golgi body
-
Mitochondria
- Quantasomes occur in the Grana/chloroplast.
- Quantasomes can be defined as small particles found in the thylakoid membrane of the chloroplasts.
- These particles are embedded in a paracrystalline form on the surface of thylakoid discs in chloroplasts.
- So, the correct answer is 'Grana/chloroplast'.
All types of plastids possess essentially the same structure because they
-
Perform the same function.
-
Store food materials like starch, fat and protein.
-
Occur in aerial parts.
-
Can transform from one form to another.
Plastids are considered as sac-like organelles, generally involved in the formation or storage of food. These are chloroplast, chromoplast and leucoplast and are same in their structure to transform into one another during the requirement.
Lipid content of chloroplast is
-
20-30%
-
5-10%
-
4-5%
-
1-2%
- Plastids are a pigment containing double membrane-bound organelle which is the site of manufacture and storage of chemical compounds.
- The chloroplast is a plastid which contains the green coloured pigment called chlorophyll and are present in the green parts of the plants that take part in the process called photosynthesis.
- The outer chloroplast envelope is made up of lipid (20%-30%).
- So, the correct answer is '20-30%'.
The packet of thylakoids in a chloroplast is called
-
Fret channels
-
Granum
-
Stroma thylakoid
-
Photosynthetic thylakoid
- A stack of thylakoid discs is organized to form grana.
- A thylakoid refers to the membrane-bound internal compartment within the chloroplasts of a plant cell and cyanobacteria.
- It is a site for light-dependent reactions of photosynthesis.
- There are about 10 to 100 thylakoid discs within a granum and about 40- 60 grana in a plant cell.
- So, the correct answer is 'Granum'.
Electron carriers involved in photophosphorylation are located in
-
Outer chloroplast membrane
-
Inner chloroplast membrane
-
Stroma
-
Thylakoid membranes
The photophosphorylation reaction involves the conversion of ADP to ATP in the presence of sunlight. This takes place in the thylakoid membrane. The photosystem I and II that involves the electron carriers; are present in the thylakoid membranes of the chloroplast. here the light reaction of photosynthesis takes place.
Stroma is the ground matrix of
-
Lysosomes
-
Oxysomes
-
Ribosomes
-
Chloroplast.
Stroma, refers to the colourless fluid surrounding the grana within the chloroplast. Within the stroma are grana, stacks of thylakoids, the sub-organelles, where photosynthesis is commenced before the chemical changes are completed in the stroma. The internal space enclosed by the chloroplast double membrane but excluding the thylakoid space. This space, filled with a colorless hydrophilic matrix, contains DNA, ribosomes and some temporary products of photosynthesis also known as chloroplastic stroma.
Match the columns and identify the correct option.
I | II | ||
---|---|---|---|
(a) | Thylakoids | (i) | Disc shaped sacs in Golgi apparatus |
(b) | Cristae | (ii) | Condensed structure of DNA |
(c) | Cisternae | (iii) | Flat membranous sacs in stroma |
(d) | Chromatin | (iv) | Infoldings in mitochondria |
-
a-iv, b-iii, c-i, d-ii
-
a-iii, b-iv, c-i, d-ii
-
a-iii, b-i, c-iv, d-ii
-
a-iii, b-iv, c-ii, d-i
Photosynthetic pigments found in the chloroplasts occur in
-
Thylakoid membranes
-
Plastoglobules
-
Matrix
-
Chloroplast envelope.
Photosynthetic or chloroplasts pigments that are found in the thylakoid membrane constitute grana of chloroplasts are the organic molecules that absorb light of specific wavelengths in the visible region due to the presence of conjugated double bonds and are chlorophyll a and b, carotenoids and xanthophylls.
Chloroplasts stroma of higher plants contains
-
Chlorophyll
-
Light dependent reaction enzymes
-
Light independent reaction enzymes
-
Lysosomes
A) Chlorophyll is located within the thylakoid membrane. But chlorophyll is present in both lower (algae) and higher plants and some bacteria as well.
B) The light-dependent reactions use light energy to make ATP and NADPH. This is also seen in lower plants.
D) Lysosomes are usually present in animal cells. They can be present in lower plants.
So the correct answer is 'Light independent reaction enzymes'.
Dimorphic chloroplasts occur in
-
Pea
-
Mango
-
Sugarcane
-
Cotton
Chloroplast of C4 plants is dimorphic chloroplast because it shows two different types of the chloroplast.
1). The chloroplast with grana
2). Chloroplast without grana and surrounded to the vascular bundle.
The chloroplast is of 2 different types hence it's called as the dimorphic chloroplast. And it is best seen among sugarcane of the C4 plants.
So, the correct option is 'Sugarcane'.
Cytochrome $b _6$ and cytochrome f occur in
-
Ribosomes
-
Mitochondria
-
Chloroplasts
-
Lysosomes
Ground substance of chloroplast is
-
Stoma
-
Stroma
-
Granum
-
Cisterna.
