Category: Class 11 Biology Objective Questions

Biology Multiple Choice Questions on “Animals Structural Organisations – Earthworm – 1”.

1. Earthworm is a(n) ______
a) terrestrial vertebrate
b) aquatic vertebrate
c) aquatic invertebrate
d) terrestrial invertebrate
Answer: d
Clarification: Earthworm is a long cylindrical worm belonging to class Annelida. It does not have a backbone and hence it is an invertebrate. It is terrestrial and inhabits the upper layers of the soil.

2. Which of the following statements about earthworms is true?
a) They are vertebrates
b) They do not live in burrows
c) They can be traced by fecal deposits
d) They inhabit the lower layers of the soil
Answer: c
Clarification: Earthworms can be traced by fecal deposits or worm castings. They are invertebrates as they lack a backbone and a bony skeleton. They live in burrows in the upper layers of the soil.

3. What are the common Indian earthworms?
a) Lacertilia, Pheretima
b) Periplaneta, Lumbricus
c) Pheretima, Lumbricus
d) Periplaneta, Pheretima
Answer: c
Clarification: Pheretima and Lumbricus are the common Indian earthworms. It is a terrestrial invertebrate with a long cylindrical body. Periplaneta is a genus of the cockroach family, while Lacertilia is the genus of the lizard family.

4. What is the median mid dorsal line present along the length of an earthworm?
a) Dorsal blood vessel
b) Dorsal root ganglion
c) Prostomium
d) Clitellum
Answer: a
Clarification: The dorsal blood vessel is present along the length of the earthworm’s body. It is seen as a dark median line. Prostomium covers the mouth while clitellum is a band of glandular tissue covering the 14^th to 16^th segments.

5. Which of the following statements is true about prostomium?
a) It is present in the posterior end of the earthworm
b) It acts as a wedge to open cracks in the soil
c) It is the mouth of the earthworm
d) It does not have a sensory function
Answer: b
Clarification: The prostomium is located in the anterior end of the earthworm. It is a covering of the mouth and has a sensory function. It also acts as a wedge to open cracks in the soil. It is the first segment of the body of the earthworm.

6. The first body segment of the earthworm is the _____
a) male genital aperture
b) female genital aperture
c) peristomium
d) clitellum
Answer: c
Clarification: Peristomium or buccal segment is the first body segment of the earthworm. It is the mouth part. The genital apertures and clitellum are located towards the middle of the body of the earthworm.

7. Clitellum is a ______
a) glandular tissue
b) muscular tissue
c) neural tissue
d) connective tissue
Answer: a
Clarification: Clitellum is a glandular tissue. It appears as a prominent dark band. The clitellum covers the 14^th to 16^th segment of the body of the mature earthworm. This glandular tissue contains secretory cells.

8. What is present on the 5^th to 9^th segments of the earthworm’s body?
a) Clitellum
b) Peristomium
c) Female genital pore
d) Spermathecal apertures
Answer: d
Clarification: On the sides of the intersegmental grooves of the 5^th to 9^th segment, spermathecal apertures are present. They are eight in number. The peristomium is the first segment while the clitellum is the glandular tissue covering the 14^th to 16^th segment.

9. Where is the female genital pore present in earthworm?
a) 16^th segment
b) 18^th segment
c) 14^th segment
d) 9^th segment
Answer: c
Clarification: The female genital pore of the earthworm is present in the mid – ventral line of the 14^th segment. It is a single pore. The male genital pores are two in number. It is present on the 18^th segment. Earthworms are hermaphrodites.

10. Where are the male genital pores present in earthworm?
a) 16^th segment
b) 18^th segment
c) 14^th segment
d) 9^th segment
Answer: b
Clarification: The male genital pores of the earthworm are present on the ventral lateral sides of the 18^th segment. They are two in number. The earthworm also contains a female genital pore as it is a hermaphrodite.

11. What is the main role of setae in earthworm?
a) Storage of food
b) Respiration
c) Reproduction
d) Locomotion
Answer: d
Clarification: The principal role of setae in earthworm is locomotion. It is present in every body segment except the first, the last and the clitellum. Reproduction is carried out by the female and male genital pores present at other segments.

