Category: Class 11 Biology Objective Questions

Biology Multiple Choice Questions on “Biological Classification – Viruses, Viroids and Lichens – 1”.

1. Viruses are living organisms.
a) True
b) False
Answer: b
Clarification: Viruses are non-living organisms. They don’t have cell. They don’t reproduce or perform any metabolic activities when they are outside a living host. When they are inside a living host they do reproduce and multiply in numbers.

2. Viruses in animals contain both RNA and DNA.
a) True
b) False
Answer: a
Clarification: Viruses at any cost don’t contain both RNA and DNA. Animal viruses contain either single/double stranded ribonucleic acid or double stranded deoxy ribonucleic acid.

3. Viruses that infect bacterium are called as _________
a) Bacteriophages
b) Viral bacterium
c) Bacteiocapsid
d) Bacteriomycin
Answer: a
Clarification: Viruses are smaller when compared to bacterium. Viruses can infect bacterium are called bacteriophages. Bacteriophages contain double stranded DNA (Deoxy ribonucleic acid).

4. Viruses that infect plants have ________
a) single stranded RNA
b) double stranded RNA
c) single stranded DNA
d) double stranded DNA
Answer: a
Clarification: Viruses that infect plants called as plant viruses have single stranded RNA. Animal viruses contain a single/ double stranded RNA or a double stranded DNA. Bacteriophages have double stranded DNA.

5. The word “Virus” means ______
a) Venom
b) Proliferate
c) Change
d) Tremendous
Answer: a
Clarification: The word “Virus” refers to venom or poisonous. It was first termed by a Dutch microbiologist named Martinus Beijerinck in 20^th century. Dmitri Ivanowsky discovered viruses for the first time.

6. Why are viruses not included in any of the five kingdoms?
a) There are already more than thousands of organisms in the five kingdoms and hence, no space to include viruses
b) Viruses are not living organisms
c) Viruses reproduce rapidly which is in fact weird and therefore they are not classified under any of the five kingdoms
d) Viruses are so small that they can’t be studied
Answer: b
Clarification: Unlike organisms in the other five kingdoms which are living, viruses are non-living organisms. They don’t even have basic unit of life i.e. cell. Hence, they are not categorized in any of the kingdoms.

7. Which among the following are incorrect about Viruses?
a) Viruses are acellular
b) Viruses are smaller than bacterium
c) Viruses can perform all of their metabolic activities except reproduction when outside a living host
d) Viruses are non-living organisms
Answer: c
Clarification: Viruses can’t perform any of the metabolic activities when outside a living host. So, they are non-living organisms. Viruses don’t even consist of a cell and so acellular. They are in fact smaller than that of a bacterium and can even infect them.

8. Viruses contain sheath made of ______
a) Nucleic acids
b) Proteins
c) Saccharides
d) Chitin
Answer: b
Clarification: Viruses don’t contain cell and instead have genetic material made of nucleic acids and a protein sheath covering it which is made of proteins. This protein sheath is called capsid and is made of basic units called as capsomeres.

9. Who proved that viruses are crystalline like structures?
a) W M Stanley
b) Ivanowsky
c) M W Beijerinek
d) Lavoisier
Answer: b
Clarification: Ivanowsky discovered viruses as micro-organisms on tobacco plant and are smaller than bacterium. Later M W Beijerinek termed them as “Viruses” which means venom or poison. W M Stanley for the first time proved that viruses are crystalline like structures and these crystals are made of protein rich sheaths.

10. Viruses are an example of ________
a) Obligate parasites
b) Facultative parasites
c) Commensalism
d) Ectoparasites
Answer: a
Clarification: Viruses are an example of obligate parasites. Viruses can’t perform any of their metabolic activities when they are outside a living host. As soon as they enter a living host they replicate and perform their metabolic activities. Therefore, they are an example of obligate parasites.

Zoology Questions for Entrance Exams on “Classification of Animal Kingdom into Different Phylum-3”.