In chloroplast, the highest number of protons are found in
-
Antenna complex
-
Stroma
-
Lumen of thylakoids
-
Inter-membrane space
During photosynthetic electron transport, protons (H$^+$) accumulate in the thylakoid space. These protons are released into thylakoid space after each split of water molecule during photooxidation and after each electron transport between PQH$ _2$ to cytochrome-f. Increase in the number of protons in the thylakoid space results in an increase in a proton gradient.
Chlorophyll molecules are located in
-
Thylakoid membrane
-
Thylakoid lumen
-
Stroma
-
Inner chloroplast membrane
A) The green pigment chlorophyll is located within the thylakoid membrane.
D) The inner chloroplast membrane does not contain any pigments.
So the correct answer is 'Thylakoid membrane'.
Thylakoids possess photosynthetic units called
-
Quantasomes
-
Glyoxysomes
-
Polysomes
-
Ribosomes
Quantasomes are particles found in the thylakoid membrane of chloroplasts in which photosynthesis takes place. They are embedded in a paracrystalline array on the surface of thylakoid discs in chloroplasts.
Abscises acid is synthesized in.
-
Chloroplasts
-
Endoplasmic reticulum
-
Ribosome's
-
Peroxisomes
Copper-containing blue protein found in the chloroplast is the.
-
Plastocyanin
-
Plastoquinone
-
Cytochrome f
-
Ferredoxin
Extrusion or passage of chromatin from one cell into the cytoplasm of the adjoining cell is due to.
-
Cytomixis
-
Cytokinesis
-
Inversions
-
Translocation
Photosynthetic Active Radiation (PAR) has the following range of wavelengths
-
340-450 nm
-
450-950 nm
-
500-600 nm
-
400-700 nm
Lowest pH inside chloroplast in day time must be found in _______________.
-
Stroma
-
Lumen
-
Intermembrane space
-
Thylakoid membrane
The individual flattened stacks of membranous structures inside the chloroplasts are known as:
-
Grana
-
Stroma
-
Thylakoids
-
Cristae
How many structures are of sporophytic origin?
Megasporocyte, Endothecium, Generative cell, Nucellus, Embryo sac, Sporogenous cell, Stigma. Integument
-
Six
-
Five
-
Four
-
Seven
Which one is not character of antennae?
-
To make photosynthesis more efficient
-
To make wider range of absorption of incoming light
-
Provide electron to primary electron acceptor of photosystem
-
Reaction center is not part of it
The light harvesting complexes are made up of hundreds of pigment molecules bound to proteins. Each photosystem has all the pigments (except one molecule of chlorophyll a) forming a light harvesting system also called antennae. These pigments help to make photosynthesis more efficient by absorbing different wavelengths of light. The single chlorophyll a molecules form the reaction center. Therefore, the reaction center is not a part of antennae.
Read the given statements A & B and choose the correct option.
A. The ribosomes of the chloroplasts are smaller than the cytoplasmic ribosomes.
B. Chloroplasts can synthesise some of their proteins but they receive other proteins from cytoplasm.
-
Only statement A is correct.
-
Only statement B is correct.
-
Both statements are correct.
-
Both statements are incorrect.
A. Chloroplast ribosomes are similar to those found in the prokaryotes that is 70s type. Eukaryotic ribosomes which are found in the cytoplasm are of 80stype.
In a chlorophyll molecule, the magnesium is situated in the
-
corners of porphyrin
-
centre of porphyrin
-
isocyclic ring
-
phytol chamber
A chlorophyll molecule has a hydrophobic "tail" that embeds the molecule into the thylakoid membrane. The "head" of a chlorophyll molecule is a ring called a porphyrin. The porphyrin ring of chlorophyll, which has a magnesium atom at its centre, is the part of a chlorophyll molecule that absorbs light energy.
Enzymes required for photophosphorylation are located in ............ of chloroplast.
-
Peristromium
-
Plastidome
-
Stroma
-
Quantasome
A) The peristomium is the first true body segment in an annelid worm's body in the anterior end.
Quantasome is a unit related to
-
Respiration
-
Ascent of sap
-
Growth
-
Photosynthesis
A) Quantasomes are not involved in respiration.
B) Xylem is involved in the ascent of sap. Quantasomes do not play a part in the ascent of sap.
On what basis, paper chromatography separates plant pigments?
-
The non - polarity of the solvents and pigments
-
The polarity of the paper
-
The polarity of the pigments
-
All of the above
-
None of the above
Paper chromatography is a technique that is used in the laboratories to separate plant pigments. The concept used is that this helps to separate the mixture into its component molecules. The molecules migrate, or move up the paper, at different rates because of differences in solubility, molecular mass, and hydrogen bonding with the paper.