12. What are the pores present on the surface of the body of the earthworm called?
a) Polypore
b) Exospore
c) Nephridiopore
d) Zoospore
Answer: c
Clarification: Nephridiopore is present on the surface of the earthworm’s body. They are numerous in number. They are minute in size. Polypore, exospore and zoospore are not associated with earthworm but with fungi.

13. Identify the part of earthworm shown in the picture below.

a) Female genital pore
b) Male genital pore
c) Anus
d) Clitellum
Answer: c
Clarification: The anus is the last segment of the earthworm. Since the mouth segment peristomium is shown, it implies that the segment at the opposite end should be the anus. The female and male genital pores and the clitellum are located in the middle of the body.

14. The epidermal pits in the middle of each segment of the earthworm contains _____
a) setae
b) clitellum
c) nephridiopores
d) typhlosole
Answer: a
Clarification: The location of setae is mid – segmental in the epidermal pits. They are S – shaped and present in rows. The main function of the setae is to help with locomotion. They are extendable and retractable.

15. Which of the following statements is true about setae present in earthworm?
a) They are used for reproduction
b) They are retractable
c) They are L – shaped
d) They cannot be extended
Answer: b
Clarification: Setae are both extendable and retractable. They are S – shaped and present in the epidermal pits in the mid – segmental region of every segment. The principal function of the setae is locomotion.

Biology Multiple Choice Questions on “Eukaryotic Cells and it’s Organelles – 3”.

1. Identify the structure.

a) Mitochondria
b) Nucleus
c) Golgi apparatus
d) Endoplasmic reticulum
Answer: d
Clarification: The structure shown in the diagram is the endoplasmic reticulum. Its membrane, which is a phospholipid bilayer, is continuous with the membrane of the nucleus. Rough endoplasmic reticulum is shown here.

2. What is the space inside the endoplasmic reticulum called?
a) Tubular compartment
b) Extra – tubular compartment
c) Luminal compartment
d) Extra – luminal compartment
Answer: c
Clarification: The endoplasmic reticulum is an organelle whose membrane is continuous with the membrane of the nucleus. It divides the intracellular space into two compartments – luminal and extra – luminal.

3. Where are the ribosomes attached in rough endoplasmic reticulum?
a) In the lumen
b) On the folds towards the nucleus
c) On the surface
d) On the folds towards the cell membrane
Answer: c
Clarification: Endoplasmic reticulum is of two types- smooth endoplasmic reticulum and rough endoplasmic reticulum. The rough endoplasmic reticulum has ribosomes present on its outer surface.

4. What is present on the surface of the rough endoplasmic reticulum?
a) Ribosomes
b) Peroxisomes
c) Lysosomes
d) Endosomes
Answer: a
Clarification: Endoplasmic reticulum is of two types- smooth endoplasmic reticulum and rough endoplasmic reticulum. The rough endoplasmic reticulum has ribosomes present on its outer surface.

5. Endoplasmic reticulum without ribosomes is called ______
a) rough endoplasmic reticulum
b) smooth endoplasmic reticulum
c) non – ribosomal endoplasmic reticulum
d) nuclear endoplasmic reticulum
Answer: b
Clarification: Endoplasmic reticulum is of two types – smooth endoplasmic reticulum and rough endoplasmic reticulum. The rough endoplasmic reticulum has ribosomes present on its outer surface.

6. Which of these cell organelles is involved in protein synthesis?
a) Lysosome
b) Smooth endoplasmic reticulum
c) Rough endoplasmic reticulum
d) Peroxisome
Answer: c
Clarification: The rough endoplasmic reticulum contains ribosomes on its surface. Hence, the rough endoplasmic reticulum is actively involved in protein synthesis. Smooth endoplasmic reticulum is involved in lipid synthesis.

7. Which of these statements is not true regarding rough endoplasmic reticulum?
a) The inner compartment is called the tubular compartment
b) It is involved in protein synthesis
c) Ribosomes are attached to its outer surface
d) Its membrane is continuous with the outer membrane of the nucleus
Answer: a
Clarification: The inner compartment of the rough endoplasmic reticulum is called the luminal compartment. The ribosomes are attached to the outer surface and it is actively involved in protein synthesis.

8. What is the site of production of lipid-like steroidal hormones in animal cells?
a) Mitochondria
b) Nucleus
c) Peroxisomes
d) Smooth endoplasmic reticulum
Answer: d
Clarification: Smooth endoplasmic reticulum is the site of synthesis of lipid-like steroidal hormones. It is the major site for the production of lipids. Rough endoplasmic reticulum is the site of synthesis of proteins.

