Category: Class 11 Biology Objective Questions

Zoology Question Papers on “Animal Tissues-4”.

1. What type of tissue is present in the lining of ducts?
a) Connective
b) Neural
c) Muscular
d) Epithelial
Answer: d
Clarification: Epithelial tissue consists of single layer of cells and lines body cavities, ducts and tubes. Connective tissue, muscular tissue and neural tissue are other classifications of animal tissues with different functions.

2. Which of these is not a structural classification of simple epithelium?
a) Columnar
b) Cuboidal
c) Cubical
d) Squamous
Answer: c
Clarification: Based on structure, simple epithelium is classified into three types. These are columnar, cuboidal and squamous. Cubical is not a classification of epithelial tissue.

3. Microvilli is present in the epithelium of _______
a) walls of blood vessels
b) air sacs of lungs
c) proximal convoluted tubule of nephron
d) skin surface
Answer: c
Clarification: Proximal convoluted tubule of nephron in the kidneys contain cuboidal epithelium with microvilli. This helps in absorption. The rest of the options contain squamous epithelium.

4. Which of the following do not contain ciliated epithelium?
a) Gastrointestinal tract
b) Bronchioles
c) Uterus
d) Fallopian tubes
Answer: a
Clarification: Ciliated epithelium present on the inner lining of uterus, fallopian tubes and bronchioles facilitate the movement of particles and mucus in a specific direction. The lining of the gastrointestinal tract contains non-ciliated epithelial tissue.

5. What is the main function of compound epithelium?
a) Secretion
b) Protection
c) Absorption
d) Discharge
Answer: b
Clarification: Compound epithelium is multi – layered and has a minimal role in secretion and absorption. The main function of these cells is to provide protection against stresses – both mechanical and chemical. Glandular epithelium plays a major role in secretion and absorption.

6. Which of the following cellular junctions create a cytoplasmic connection between adjoining cells?
a) Tight junctions
b) Adhering junctions
c) Gap junctions
d) Occluding junctions
Answer: c
Clarification: Gap junctions facilitate cell-to-cell communication by creating cytoplasmic connections for the rapid movement of ions, small molecules and sometimes big molecules. Tight or occluding junctions create intercellular barriers while adhering junctions facilitate intercellular attachment.

7. Which of these is not true about areolar tissue?
a) Macrophages are absent
b) It is a support framework for epithelium
c) It contains mast cells
d) It contains fibroblasts
Answer: a
Clarification: Areolar tissue is a type of loose connective tissue which is present below the skin. It provides a support for epithelium and contains macrophages, mast cells and fibroblasts.

8. Which of these is not a secondary lymphoid organ?
a) Lymph nodes
b) Tonsils
c) Spleen
d) Thymus
Answer: d
Clarification: Thymus and bone marrow are primary lymphoid organs. Lymph nodes, tonsils, and spleen are secondary lymphoid organs.

9. In which of these structures is collagen fibers present in rows between parallel bundles of fibers?
a) Skin
b) Submucosa of digestive tract
c) Tendon
d) Tunica albuginea
Answer: c
Clarification: Collagen fibers are present in parallel bundles in dense regular connective tissues, such as in tendons. Skin, submucosa of digestive tract and tunica albuginea covering the testes have dense irregular connective tissue.

10. Osteocytes are present in spaces called ______
a) lamellae
b) lacunae
c) lacrimal sacs
d) lacteals
Answer: b
Clarification: Osteocytes or bone cells are present in spaces called lacunae. Lamella is a thin membrane, lacrimal sacs are present in the upper end of the nasolacrimal duct, while lacteals are lymphatic vessels connected to the intestines.

11. Skeletal muscles are _______
a) not attached to bones
b) involuntary
c) non-striated
d) striated
Answer: d
Clarification: Skeletal muscles are attached to skeletal bones. They control voluntary actions and are striated. Smooth muscles are non-striated.