1. Which among the following is incorrect about Arthropoda?
a) This is the second largest phylum of Animalia Kingdom
b) They have jointed legs due to which they are named Arthropoda
c) Their jointed legs help them in fast mobility
d) Their body is bilaterally symmetrical
Answer: a
Clarification: Arthropoda is the second largest phylum of Animalia Kingdom. They have jointed legs due to which they are named Arthropoda. Their jointed legs help them in fast mobility. Their body is bilaterally symmetrical.

2. Which among the following statements is incorrect about Arthropoda?
a) Their Exoskeleton is made of chitin which helps them from extreme conditions
b) They are triploblastic, segmented and hemocoelomate animals
c) Some of these animals are dioecious and others are monoecious
d) Internal fertilization is seen in terrestrial animals and external fertilization is noticed in aquatic animals
Answer: c
Clarification: Arthropoda are triploblastic, segmented and hemocoelomate animals. Their Exoskeleton is made of chitin which helps them from extreme conditions. They are dioecious and internal fertilization is seen in terrestrial arthropods whereas external fertilization is noticed in aquatic arthropods.

3. Which among the following is incorrect about reproduction in Arthropoda?
a) They are dioecious
b) Internal fertilization takes place in the case of terrestrial arthropods
c) These are mostly viviparous organisms
d) Development of embryo is either direct or indirect
Answer: c
Clarification: Arthropods are dioecious animals. In most of the terrestrial arthropods, internal fertilization occurs whereas in the case of aquatic arthropods external fertilization occurs. Development of Embryo is either direct or indirect. These are mostly oviparous.

4. Which among the following is not correct about Arthropods?
a) Their body consists of three parts, namely, head, thorax and abdomen
b) Their respiratory organs can be either lungs or gills
c) Their digestive system is complete with mouth, esophagus, intestines and rectum
d) They have a heart and blood vessels to supply blood to the organs of the body
Answer: d
Clarification: Arthropods consist of three parts, namely, head, thorax and abdomen. Their respiratory organs can be either lungs or gills. Their digestive system is complete with mouth, esophagus, intestines and rectum. Their circulatory system is of open type i.e. they don’t have either heart or blood vessels to supply blood to the organs of the body.

5. Ganglia fuse to form brain in Arthropods.
a) True
b) False
Answer: a
Clarification: Ganglia fuse to form brain in Arthropods. Ladder like nervous system is present in these organisms. Paired ventral nerve cord run through different segments of the body. Paired Ganglia is noticed I each segment.

6. Which among the following is incorrect about Annelids?
a) The name Annelids is derived from the word “Annulus” which means small ring like structure
b) Some of these organisms are dioecious while few others are monoecious
c) The level of organization in these organisms is organ level of organization
d) The circulatory system is of open type
Answer: d
Clarification: The name Annelids is derived from the word “Annulus” which means small ring like structure. Some of these organisms are dioecious while few others are monoecious. The level of organization in these organisms is organ level of organization. The circulatory system is of closed type.

7. Arthropods excrete through ___________
a) Malpighian tubules
b) Pores
c) Nephridia
d) Kidneys
Answer: a
Clarification: Arthropods excrete through malpighian tubules. These are usually found in the posterior areas of arthropods’ alimentary canal. The structure of malpighian tubules includes a single layer of epithelial cells.

8. Which among the following is incorrect about nervous system in Annelids?
a) Each segment has ganglia that help in the muscular movements
b) They have two ventral nerve chords throughout the body
c) Specialized sensory receptors to help in sense of touch and light
d) The pigmented photo receptors are called Oceli
Answer: d
Clarification: Annelids have ganglia in each segment that help in the muscular movements. They have two ventral nerve chords throughout the body. Specialized sensory receptors are present to help in sense of touch and light. Pigmented photo receptors called Oceli are present in Annelids.

9. Which among the following is incorrect about nervous system in Nematodes?
a) Nerve ring made of four ganglia serves as brain
b) Nerve chords are present on the dorsal and ventral side of their body
c) Dorsal nerves act as sensory nerves of the body
d) Ventral nerves act as both motor controllers and sensory nerves of the body
Answer: c
Clarification: Nerve ring made of four ganglia serves as brain. Nerve chords are present on the dorsal and ventral side of their body. Dorsal nerves act as motor nerves of the body. Ventral nerves act as both motor controllers and sensory nerves of the body.