9. What is the diameter of cisternae of Golgi bodies?
a) 5μm to 10μm
b) 0.05μm to 0.1μm
c) 0.5μm to 1.0μm
d) 50μm to 100μm
Answer: c
Clarification: Golgi bodies were named after the scientist who discovered them, Camillo Golgi. Golgi bodies contain flat, disc – shaped sacs called cisternae. The diameter of the cisternae is 0.5μm to 1.0μm.

10. The forming face of the Golgi complex is convex. True or false?
a) True
b) False
Answer: a
Clarification: The Golgi complex is made of sacs called cisternae. The forming face which faces the nucleus is convex or cis, while the maturing face which faces away from the nucleus is concave or trans.

11. Which of these is not a function of the Golgi apparatus?
a) Packaging of proteins
b) Modification of proteins
c) Synthesis of glycoproteins and glycolipids
d) Synthesis of proteins
Answer: d
Clarification: Golgi bodies are involved in the synthesis of glycoproteins and glycolipids. They are also involved in the modifications and packaging of proteins received from the endoplasmic reticulum. It does not synthesize proteins.

12. Which of these is not a lysosomal enzyme?
a) Lipases
b) Protease
c) Kinases
d) carbohydrase
Answer: c
Clarification: The lysosome contains various enzymes collectively known as lysosomal acid hydrolases. The enzymes are hydrolytic enzymes such as lipase, protease and carbohydrase. Kinases are not hydrolytic enzymes.

13. Which of these statements is false regarding lysosomes?
a) They are bound by a single membrane
b) They contain hydrolytic enzymes
c) Lysosomal enzymes are active at a basic pH
d) They can digest nucleic acids
Answer: c
Clarification: Lysosomes are bound by a single membrane. The contain hydrolytic enzymes which are active at an acidic pH and digest substances such as carbohydrates, proteins, lipids and nucleic acids, by hydrolysis.

14. What are the membranes of vacuoles called?
a) Tonoplast
b) Leucoplast
c) Amyloplast
d) Chromoplast
Answer: a
Clarification: Vacuoles are covered by a single membrane known as tonoplast. Vacuoles contain substances for storage such as water, or excretory products such as sap and other materials not useful for the cell.

15. Which of these is a function of the contractile vacuole in Amoeba?
a) Lipoprotein synthesis
b) Osmoregulation of the cell
c) Glycoprotein synthesis
d) Degradation of nucleic acids
Answer: b
Clarification: Vacuoles contain substances for storage such as water, or excretory products such as sap and other materials not useful for the cell. the contractile vacuole in Amoeba is responsible for osmoregulation and excretion.

Biology Multiple Choice Questions on “Biomolecules – Nuclei Acids”.

1. Which of these is present in the acid insoluble fraction of living tissue?
a) ascorbic acid
b) Magnesium
c) Riboflavin
d) DNA
Answer: d
Clarification: DNA is present in the acid insoluble fraction. It is a macromolecule. Riboflavin or vitamin B₂, magnesium and ascorbic acid or vitamin C are present in the acid soluble fraction of living tissue.

2. Nucleic acids are _____
a) polypeptides
b) polyimides
c) polynucleotides
d) polysaccharides
Answer: c
Clarification: Nucleic acids are chains of nucleotides. Thus, they are called polynucleotides. Each nucleotide contains a pentose sugar, a phosphate group and a nitrogenous base. Nucleic acids are the genetic material.

3. Which of these is not a part of the macromolecular fraction of a cell?
a) Polynucleotides
b) Polysaccharides
c) Riboflavin
d) Polypeptides
Answer: c
Clarification: The macromolecular fraction of the cell consists of polynucleotides or nucleic acid, polypeptides and polysaccharides which are carbohydrates. All of their molecular wights are above 10,000 Da.

4. What is the building block of nucleic acids?
a) Nucleotide
b) Nucleoside
c) Nucleosome
d) Nucleoprotein
Answer: a
Clarification: The building blocks of nucleic acids are nucleotides. Each nucleotide consists of a pentose sugar, a phosphate group and a nitrogenous base such as adenine, guanine, cytosine, thymine or uracil.