12. What type of muscle fiber is shown below?

a) Cardiac
b) Skeletal
c) Smooth
d) Voluntary
Answer: c
Clarification: The diagram shows a fusiform cell. It does not have striations. Hence, it is smooth muscle fiber. It is not a cardiac muscle fiber or skeletal or voluntary muscle fiber as it is not branched and does not have striations.

13. Which of the following is true about neuroglial cells?
a) They act as neurons during stress
b) They conduct impulses to and from neurons
c) They protect and support neurons
d) They are only present in the brain
Answer: c
Clarification: Neuroglial cells help to protect and support neurons. They constitute more than half of the volume of neural tissue. They are not neurons and hence, do not conduct impulses.

14. When a neuron is stimulated, the electrical signal travels along the _______
a) plasma membrane
b) cytoplasm
c) cytoskeleton
d) extracellular matrix
Answer: a
Clarification: The electrical signal of a stimulated neuron travels along the plasma membrane by a series of polarization and depolarization. At the ending of the neuron, the signal is transmitted to the target tissue or the adjacent neuron.

15. What does adipose tissue store?
a) Proteins
b) Fat
c) Glycogen
d) Water
Answer: b
Clarification: Adipose tissue is a classification of loose connective tissue. Excess nutrients are stored as fat in these tissues. It also serves to protect the body from shocks and stresses.

To practice Zoology Question Papers,

Biology Multiple Choice Questions on “Cell – Nucleus and Cytoplasm”.

1. Which among the following is incorrect about nucleus?
a) In plant cells, nucleus lies towards the periphery due to the large nucleus that occupies almost the entire region of the cell
b) Nucleus helps in reproduction and acts as the control centre of the cell
c) Nucleoplasm condenses and group together to form chromosomes
d) Nucleus comprises of nuclear membrane, nuclear pores, nucleolus, nucleoplasm and chromatin
Answer: c
Clarification: In plant cells, nucleus lies towards the periphery due to the large nucleus that occupies almost the entire region of the cell. Nucleus helps in reproduction and acts as the control centre of the cell. Chromatin condenses and group together to form chromosomes. Nucleus comprises of nuclear membrane, nuclear pores, nucleolus, nucleoplasm and chromatin.

2. Which among the following is an incorrect statement about the structure of nucleus?
a) Nuclear membrane is a double layered covering of nucleus which is separated by a perinuclear space
b) Nuclear pores allow the transfer of materials and disrupt the continuity of nuclear membrane
c) Nucleoplasm is also termed as “Karyolymph” and act as site for synthesis of DNA and RNA
d) Nucleolus contains RNA, DNA, histone and non-histone proteins
Answer: d
Clarification: Nuclear membrane is a double layered covering of nucleus which is separated by a perinuclear space. Nuclear pores allow the transfer of materials and disrupt the continuity of nuclear membrane. Nucleoplasm is also termed as “Karyolymph” and act as site for synthesis of DNA and RNA. Chromatin contains RNA, DNA, histone and non – histone proteins.

3. Centrioles are the primary constrictions of chromosomes.
a) True
b) False
Answer: b
Clarification: Chromosomes form when chromatids condense during reproduction. Centromeres are the primary constrictions of chromosomes. Based on the position of centromeres, chromosomes can be classified into acrocentric, metacentric, sub-metacentric and telocentric chromosomes.

4. Which among the following is incorrect about chromosomes?
a) Chromosomes are rod shaped structures that condenses together when the cell is about divide
b) Chromosomes are composed of DNA, RNA and proteins which act as repository for inheritance
c) Kinetochores are disc like structures that are present on the sides of centromeres
d) In acrocentric chromosomes, centromere is present in the end of the chromatids
Answer: d
Clarification: Chromosomes are rod shaped structures that condenses together when the cell is about divide. Chromosomes are composed of DNA, RNA and proteins which act as repository for inheritance. Kinetochores are disc like structures that are present on the sides of centromeres. In telocentric chromosomes, centromere is present in the end of the chromatids.