10. Which among the following is incorrect?
a) Nereis is a monoecious and Pheretima are dioecious
b) Annelids have a complete digestive system with Pharynx, Esophagus, Stomach and Intestines
c) Annelids possess heart and blood vessels
d) Locusta is one of the sociable Arthropods
Answer: a
Clarification: Nereis is a dioecious and Pheretima are monoecious. Annelids have a complete digestive system with Pharynx, Esophagus, Stomach and Intestines. Annelids possess heart and blood vessels i.e. they have a closed circulatory system. Locusta is one of the sociable Arthropods.

To practice Zoology Questions for Entrance Exams,

Botany Question Papers on “Flowering Plants Anatomy – Secondary Growth of a Plant”.

1. A monocot can’t show secondary growth whereas dicot exhibit secondary growth.
a) True
b) False
Answer: a
Clarification: Secondary growth refers to the girthwise growth. Lateral meristematic tissues are responsible for secondary growth. A monocot can’t show secondary growth whereas dicot exhibit secondary growth.

2. Secondary growth is due to _______
a) Cambium
b) Apical meristem
c) Intercalary meristem
d) Parenchyma
Answer: a
Clarification: Secondary growth is due to lateral meristematic tissues i.e. cambium. Cambium tissues are primarily of two kinds, namely, vascular cambium and cork cambium. Vascular cambium is responsible for the formation of secondary growth in vascular bundles and cork cambium is responsible for replacing the broken epidermis.

3. Which among the following is incorrect about vascular cambium?
a) It exists as a layer in between primary xylem and primary phloem
b) Intrafascicular cambium is formed when cambium cells are in between the primary xylem and phloem
c) Interfascicular cambium cells are medullary cells that adjoin intrafascicular cambium
d) A cambial ring is formed in an intrafascicular cambium
Answer: d
Clarification: It exists as a layer in between primary xylem and primary phloem. Intrafascicular cambium is formed when cambium cells are in between the primary xylem and phloem. Interfascicular cambium cells are medullary cells that adjoin intrafascicular cambium. A cambial ring is formed when interfasicular cambium cells connect intrafascicular cambium cells.

4. Which among the following is not correct about vascular cambium?
a) Cells on the outer side of cambial ring differentiate into secondary phloem
b) Cells on the inner side of cambial ring differentiate into secondary xylem
c) Amount of the secondary phloem produced is more than that of secondary xylem
d) Vascular cambium is an example of Meristematic tissue
Answer: c
Clarification: Cells on the outer side of cambial ring differentiate into secondary phloem. Cells on the inner side of cambial ring differentiate into secondary xylem. Amount of the secondary phloem produced is less than that of secondary xylem. Vascular cambium is an example of Meristematic tissue.

5. A layer of Meristematic tissue that develops around the cortex region is called cork cambium.
a) True
b) False
Answer: a
Clarification: A layer of Meristematic tissue that develops around the cortex region is called cork cambium. Cork cambium replaces the broken epidermis due to secondary growth of xylem and phloem.

6. Which among the following is incorrect about cork cambium?
a) Cork cambium helps in the replacement of the broken epidermis during the secondary growth
b) Cells on the outer side of the cork cambium differentiates to form cork
c) Cells on the inner side of the cork cambium differentiates to form secondary cortex
d) Cork is also known as Phelloderm
Answer: d
Clarification: Cork cambium helps in the replacement of the broken epidermis during the secondary growth. Cells on the outer side of cork cambium differentiate to form cork. Cells on the inner side of the cork cambium differentiate to form secondary cortex. Cork is also known as Phellem.

7. Secondary cortex is also called as _________
a) Phellem
b) Phelloderm
c) Secondary xylem
d) Secondary phloem
Answer: a
Clarification: Cells on the outer edge of the cambium grow to form the cork which is also known as Phellem. Cells on the inner edge of the cambium grow to form the secondary cortex which is also known as Phelloderm.