5. How many distinct components does each nucleotide contain?
a) 2
b) 3
c) 1
d) 4
Answer: b
Clarification: Each nucleotide consists of a pentose sugar, a phosphate group and a nitrogenous base such as adenine, guanine, cytosine, thymine or uracil. They are the building blocks of nucleic acids which are the genetic material.

6. How many distinct components does each nucleoside contain?
a) 3
b) 1
c) 2
d) 4
Answer: c
Clarification: Each nucleoside consists of a pentose sugar and a nitrogenous base such as adenine, guanine, cytosine, thymine or uracil. When a phosphate group attaches to the nucleoside, it forms a nucleotide.

7. Which of these components of nucleotides is heterocyclic?
a) Adenine
b) Phosphoric acid
c) Monosaccharide
d) Phosphate
Answer: a
Clarification: Nucleotides are the building blocks of nucleic acids. Each nucleotide contains a phosphate group, a nitrogenous base and a pentose sugar. The nitrogenous bases are heterocyclic in nature.

8. Which monosaccharide is present in nucleic acid?
a) Fructose
b) Galactose
c) Glucose
d) Ribose
Answer: d
Clarification: Glucose, fructose, galactose and ribose are all monosaccharides. The monosaccharide contained in nucleic acid is ribose and deoxyribose. They are pentose sugars. Ribose sugar is present in RNA while deoxyribose sugar is present in DNA.

9. The phosphate groups present in nucleotides are related to ______
a) pyrophosphoric acid
b) phosphorous acid
c) phosphoric acid
d) metaphosphoric acid
Answer: c
Clarification: The phosphate groups present in nucleotides and hence, nucleic acids are related to phosphoric acid. Each nucleotide contains a phosphate group, a nitrogenous base and a pentose sugar.

10. The distinct components of nucleotides are phosphate group, heterocyclic compound and polysaccharide. True or false?
a) True
b) False
Answer: b
Clarification: Nucleotides are the building blocks of nucleic acids. Each nucleotide contains a phosphate group, a nitrogenous base which is a heterocyclic compound and a pentose sugar, which is a monosaccharide.

11. Which of these is a substituted purine?
a) Cytosine
b) Thymine
c) Uracil
d) Guanine
Answer: d
Clarification: Adenine and guanine are the substituted purines. The substituted pyrimidines are cytosine, thymine and uracil. They are the nitrogenous bases present in nucleic acids along with pentose sugar and phosphate group.

12. What type of sugar does DNA contain?
a) Ribose
b) 3’ deoxyribose
c) 2’ deoxyribose
d) 5’ deoxyribose
Answer: c
Clarification: DNA stands for deoxyribonucleic acid. Hence, it contains deoxyribose sugar. It is a ribose sugar molecule with an oxygen atom removed from the second carbon. Hence, it is a 2’ deoxyribose sugar.

13. Identify the compound.

a) Adenine
b) Adenylic acid
c) Adenosine
d) Adenylyl cyclase
Answer: c
Clarification: The given structure contains a pentose sugar and the nitrogenous base adenine attached to it. There is no phosphate group present in the structure. Hence, it is the nucleoside adenosine.

14. Identify the compound.

a) Uridine
b) Uracil
c) Uridine monophosphate
d) Uridylic acid
Answer: a
Clarification: The given structure contains a pentose sugar and the nitrogenous base uracil attached to it. There is no phosphate group present in the structure. Hence, it is the nucleoside uridine.

15. Identify the compound.

a) Adenine
b) Adenylic acid
c) Adenosine
d) Adenylyl cyclase
Answer: b
Clarification: The given structure contains a phosphate group, pentose sugar and the nitrogenous base adenine (purine) attached to it. Hence, it is the nucleotide adenylic acid. It is an ester of phosphoric acid and the nucleoside adenosine.

Botany Objective Questions and Answers on “Long Distance Transport of Water”.

1. The movement of chloroplast in cells of Hydrilla leaf is an example of cytoplasmic streaming.
a) True
b) False
Answer: a
Clarification: Cytoplasmic streaming is the movement of cytoplasm within a plant or animal cell. It helps in symplastic movement. It is commonly seen in the movement of chloroplast in cells of Hydrilla leaf.