5. Cells can have either one or more nuclei and sometimes might not even nucleus.
a) True
b) False
Answer: b
Clarification: Cells can have either one or more nuclei and sometimes might not even nucleus. Based on the number of nuclei present cells are classified as anucleate, uninucleate and multi-nucleate.

6. Which among the following is incorrect about RBCs?
a) RBCs are anucleate because this allows them contain more oxygen and therefore carry more oxygen
b) Immature RBCs do contain nucleus which lets them to reproduce but in the later stage of their life they become devoid of nucleus
c) RBCs contain all other organelles like mitochondria, Golgi apparatus and SER etc
d) Due to lack of nucleus, they don’t get involved in the protein synthesis
Answer: c
Clarification: RBCs are anucleate because this allows them contain more oxygen and therefore carry more oxygen. RBCs are anucleate because this allows them contain more oxygen and therefore carry more oxygen. RBCs lack mitochondria, Golgi apparatus and SER etc. Due to lack of nucleus, they don’t get involved in the protein synthesis.

7. What is the difference between eukaryotic and prokaryotic cell when it comes to nucleus?
a) Eukaryotic cell contains nucleus whereas prokaryotic cell don’t
b) Eukaryotic nucleus contains genetic material in them whereas prokaryotic nucleus don’t
c) Eukaryotic cell contains membrane bound nucleus whereas prokaryotic cell don’t
d) Eukaryotic cells contain both DNA and RNA whereas prokaryotic cell has only RNA
Answer: c
Clarification: Eukaryotic cell contains membrane bound nucleus whereas prokaryotic cell don’t. Both eukaryotic and prokaryotic and eukaryotic cells contain nucleus (or nucleolus) which contains genetic material in them i.e. both DNA and RNA in them.

8. Cytoplasm without cell organelles is termed as _______
a) Cytosol
b) Cyclosis
c) Lymph
d) Blood
Answer: a
Clarification: The fluid inside the cell enclosed by plasma membrane. It is little viscous and comprises of 80% water. Cytoplasm without cell organelles is termed as Cytosol. Cytosol is not static and movement of cytoplasm is termed as cyclosis

9. Which among the following statements are incorrect?
a) PH, temperature, viscosity, hormones and light are the factors effecting cyclosis
b) Higher the viscosity more is the rate of cyclosis
c) Cytoplasm plays the vital role in respiration and contains dissolved nutrients
d) Cytoplasm controls the shape of the cell and dissolves waste product
Answer: b
Clarification: pH, temperature, viscosity, hormones and light are the factors effecting cyclosis. Lower the viscosity more is the rate of cyclosis. Cytoplasm plays the vital role in respiration and contains dissolved nutrients. Cytoplasm controls the shape of the cell and dissolves waste product.

10. Which among the following is not a part of endomembrane system?
a) Endoplasmic reticulum
b) Mitochondria
c) Vacuoles
d) Golgi apparatus
Answer: b
Clarification: Endomembrane system comprises of vacuoles, endoplasmic reticulum, endosomes, nuclear membrane, vesicles, lysosomes and plasma membrane. They act as a single functional and developing unit of the cell.

Biology Multiple Choice Questions on “Biomacromolecules – 1”.

1. What is the unit of measurement of weight of biomacromolecules?
a) Nanometer
b) Farad
c) Angstrom
d) Dalton
Answer: d
Clarification: The molecular weight of biomacromolecules such as nucleic acids, proteins and carbohydrates is measured in Daltons. Angstrom and nanometer are units of length while farad is a unit of capacitance.

2. What is the approximate weight of compounds found in acid soluble pool of grinded tissue?
a) 1,000 – 10,000 Da
b) 2 – 30 Da
c) 18 – 800 Da
d) 6,000 – 50,000 Da
Answer: c
Clarification: When tissue is grinded in trichloroacetic acid and strained, it separates into an acid soluble pool and an acid insoluble pool. The acid soluble pool contains compounds whose approximate molecular weight is between 18 to 800 Da.