8. Which among the following describes bark?
a) Phloem and xylem
b) Epidermis and parenchymatic cells
c) Everything outside the vascular cambium including the secondary phloem
d) Pith
Answer: c
Clarification: A bark is everything outside the vascular cambium including the secondary phloem. The tissues in a bark comprise of secondary phloem and peridermis (secondary cortex, cork cambium and cork).

9. The wood that grows in the winter due to inactive cambium is called as _______
a) Early wood
b) Heart wood
c) Sapwood
d) Autumn wood
Answer: d
Clarification: Cambium is inactive in winter and forms fewer xylary elements that have narrow vessels and this wood has higher density and is darker than that of the early wood. This wood is called Autumn wood.

10. The region in the secondary phloem that comprises of dead elements and protected by lignified walls is called as _____
a) Early wood
b) Heart wood
c) Sap wood
d) Late wood
Answer: b
Clarification: The region in the secondary phloem that comprises of dead elements and protected by lignified walls is called Heart wood. Heart wood doesn’t conduct water but instead provides mechanical support.

To practice Botany Question Papers,

Zoology Online Quiz on “Animals Structural Organisations – Frogs-2”.

1. Which of these organs secrete bile?
a) Kidney
b) Spleen
c) Gall bladder
d) Liver
Answer: d
Clarification: The liver is the organ responsible for the secretion of bile. The secreted bile is stored in the gall bladder. Bile is a greenish-yellow fluid that acts as an emulsifying agent for the catabolic breakdown of fats.

2. Where is bile stored in the body of frog?
a) Pancreas
b) Liver
c) Gall bladder
d) Bidder’s canal
Answer: c
Clarification: Bile is stored in the gall bladder of the frog after it has been secreted by the liver. Bile is a greenish-yellow fluid that emulsifies fats. Bidder’s canal is a part of the male reproductive system of frogs.

3. Which of these is not a characteristic feature of Rana tigrina?
a) Webbed feet
b) Bilobed tongue
c) Thick, leathery skin
d) Membranous tympanum
Answer: c
Clarification: Rana tigrina or frog possesses a bilobed tongue to capture food. It has webbed feet for the purpose of swimming in water. It also has a membranous tympanum to receive sound signals. It has moist, slippery skin.

4. In frogs, chyme is passed to the ______
a) duodenum
b) ileum
c) jejunum
d) cloaca
Answer: a
Clarification: Duodenum is the first part of the small intestine. Food ingested by the frog is churned with bile, pancreatic juices and hydrochloric acid in the stomach to form an acidic mixture called chyme. This is passed to the duodenum.

5. Pancreatic juice is delivered to the duodenum by the _______
a) pancreatic duct
b) common bile duct
c) parotid duct
d) hepatic duct
Answer: b
Clarification: Pancreatic juice is first delivered from the pancreas to the common bile duct via the pancreatic duct. The common bile duct, which also receives bile from the gall bladder delivers its contents into the duodenum.

6. Where does final digestion take place in frogs?
a) Rectum
b) Cloaca
c) Intestine
d) Bidder’s canal
Answer: c
Clarification: Final digestion in frogs takes place in the intestine where pancreatic juices break down proteins and carbohydrates and bile break down fat. The undigested food moves to the rectum end exits through the cloaca.

7. In frogs, the undigested food passes out through the ______
a) cloaca
b) rectum
c) anus
d) intestine
Answer: a
Clarification: The undigested food in frogs is passed out through the cloaca. The rectum lies before the cloaca. The undigested food is digested completely in the intestine and passed into the cloaca via the rectum.

8. What type of respiration is shown by frogs in water?
a) pulmonary respiration
b) Branchial respiration
c) Subcutaneous respiration
d) Cutaneous respiration
Answer: d
Clarification: Frogs can breathe both on land and in freshwater. In water, the exchange of gases occurs through the moist skin. This type of respiration shown by frogs is known as cutaneous respiration.

9. Cutaneous respiration in frogs takes place by _______
a) endosmosis
b) active transport
c) diffusion
d) exosmosis
Answer: c
Clarification: Frogs can breathe both on land and in water. Frogs breathe in water through the skin. This is known as cutaneous respiration. Cutaneous respiration in frogs takes place by the process of diffusion.