2. Bulk flow system occurs as a result of difference in ________
a) Height
b) Side of leaf
c) Pressure
d) Temperature
Answer: c
Clarification: Bulk flow system occurs as a result of difference in pressure. Difference in sides of leaf leads to change in amount of photosynthesis, where lower leaf carries higher amount of photosynthesis than the upper leaf. Difference in height doesn’t have any role to play as xylem vessels take water from lower height to upper height. Difference in temperature leads to change in transpiration rate.

3. The pathway of absorption of water involving system of interconnected protoplasts is _______
a) apoplastic pathway
b) symplastic pathway
c) diffusion
d) pressure flow of hypothesis
Answer: b
Clarification: Symplastic pathway consists of cytoplasm and intercellular movement through plasmodesmata. Apoplastic pathway consists of intercellular spaces and walls of the cells. Diffusion is simply the movement of water from higher concentration gradient and lower concentration gradient. Pressure flow of hypothesis is the mechanism of pathway of translocation of sugars from source to sink.

4. Water loss in its liquid phase from special openings of veins near the tip of grass blades is termed as _________
a) guttation
b) exudation
c) girdling
d) transpiration
Answer: a
Clarification: Guttation is the liquid water loss from special openings of veins of leaves. Exudation is liquid which comes out of the pores or wounds. Girdling is the experiment which proves that translocation of food occurs through phloem. Transpiration is the loss of water from leaf stomata in the form of vapors.

5. Symbiotic association of fungus with the plant root system is known as ________
a) mutualism
b) nodules
c) ureides
d) mycorrhiza
Answer: d
Clarification: Mycorrhiza is the symbiotic association of fungus with the root of the plant. Ureides is a form of nitrogen in which nodules of plants like soyabean export fixed nitrogen. Mutualism is the association where both the partners are interdependent such as plants and animals. Nodules are general associations of legume plants and bacteria.

6. Apoplastic pathway is discontinuous at _______
a) epidermis
b) cortex
c) casparian strips
d) pericycle
Answer: c
Clarification: Apoplastic pathway is carried out as:
Epidermis -> cortex-> endodermis -> pericycle -> xylem.
Casparian strips are a part of endodermis which blocks the Apoplastic pathway. It is made up of suberin.

7. Statement A: Garden hose is an example of positive hydrostatic pressure.
Statement B: Suction through straw is an example of negative hydrostatic pressure.
a) Both the statements are true
b) Both the statements are false
c) Statement A is true but Statement B is false
d) Statement B is true but Statement A is false
Answer: a
Clarification: Positive and negative hydrostatic pressure are types of bulk flow where substances move independently but still all the substances move together. It occurs due to pressure differences between two points.

8. Translocation occurs through _____
a) xylem only
b) phloem only
c) plasmodesmata
d) Vascular tissues
Answer: d
Clarification: Plasmodesmata is the connections through which cytosol movement take place. Xylem is used for water, minerals, organic nitrogen and hormones. Phloem is used for organic and inorganic solutes. Vascular tissues consist of xylem and phloem, together carrying out complete translocation.

9. The extensions of root epidermal cells which increase the surface area for absorption are called as _______
a) casparian strips
b) root hairs
c) sieve plates
d) tracheids
Answer: b
Clarification: Root hairs arise from region of maturation of the root system. They help in increasing area for absorption. Casparian strips are a part of endodermis which blocks the apoplastic pathway. Sieve plates are long columns with holes in the end walls of sieve tube cells of phloem. Tracheids are non-living parts of xylem where water enters directly.

10. The region in the figure given below represents ___________

a) apoplastic pathway
b) symplastic pathway
c) casparian strips
d) plasmodesmata
Answer: a
Clarification: Apoplastic pathway is shown in indigo color which occurs through intercellular spaces and cell walls. Symplastic pathway is through cytoplasms of the cells. Casparian strips is shown in navy blue color. Plasmodesmata is the connecting link between cells which is depicted by grey color.

To practice Botany Objective Questions and Answers,

Biology Multiple Choice Questions on “Higher Plants Photosynthesis – ATP and NADPH-1”.

1. Which of these is not a product of light reaction?
a) Oxygen
b) NADPH
c) ATP
d) NADP
Answer: d
Clarification: The process of photosynthesis has two stages-the light reaction and the dark reaction. The products of the light reaction are oxygen, ATP and NADPH. The light reaction requires light to carry out its reactions.