3. Which of these compounds is not present in the acid insoluble fraction of homogenized tissue?
a) Proteins
b) Fats
c) Vitamins
d) Nucleic acids
Answer: c
Clarification: The acid insoluble pool or fraction of the homogenized plant or animal tissue contains proteins, lipids, carbohydrates and nucleic acids. These molecules are also known as biomolecules. Vitamins are not present.

4. Which of these compounds do not have a molecular weight greater than 10,000 Da?
a) Lipids
b) Proteins
c) Polysaccharides
d) Nucleic acids
Answer: a
Clarification: The acid insoluble layer of homogenized, strained tissue consists of proteins, nucleic acids, lipids and polysaccharides. Out of these biomacromolecules, lipids have a molecular weight lesser than 10,000 Da.

5. Micro-molecules of the tissue are also known as ______
a) bio compounds
b) biomolecules
c) biomacromolecules
d) nanoparticles
Answer: b
Clarification: Micro-molecules are those molecules that have a molecular weight less than 1000 Da or from 1 to 1000 Da. They are also known as biomolecules. They contain vitamins and minerals that are required by the body.

6. What is the maximum weight of biomolecules?
a) 800 Da
b) 10,000 Da
c) 1000 Da
d) 5000 Da
Answer: c
Clarification: Biomolecules or micro-molecules have an approximate molecular weight between 1 to 1000 Da. Thus, 1000 Da is the maximum weight. Biomacromolecules have a molecular weight greater than 10,000 Da.

7. Which of these substances is not polymeric?
a) Lipids
b) Nucleic acids
c) Proteins
d) Polysaccharides
Answer: a
Clarification: When tissue matter is homogenized and strained, it separates into an acid soluble pool and an acid insoluble pool. The acid insoluble pool contains proteins, nucleic acids, polysaccharides and lipids. Out of these, only lipids are not polymeric.

8. The molecular weight of lipids does not exceed _____
a) 5000 Da
b) 1000 Da
c) 10,000 Da
d) 800 Da
Answer: d
Clarification: Proteins, nucleic acids and polysaccharides are polymeric substances and are biomacromolecules whose approximate molecular weight is greater than 10,000 Da. Lipids are not polymeric and the weight does not exceed 800 Da.

9. When tissue is homogenized, the disrupted cell membrane separates in the form of _____
a) solid aggregates
b) lipoprotein complexes
c) vesicles
d) lipopolysaccharides
Answer: c
Clarification: The cell membrane is predominantly composed of lipids, which form a bilayer around the cytosol and the cell organelles. When the cell is disrupted, the lipid bilayer separates and forms vesicles.

10. Lipids are not macromolecules as their weight does not exceed 800 Da. True or false?
a) True
b) False
Answer: b
Clarification: Unlike macromolecules such as proteins, polysaccharides and nucleic acids which have a molecular weight greater than 10,000 Da, the weight of lipids does not exceed 800 Da. However, lipids are not polymers but are considered macromolecules.

11. What percentage of the total cellular mass is water?
a) 5 – 7
b) 50 – 60
c) 10 – 15
d) 70 – 90
Answer: d
Clarification: Water is the main component of the cytosol. Hence, the cell contains 70% to 90% water. Various ions, molecules and compounds required for the functioning of the cell are dissolved in the water.

12. What percentage of the total cellular mass is nucleic acids?
a) 1 – 2
b) 50 – 60
c) 5 – 7
d) 20 – 30
Answer: c
Clarification: Nucleic acids such as deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) make up the genetic material of the cell. DNA is present inside the nucleus while RNA is present both in the nucleus and cytoplasm. It makes up 5 – 7% of the total cellular mass.

13. 10 – 15% of the total cellular mass is ______
a) nucleic acids
b) water
c) proteins
d) carbohydrates
Answer: c
Clarification: 10 – 15% of the total cellular mass is taken up by proteins. Proteins are synthesized in the cytosol by the information present in the nucleic acids. Nucleic acids are the genetic material of the cell.