10. Frogs have a lymphatic system. True or false?
a) True
b) False
Answer: a
Clarification: Frogs possess a lymphatic system. The lymphatic system contains lymph, lymph channels and lymph nodes. The circulatory or vascular system of frogs is also well-developed and of closed type.

11. During aestivation in frogs, gaseous exchange takes place through ______
a) Anaerobic respiration
b) Stored oxygen
c) Lungs
d) Skin
Answer: d
Clarification: Frogs show both aestivation and hibernation, which are long periods of rest during the peak summer and peak winter periods, respectively. During aestivation, gaseous exchange takes place through the skin.

12. How many chambers are present in a frog’s heart?
a) 2
b) 4
c) 3
d) 5
Answer: c
Clarification: The heart of a frog has three chambers- two auricles and one ventricle. The heart is covered by a membrane called pericardium. The heart is a muscular structure and is situated in the upper part of the body.

13. What is the shape of the sinus venosus?
a) Spherical
b) Irregular
c) Triangular
d) Cylindrical
Answer: c
Clarification: The sinus venosus is a triangular structure. It receives blood from the vena cava which are major veins of the body. The sinus venosus then joins the right atrium and delivers the deoxygenated blood.

14. In frog, the ventricle opens into ______
a) conus arteriosus
b) sinus venosus
c) hepatic portal vein
d) vena cava
Answer: a
Clarification: The heart of the frog has three chambers- two auricles and one ventricle. The heart is covered by a covering called pericardium. Oxygenated blood leaves the heart through the conus arteriosus.

15. Which of these is not present in frog?
a) Renal portal system
b) Enucleated erythrocytes
c) Hepatic portal system
d) Lymphatic system
Answer: b
Clarification: Frogs have specialized vein connections between the intestine and liver and as well as between the kidneys and the lower parts of the frog body, known as hepatic and renal portal systems. They have a lymphatic system and nucleated erythrocytes.

To practice Zoology Online Quiz,

Biology Multiple Choice Questions on “Biomolecules – Chemical Analysis – 2”.

1. Which amino acid has a methyl group as R?
a) Serine
b) Glycine
c) Valine
d) Alanine
Answer: d
Clarification: Amino acids have a chiral carbon bound with an amino group, an acid group, a hydrogen and an R group. In alanine, the R group is a methyl group. In glycine, the R group is a hydrogen atom.

2. Which amino acid has a hydroxy methyl group as R?
a) Tryptophan
b) Lysine
c) Serine
d) Leucine
Answer: c
Clarification: An amino acid having a chiral carbon, surrounded by an amino group, an acid group, a hydrogen atom and a hydroxymethyl group as the R group is serine. It is a polar amino acid due to its R group.

3. Which of these is an amino acid with pH less than 7?
a) Valine
b) Lysine
c) Glutamic acid
d) Histidine
Answer: c
Clarification: a pH lesser than 7 signifies that the amino acid is acidic in nature. Glutamic acid has pH less than 7, hence it is an acidic amino acid. Histidine and lysine are basic while valine is a neutral amino acid.

4. Which of these is a neutral amino acid?
a) Valine
b) Histidine
c) Lysine
d) Aspartic acid
Answer: a
Clarification: Valine is a neutral amino acid. Histidine and lysine are basic amino acids, having a pH greater than 7, while aspartic acid is an acidic amino acid and has a pH lesser than 7. Valine is hydrophobic.

5. Which of these amino acids is not aromatic?
a) Tyrosine
b) Methionine
c) Tryptophan
d) Phenylalanine
Answer: b
Clarification: Aromatic amino acids are amino acids in which the side-chain contains an aromatic ring. Tyrosine, tryptophan and phenylalanine have aromatic rings in their side chains and are hence, aromatic. Methionine is not aromatic.

6. Which of these statements is not true regarding amino acids?
a) The amino group is ionizable
b) The acidic group is ionizable
c) Structure remains same at different pH
d) Glycine is the simplest amino acid
Answer: c
Clarification: The amino group and the acidic group or an amino acid are both ionizable and can exist in zwitter ionic form. However, due to their ionizable property, their structure does not always remain the same at different pH.