2. Which of these diffuse out of the chloroplast after the light reaction?
a) ATP
b) Carbon dioxide
c) Oxygen
d) NADPH
Answer: c
Clarification: The process of photosynthesis has two stages-the light reaction and the dark reaction. The products of the light reaction are oxygen, ATP and NADPH. Oxygen diffuses out of the chloroplast.

3. Which of these statements is incorrect regarding the biosynthetic phase of photosynthesis?
a) It depends on carbon dioxide and water
b) It depends on the products of light reaction
c) ATP and NADH are used
d) Sugars are synthesized
Answer: c
Clarification: The biosynthetic phase of photosynthesis depends upon the products of the light reaction, which are namely oxygen, ATP and NADPH. It leads to the synthesis of food, which are sugars.

4. Which of these scientists have contributed to photosynthesis studies?
a) Melvin Calvin
b) Hargovind Khorana
c) Gregor Mendel
d) Anthony Van Leeuwenhoek
Answer: a
Clarification: Melvin Calvin has contributed greatly to photosynthesis studies. The Calvin cycle was named after him. He first identified the compound PGA or 3-phosphoglyceric acid as a product of photosynthesis.

5. Which of these was used by Melvin Calvin for photosynthesis studies?
a) P-35
b) Radioactive C-14
c) C-13
d) Radioactive S-32
Answer: b
Clarification: Melvin Calvin used the radioactive isotope of carbon-12 or C-12, carbon-14 or C-14 in algal photosynthesis studies. This helped in determining the various steps of the Calvin cycle or pathway.

6. Who discovered the first CO₂ fixation product?
a) Anthony Van Leeuwenhoek
b) Robert Hooke
c) Melvin Calvin
d) Gregor Mendel
Answer: c
Clarification: Melvin Calvin has contributed greatly to photosynthesis studies. The Calvin cycle was named after him. He used radioactive C-14 to discover the first CO₂ fixation product of photosynthesis, PGA.

7. Which of these is a 3-carbon organic acid?
a) PGA
b) BTCA
c) Citric acid
d) Acetic acid
Answer: a
Clarification: PGA or 3-phosphoglyceric acid is a 3-carbon organic acid. Citric acid has 6 carbon atoms while acetic acid has 2 carbon atoms. PGA is a product of the carbon dioxide fixation stage of photosynthesis.

8. What is the full form of PGA?
a) 2-phosphoglyceric acid
b) 2-phosphoglutamic acid
c) 3-phosphoglutamic acid
d) 3-phosphoglyceric acid
Answer: d
Clarification: The full form of PGA is 3-phosphoglyceric acid. 3-phosphoglyceric acid is a product of the carbon dioxide fixation stage of photosynthesis. 3-phosphoglyceric acid is a 3-carbon organic acid.

9. How many carbon atoms does OAA contain?
a) 3
b) 2
c) 4
d) 1
Answer: c
Clarification: OAA or oxaloacetic acid is a 4-carbon compound. It is an organic acid. OAA or oxaloacetic acid is the first stable product of carbon dioxide fixation during photosynthesis, in some plants.

10. CO₂ assimilation during photosynthesis is of 3 types. True or false?
a) True
b) False
Answer: b
Clarification: Carbon dioxide assimilation during photosynthesis is of two types depending upon the first stable product of carbon dioxide fixation. The two types are the C₃ pathway and the C₄ pathway.

11. Which is the first product of CO₂ fixation in the C₃ pathway?
a) NADPH
b) OAA
c) ATP
d) PGA
Answer: d
Clarification: Carbon dioxide assimilation during photosynthesis is of two types depending upon the first stable product of carbon dioxide fixation. the first product of CO₂ fixation in the C₃ pathway is PGA.

12. Which is the first product of CO₂ fixation in the C₄ pathway?
a) NADPH
b) PGA
c) OAA
d) ATP
Answer: c
Clarification: Carbon dioxide assimilation during photosynthesis is of two types depending upon the first stable product of carbon dioxide fixation. the first product of CO₂ fixation in the C₄ pathway is OAA.