14. What percentage of the total cellular mass is carbohydrates?
a) 3
b) 2
c) 1
d) 10
Answer: a
Clarification: 3% of the total cellular mass is taken up by carbohydrates. 2% is taken up by lipids, 1% is taken up by various ions and 10% of the total cellular mass is taken up by the various proteins present in the cell.

15. 2% of the total cellular mass is _____
a) proteins
b) lipids
c) ions
d) nucleic acids
Answer: b
Clarification: 2% of the total cellular mass is taken up by lipids. In the cell, lipids are predominantly found in the cell membrane and nuclear membrane, where they are present in the form of a phospholipid bilayer.

Biology Exam Questions for Medical Entrance Exams on “Cell Cycle and Division – Meiosis-2”.

1. What is the enzyme involved in crossing over?
a) Isomerase
b) Invertase
c) Transferase
d) Recombinase
Answer: d
Clarification: Crossing over or recombination takes place during the pachytene stage of prophase I. Crossing over is an enzyme-mediated phenomenon and the enzyme involved in this process is recombinase.

2. During which stage does the synaptonemal complex dissolve?
a) Leptotene
b) Pachytene
c) Diplotene
d) Zygotene
Answer: c
Clarification: The synaptonemal complex is formed in the second stage of prophase I, that is, zygotene stage. After crossing over takes place during pachytene stage, the complex is dissolved during the diplotene stage.

3. What shape is the chiasmata?
a) S-shaped
b) Y-shaped
c) X-shaped
d) L-shaped
Answer: c
Clarification: The chiasmata is an X-shaped structure formed by the bivalents or the tetrads during prophase I of meiosis I. It occurs due to the tendency of the homologous chromosomes of a tetrad to move away from each other.

4. At what stage can one visualize chiasmata?
a) Diplotene
b) Pachytene
c) Leptotene
d) Zygotene
Answer: a
Clarification: Chiasmata is an X-shaped structure formed by the tetrad. It occurs due to the tendency of the homologous chromosomes of a tetrad to move away from each other except at the center. It occurs in the diplotene stage of prophase I.

5. During which stage does assembly of meiotic spindle take place?
a) Pachytene
b) Diakinesis
c) Metaphase I
d) Diplotene
Answer: b
Clarification: Diakinesis is the last stage of prophase I of meiosis I during which the assembly of spindle fibers takes place. Diakinesis is also characterized by the disappearance of the X-shape of chiasmata.

6. Identify the phase of meiosis.

a) Anaphase II
b) Telophase II
c) Anaphase I
d) Telophase I
Answer: c
Clarification: From the given diagram, we can observe that the chromosomes are moving towards the poles from the center. Hence, it is anaphase. Since it results in the separation of the tetrad, it is anaphase I.

7. Which of these is true about anaphase I?
a) Sister chromatids remain attached at the centromeres
b) Bivalent is unequally separated
c) Homologous chromosomes remain together
d) It takes place before diakinesis
Answer: a
Clarification: During anaphase I of meiosis, the homologous chromosomes are separated and the bivalent is hence, equally divided. It takes place after diakinesis, which is a part of prophase I. Sister chromatids are not separated.

8. Which of these stages is characterized by the disappearance of the nucleolus?
a) Zygotene
b) Pachytene
c) Diplotene
d) Diakinesis
Answer: d
Clarification: The disappearance of the nucleolus takes place during the last stage of prophase I, that is, diakinesis. This stage is also characterized by the disintegration of the nuclear membrane. It depicts transition to metaphase I.

9. During which stage of meiosis do the sister chromatids separate?
a) Telophase I
b) Anaphase I
c) Anaphase II
d) Telophase II
Answer: c
Clarification: During anaphase I, the tetrad is divided and hence the homologous chromosomes are separated. However, the sister chromatids remain attached to each other. During anaphase II, the sister chromatids are separated.