7. How many carbon atoms does palmitic acid contain?
a) 16
b) 14
c) 18
d) 12
Answer: a
Clarification: Palmitic acid is a saturated fatty acid having 16 carbon atoms including the carbon of the carboxyl group. It is water insoluble. It does not have any double bonds in its structure and is hence saturated.

8. How many carbon atoms does arachidonic acid contain?
a) 16
b) 12
c) 18
d) 20
Answer: d
Clarification: Arachidonic acid is a polyunsaturated fatty acid containing 20 carbon atoms. This means that its fatty acid chain contains double bonds. Arachidonic acid contains four cis-double bonds.

9. Glycerol is also known as ______
a) dihydroxy butane
b) methyl butanol
c) trihydroxy propane
d) 3 propanol
Answer: c
Clarification: The formula for glycerol is C₃H₈O₃. It has 3 carbon (C) atoms, 8 hydrogen (H) atoms, and 3 oxygen (O) atoms. each carbon atom is bonded to an -OH (hydroxyl) group. Glycerol has antimicrobial and antiviral properties.

10. Fats have higher melting points than oils. True or false?
a) True
b) False
Answer: a
Clarification: Oils are liquid at room temperature while fats are solid at high temperature. Oils have a lower melting point. The lower melting point of oils is due to the higher degree of unsaturation that is possesses.

11. Which of these makes up the cell membrane?
a) Peptidoglycans
b) Polysaccharides
c) Glycoproteins
d) Phospholipids
Answer: d
Clarification: The cell membrane is a phospholipid bilayer. The polar phosphorus groups are hydrophilic and face outwards while the fatty acid tails are non-polar, hydrophobic and face each other.

12. Which nitrogenous base is not found in RNA?
a) Guanine
b) Adenine
c) Thymine
d) Cytosine
Answer: c
Clarification: Deoxyribonucleic acid (DNA) contains the nitrogenous bases adenine, guanine, cytosine and thymine. However, ribonucleic acid (RNA) contains the nitrogenous bases adenine, guanine, cytosine and uracil instead of thymine.

13. A nucleoside consists of _____
a) sugar, phosphate
b) base, phosphate
c) base, sugar
d) base, sugar, phosphate
Answer: c
Clarification: N nucleoside consists of a nitrogenous base such as adenine, guanine, cytosine or thymine linked to a deoxyribose sugar. When a phosphate group is attached, it is known as a nucleotide.

14. Identify the amino acid.

a) Serine
b) Alanine
c) Valine
d) Glycine
Answer: a
Clarification: The given amino acid has a hydroxy methyl group attached to the alpha carbon or chiral carbon. Hence, the amino acid is serine. Glycine is the simplest amino acid with its R group being an H atom.

15. Identify the nitrogenous base.

a) Thymine
b) Uracil
c) Adenine
d) Guanine
Answer: b
Clarification: The given structure is an aromatic heterocyclic organic compound known as a pyrimidine. It has two nitrogen atoms and four carbon atoms. The given pyrimidine is uracil which is found in RNA.

Biology Multiple Choice Questions on “Cell Cycle”.

1. Which of these processes is not a part of the cell cycle?
a) Duplication of genome
b) Division into daughter cells
c) Synthesis of cell organelles
d) Degeneration of centrosome
Answer: d
Clarification: Cell cycle involves duplication of the genome, division of the parent cell into two daughter cells, synthesis of cell organelles for the daughter cells, but centrosomes are not degenerated.

2. Which of these is the correct order of events in the cell cycle?
a) G1 → G2 → S → M
b) G1 → G2 → M → S
c) G1 → S → G2 → M
d) S → M → G1 → G2
Answer: c
Clarification: The cell cycle starts with the first gap phase or G1, followed by the synthesis phase or S phase. This is followed by the second gap phase or G2. These are parts of the interphase, which is then followed by the M phase.