13. What is the primary acceptor of CO₂ in photosynthesis?
a) ATP
b) PGA
c) RuBP
d) OAA
Answer: c
Clarification: The primary acceptor of carbon dioxide in photosynthesis is RuBP or ribulose bisphosphate. Ribulose bisphosphate is a 5-carbon ketose sugar. It accepts carbon dioxide from the atmosphere.

14. Which of these compounds have 5 carbon atoms?
a) RuBP
b) OAA
c) PGA
d) ATP
Answer: a
Clarification: RuBP or Ribulose bisphosphate is a 5-carbon ketose sugar. It is the primary acceptor of carbon dioxide in photosynthesis. OAA is a 4-carbon organic acid while PGA is a 3-carbon organic acid.

15. How many carbon atoms does the primary acceptor of CO₂ in photosynthesis have?
a) 4
b) 5
c) 3
d) 2
Answer: b
Clarification: RuBP or Ribulose bisphosphate is a 5-carbon ketose sugar. It is the primary acceptor of carbon dioxide in photosynthesis. It accepts carbon dioxide from the atmosphere for the process of photosynthesis.

Botany Viva Questions and Answers on “Growth Regulators in Plants – 2”.

1. Which of the following is a gaseous hormone?
a) Ethylene
b) ABA
c) GA
d) Auxin
Answer: a
Clarification: Ethylene is a volatile gaseous hormone. GA, ABA and Auxin are acidic in nature. GA and Auxin are growth promoters while ABA is a growth inhibitor.

2. ABA is a derivative of adenine purine.
a) True
b) False
Answer: b
Clarification: ABA is a growth inhibitor. It is a derivative of carotenoids. It is functional mainly during stressful conditions. Cytokinin is a growth promoter. It is an adenine derivative (N6-furfurylamino purine). It is responsible for plant growth along with auxin hormone.

3. The hormone responsible for femaleness in cucumbers is ________
a) IAA
b) ABA
c) GA
d) Ethylene
Answer: d
Clarification: Ethylene is the hormone responsible for femaleness in cucumbers. IAA and GA induce parthenocarpy in fruits. ABA is not related to ripening of fruits.

4. Richmond Lang effect is linked to ________
a) Cytokinins
b) ABA
c) GA
d) NAA
Answer: a
Clarification: Richmond Lang effect is related to delay in senescence of mature parts of plants. It is linked to cytokinin hormone. GA and NAA also help in attaining precocious maturity. ABA promotes senescence in stressful conditions.

5. The hormone antagonistic to ABA is_______
a) IAA
b) Ethylene
c) GA
d) Kinetin
Answer: c
Clarification: GA acts antagonistically to ABA. IAA is synthetic auxin. Kinetin delays senescence. Ethylene promotes abscission of older parts.

6. The source of hormone ethylene is________
a) oats
b) ethephon
c) coconut milk
d) urine
Answer: b
Clarification: The source of hormone ethylene is ethephon. Source of auxin is oats. Source of cytokinin is coconut kernel. Auxin was first isolated from human urine.

7. The role of PGRs is a kind of intrinsic control.
a) True
b) False
Answer: a
Clarification: Plant growth is controlled by factors categorized into intrinsic control, genomic control and extrinsic control. Plant growth regulators including both promoters and inhibitors are controlled by hormones and come under intrinsic control. All the environmental factors come under extrinsic control.

8. Which of the following hormone is a stress hormone?
a) Ethylene
b) ABA
c) Auxin
d) GA
Answer: b
Clarification: ABA is a hormone which works in stressful conditions. GA acts antagonistic to ABA. Auxin leads to apical dominance. Ethylene is related to early ripening of fruits.

9. Which of the following hormone is used to induce morphogenesis in plant tissue culture?
a) Cytokinins
b) Ethylene
c) Auxin
d) ABA
Answer: a
Clarification: Cytokinins is used to induce morphogenesis in plant tissue culture. Auxin and cytokinin together in varied amounts carry out root and shoot differentiation. Ethylene leads to early ripening. ABA acts as a stress hormone.

10. The hormone responsible for enhancement of the respiration rate of fruits thereby leading to its early ripening is ________
a) Auxin
b) GA₃
c) Ethylene
d) ABA
Answer: c
Clarification: Ethylene is the hormone responsible for enhancement of the respiration rate of fruits thereby leading to its early ripening. Auxin and GA₃ induces parthenocarpy of fruits. ABA acts as a stress hormone.

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