10. Nuclear membrane does not appear at the end of anaphase I. True or false?
a) True
b) False
Answer: b
Clarification: The nuclear membrane reappears at the end of anaphase I, during telophase I. Telophase I is also characterized by the appearance of the nucleolus, which was disintegrated during diakinesis.

11. Which of the following statements is false regarding interkinesis?
a) It is mostly short lived
b) It is followed by prophase II
c) It occurs after telophase I
d) Replication takes place
Answer: d
Clarification: Interkinesis is the period between meiosis I and meiosis II. It is mostly short lived and occurs after telophase I. It is followed by prophase II. However, no DNA replication takes place during this period.

12. How do chromatids reach the poles of the cells during anaphase?
a) Action of centromeres
b) Disintegration of spindle fibers
c) Shortening of microtubules
d) Movement of arms of chromatids
Answer: c
Clarification: During anaphase, the chromatids are separated and start moving towards the poles from the metaphase plate. This occurs by the shortening of the microtubules which pulls the chromatids towards the poles.

13. The stage preceding the stage during which crossing over takes place is ______
a) diplotene
b) pachytene
c) zygotene
d) leptotene
Answer: c
Clarification: Crossing over and recombination takes place during the pachytene stage of prophase I. The stage preceding this is the zygotene stage which is characterized by the formation of the synaptonemal complex.

14. Which of these statements is true about meiosis I?
a) Crossing over leads to genetic variability
b) Diplotene is short lived in vertebrates
c) Diakinesis is followed by cytokinesis
d) Chiasmata formation occurs during metaphase I
Answer: a
Clarification: Diplotene can last for years in some vertebrates, hence it is not always short lived. Diakinesis is followed by metaphase I. Chiasmata is formed during diplotene. Crossing over leads to genetic variation.

15. Identify the phase of meiosis.

a) Metaphase II
b) Metaphase I
c) Prophase II
d) Prophase I
Answer: b
Clarification: In the diagram, it is observed that the bivalents or the tetrads are aligned towards the center of the cell, that is, on the metaphase plate. Hence, the given stage is identified to be metaphase I.

To practice Biology Exam Questions for Medical Entrance Exams,

Biology MCQs for NEET Exam on “Photosynthesis Basics – 2”.

1. The following diagram represents ______

a) Joseph Priestly experiment
b) Gregor Mendel experiment
c) Engelmann experiment
d) Linnaeus experiment
Answer: a
Clarification: This shows the Joseph Priestly experiment. Here, (a) and (b) shows that when a mouse and a candle is placed in a jar without air, the mouse dies. Whereas, (c) and (d) shows that when a mint plant is placed along with the mouse and candle, we can see that the mouse is still alive. The plant restores the oxygen inside the jar.

2. During which year, Joseph Priestley discovered O₂?
a) 1774
b) 1770
c) 1884
d) 1880
Answer: a
Clarification: Joseph Priestley discovered O₂ in 1774. He found the presence of oxygen during his experiment. In a jar containing a mouse, a candle and a mint plant, he found out that the mouse was alive and the candle was lit up. This showed that the mint plant gave oxygen to the enclosed jar.

3. Photosynthesis is the basis of life on earth because ______
a) It is the main source of all food on earth
b) It helps in the release of CO₂ into the atmosphere
c) It produces new offsprings
d) It gives no energy to plants
Answer: a
Clarification: Photosynthesis is the basis of life on earth because it is the main source of all food on earth. It is also responsible for the release of oxygen into the atmosphere. It does not produce new offsprings but gives energy or glucose to the plants in the form of starch.

4. Other than CO₂ and light, which is used as the raw material for photosynthesis?
a) O₂
b) CO₂
c) H₂O
d) MnO₂
Answer: c
Clarification: The raw materials of photosynthesis are carbon dioxide and water in the presence of sunlight. And its final products are glucose, water, and oxygen. These substances are the most abundant materials on earth and provide equivalent oxygen to atmosphere.