3. What is the duration of cell cycle in yeast?
a) 30 minutes
b) 24 hours
c) 90 minutes
d) 48 hours
Answer: c
Clarification: The duration of the cell cycle of the single celled fungi yeast takes 90 minutes. This means that it undergoes interphase and M phase to produce two new identical daughter cells through cell division.

4. The period between two M phases is called ______
a) interphase
b) prophase
c) prometaphase
d) telophase
Answer: a
Clarification: Two successive M phases or mitosis phases are separated by a period of rest known as interphase. It is the phase in which newly formed daughter cells actively grow and synthesize cellular material for the next M phase.

5. How much time of the entire cell cycle is occupied by interphase?
a) 75%
b) 95%
c) 50%
d) 80%
Answer: b
Clarification: The cell cycle is broadly classified into two phases-the interphase and the M phase. The M phase is the one in which actual cell division takes place. It occurs rapidly and takes up 95% of the duration of the cell cycle.

6. Identify the phase of the cell cycle.

a) Prophase
b) G0
c) G2
d) Telophase
Answer: c
Clarification: The phase to be identified lies between the S phase or the synthesis phase and the M phase or the mitosis phase. Hence, it is the G2 phase or the gap phase 2. Cell growth takes place during this phase.

7. Which process does the M phase of cell cycle start with?
a) Karyokinesis
b) Cytokinesis
c) Interphase
d) Spindle formation
Answer: a
Clarification: The M phase of the cell cycle starts with karyokinesis or the separation of sister chromatids. It ends with cytokinesis or the division of the cytoplasm. The M phase occurs after interphase.

8. In which phase of the cell cycle does DNA replication take place?
a) Anaphase
b) Metaphase
c) Prophase
d) Interphase
Answer: d
Clarification: DNA replication or synthesis takes place in the resting phase or interphase of the cell cycle. It takes place during the S phase or synthesis phase. Prophase, metaphase and anaphase are a part of M phase.

9. What is the interval between mitosis and DNA replication?
a) S phase
b) G2 phase
c) G1 phase
d) M phase
Answer: c
Clarification: G1 phase or gap 1 phase is the interval between the end of mitosis or M phase and the beginning of the replication or the synthesis of DNA in the synthesis phase. G2 phase follows the S phase.

10. DNA synthesis involves an increase in chromosome number. True or false?
a) True
b) False
Answer: b
Clarification: DNA synthesis does not increase the chromosome number. Only the amount of DNA in the cell increases. It doubles in quantity in order to divide it equally between two daughter cells to be produced as a result of mitosis.

11. During S phase of the cell cycle, the amount of DNA ______
a) triples
b) remains the same
c) quadruples
d) doubles
Answer: d
Clarification: During S phase or synthesis phase, DNA synthesis or replication takes place. This is because at the end of every cell division, the cell splits into two daughter cells which have equal amount of DNA. Hence the amount of DNA doubles.

12. In which phase of the cell cycle does centriole duplication take place?
a) S phase
b) G2 phase
c) G1 phase
d) G0 phase
Answer: a
Clarification: Centriole duplication as well as DNA duplication or synthesis takes place in the S phase or the synthesis phase of the cell cycle. DNA duplication does not take place in the gap phases G1, G2 and G0.

13. Protein synthesis takes place in _____
a) G0 phase
b) G1 phase
c) G2 phase
d) S phase
Answer: c
Clarification: Proteins are synthesized in the interphase in order to help initiate the M phase or mitosis phase and so that the two daughter cells each receive adequate protein. It takes place in G2 phase.

14. Which of these cells do not divide?
a) Heart cells
b) Melanocytes
c) Osteocytes
d) Liver cells
Answer: a
Clarification: Melanocytes, osteocytes and liver cells show cell division. Heart cells do not show cell division as the cells have exited the G1 or first gap phase in order to enter a quiescent stage or the G0 phase.

15. In which of these animals does a haploid cell divide mitotically?
a) Humans
b) Male honey bees
c) Female honey bees
d) Rats
Answer: b
Clarification: Haploid cells which have only one copy of chromosomes divide mitotically in male honey bees. This is in contrast to the general pattern of haploid germ cells dividing meiotically in most animals.