5. Among the following, which compound does not play an important role in photosynthesis?
a) Xanthophyll
b) Anthocyanin
c) Chlorophyll
d) Phycoerythrin
Answer: b
Clarification: Anthocyanin does not play an important role in photosynthesis whereas the others have an important role. Anthocyanin main role is to provide blue, red and purple color to the plants. It also protects the plants from high temperatures and abiotic stresses.

6. What do we call the organism that does photosynthesis but does not release oxygen?
a) Green sulfur bacterium
b) Blue-green algae
c) Green algae
d) Green plants
Answer: a
Clarification: Green sulfur bacterium does photosynthesis but does not release oxygen. They are anoxygenic. They use H₂S as a substitute for water and utilize sulfide ions to form sulfur and water. No oxygen is formed.

7. In photosynthesis, the carbon dioxide is oxidized and water is reduced.
a) True
b) False
Answer: b
Clarification: It is a wrong statement. Here in photosynthesis, the carbon dioxide is reduced and water is oxidized. Carbon dioxide is reduced to glucose whereas water is oxidized to oxygen.

8. Who found out that oxygen evolved from water in photosynthesis?
a) T. W. Engelmann
b) C. Van Neil
c) R. Hill
d) Ruben and Kamen
Answer: c
Clarification: R. Hill found out that oxygen evolved from water in photosynthesis. It was believed that oxygen came from carbon dioxide. Later, Hill’s reaction showed that oxygen was produced from water.

9. What were the isotopes used, to research about photosynthesis?
a) ¹¹C and ³²P
b) ¹⁵C and ³⁵Cl
c) ¹³C and ¹⁴N
d) ¹⁴C and ¹⁸O
Answer: d
Clarification: ¹⁴C and ¹⁸O were the isotopes used to research about photosynthesis. A plant undergoing photosynthesis produces more ¹⁸O than normal oxygen. Also, ¹⁴C was used to estimate the presence of carbon atoms in the photosynthesis process.

10. Why is light energy used in photosynthesis?
a) Reduction of H₂O
b) Reduction of CO₂
c) Activation of chlorophyll
d) Oxidation of C₆H₁₂O₆
Answer: c
Clarification: Light energy is mainly used in photosynthesis for activation of chlorophyll. Chlorophyll is in an inactive state. It becomes active only in the presence of sunlight. These rays fall on chloroplast which in turn activates the chlorophyll.

11. During photosynthesis, which light is least effective?
a) Greenlight
b) Sunlight
c) Yellow light
d) Blue light
Answer: a
Clarification: Greenlight is the least effective among the following. Greenlight is reflected by green leaves, so cannot be absorbed. But blue light gives maximum absorption peak of chlorophyll and is most effective.

To practice Biology MCQs for NEET Exam,

Botany Problems on “Respiratory Quotient”.

1. Is it possible to make calculations of the net gain of ATP?
a) Not possible
b) Possible only theoretically
c) Possible only in reality
d) Sometimes possible and sometimes not
Answer: b
Clarification: Yes, it is possible to make calculations of the net gain of the ATP that is formed in the respiratory pathway by the oxidation of some suitable respiratory substrates but this can remain only a theoretical exercise as the real amount of energy released in the cell may vary.

2. Which of the following is an assumption of the respiratory balance sheet?
a) Respiration is a sequential pathway
b) Respiration does not exist
c) Energy cannot be calculated in a respiratory pathway
d) Energy is always lost in the form of heat in respiration
Answer: a
Clarification: One of the assumptions made in the respiratory balance sheet is that there is a sequential, orderly pathway functioning, with one substrate forming the next and with glycolysis, TCA cycle and ETS pathway following one after another.

3. Which of the following is not an assumption of the respiratory balance sheet?
a) NADH synthesised in glycolysis is transferred into mitochondria
b) None of the intermediates is used to synthesise other compounds
c) Respiration is a sequential pathway
d) Energy can never be stored
Answer: d
Clarification: Certain assumptions of the respiratory balance sheet include that none of the intermediates in the pathway are utilised to synthesise any other compound. Respiration is a sequential pathway and NADH synthesised in glycolysis is transferred into the mitochondria and undergoes oxidative phosphorylation.

4. All carbohydrates except for glucose can be respired in a respiratory pathway.
a) True
b) False
Answer: b
Clarification: In a respiratory pathway, only glucose is being respired, no other alternative substrates are entering in the pathway at any of the intermediary stages.

5. Do all the respiratory pathways work simultaneously?
a) No, not at all
b) They take place one after the other
c) Yes, they work simultaneously
d) Sometimes they work independently
Answer: c
Clarification: The assumptions made in the respiratory balance sheet are not valid for the living system. All pathways work simultaneously and do not take place one after another.

6. When is the ATP utilised?
a) It is utilised as and when needed
b) It is never utilised
c) It is only in the stored form
d) Only when the cell is about to replicate
Answer: a
Clarification: ATP is utilised as and when needed. Substrates enter the pathway and are withdrawn from it as and when necessary. Enzymatic rates in these pathways are controlled by multiple means.

7. How many ATP molecules are gained during aerobic respiration?
a) 2 ATP
b) 10 ATP
c) 35 ATP
d) 38 ATP
Answer: d
Clarification: Aerobic respiration involves the complete oxidation of glucose. There can be a net gain of 38 ATP molecules during aerobic respiration of one molecule of glucose.

8. How many ATP molecules are gained during fermentation?
a) 8 ATP
b) 2 ATP
c) 10 ATP
d) 4 ATP
Answer: b
Clarification: In fermentation, there is a net gain of only two molecules of ATP for each molecule of glucose degraded to pyruvic acid whereas many more molecules of ATP are generated under aerobic conditions.

9. What is the speed of oxidation of NADH in case of fermentation?
a) Vigorous
b) Very slow
c) Slow
d) Fast
Answer: c
Clarification: NADH is oxidised to NAD⁺ rather slowly in fermentation, however, the reaction is very vigorous in the case of aerobic respiration. The reducing agent in fermentation is NADH + H⁺.

10. Fermentation accounts for the complete breakdown of glucose and sucrose.
a) True
b) False
Answer: b
Clarification: Fermentation accounts for only a partial breakdown of glucose whereas in aerobic respiration it is completely degraded to CO₂ and H₂O.

11. What is the full form of RQ?
a) Respiratory Quotient
b) Reservatory Quotient
c) Reservation Q-value
d) Reservatory Q-value
Answer: a
Clarification: RQ stands for Respiratory Quotient. It is the ratio of the volume of CO₂ evolved to the volume of O₂ consumed in respiration. It is also known as the respiratory ratio.

12. On which of the following does the respiratory quotient depend?
a) The respiratory concentration of Oxygen
b) The respiratory substrate used during respiration
c) The volume of Carbon-dioxide evolved
d) Energy evolved during respiration
Answer: b
Clarification: The respiratory quotient depends upon the type of respiratory substrate used during respiration. In living organisms, respiratory substrates are often more than one.

13. What is the value of RQ in carbohydrates?
a) 0.7
b) 0.3
c) 1
d) 10
Answer: c
Clarification: When carbohydrates are used as substrates and are completely oxidised, the RQ will be 1, because equal amounts of CO₂ and O₂ are evolved and consumed respectively.

14. What is the RQ value for tripalmitin?
a) 0.9
b) 1
c) 0.3
d) 0.7
Answer: d
Clarification: When fats are used in respiration, the RQ is less than 1. For a fatty acid, tripalmitin, the ratio of the volume of carbon dioxide evolved to the volume of oxygen evolved is 0.7.

15. What is the respiratory quotient for organic acids?
a) More than 1
b) Less than zero
c) Zero
d) Less than one but greater than Zero
Answer: a
Clarification: Organic acids have R.Q value more than one. But when proteins are respiratory substrates the ratio would be about 0.9. Pure proteins or fats are never used as respiratory substrates.

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