Category: Class 11 Biology Objective Questions

Biology Question Bank for Class 11 on “Biological Classification – Fungi – 2”.

1. Phycomycetes are also called as ______
a) Sac fungi
b) Conjugation fungi
c) Club fungi
d) Imperfect fungi
Answer: b
Clarification: Phycomycetes are also called as Conjugation fungi. Because, phycomycetes can reproduce using dissimilar gametes i.e. anisogamous fertilization can take place and hence came the name conjugation fungi.

2. Rhizopus belongs to _________
a) Phycomycetes
b) Ascomycetes
c) Basidiomycetes
d) Deuteromycetes
Answer: a
Clarification: Rhizopus also called as bread mold belongs to Phycomycetes or conjugation fungi. Other well known examples of Phycomycetes or Conjugation fungi are Mucor and Albugo (Mustard fungi).

3. Which among the following are incorrect about Phycomycetes?
a) Phycomycetes are aseptate fungi and are coenocytic
b) Phycomycetes are also called as algal fungi
c) Zygospores are formed due to isogamous fertilization and zoospores are formed due to anisogamous fertilization
d) Phycomycetes are also called as conjugation fungi
Answer: c
Clarification: Zygospores are formed either due to isogamous or anisogamous fertilization. Zoospores and aplanospores are motile and non-motile spores produced due to asexual mode respectively. Phycomycetes are aseptate fungi and are coenocytic. Phycomycetes are also called as algal fungi or conjugation fungi.

4. Non-motile spores in Phycomycetes are called as _____
a) Phycospores
b) Zoospores
c) Aplanospores
d) Zygospores
Answer: c
Clarification: Non-motile spores in Phycomycetes are called as Aplanospores and motile spores are known as Zoospores. Fusion of similar or dissimilar gametes through sexual mode results in Zygospores.

5. Asexual spores in Ascomycetes are called as _______
a) Ascospores
b) Conidia
c) Sporangiospores
d) Aeciospores
Answer: b
Clarification: Asexual spores in Ascomycetes are called Conidia and are produced exogenously by conidiocarps. Sexual spores in Ascomycetes are called Ascospores and are produced endogenously in asci present inside Ascocarps.

6. Which among the following is incorrect about Ascomycetes?
a) Mycelium in Ascomycetes is septate and coenocytic
b) Ascomycetes are also called Sac fungi
c) Asexual spores in Ascomycetes are called as Conidia and are produced exogenously by conidiocarps
d) Sexual spores in Ascomycetes are called as Ascospores and are produced endogenously by Ascocarps
Answer: a
Clarification: Mycelium in Ascomycetes are septate and branched but not coenocytic. Ascomycetes are also called Sac fungi. Asexual spores in Ascomycetes are called as Conidia and are produced exogenously by conidiocarps. Sexual spores in Ascomycetes are called as Ascospores and are produced endogenously by Ascocarps.

7. Pencillium belongs to _________
a) Ascomycetes
b) Phycomycetes
c) Basidiomycetes
d) Deuteromycetes
Answer: a
Clarification: Pencillium belongs to Ascomycetes. Other well-known examples of Ascomycetes comprise of yeast, aspergillus and Neurospora. Pencillium is also used in preparation of drugs like Penicillin.

8. The figure shown below belongs to _______

a) Ascomycetes
b) Basidiomycetes
c) Phycomycetes
d) Deuteromycetes
Answer: b
Clarification: The figure given above shows Mushroom. Mushroom (Agaricus) is an example of Basidiomycetes. Other well known examples of Basidiomycetes include Puccina (Rust fungi), Puff balls and Bracket fungi.

9. Puccina is also called as _____
a) Mustard fungi
b) Rust fungi
c) Bracket fungi
d) Bread mold
Answer: b
Clarification: Puccina is also called as Rust fungi and is an example of Basidiomycetes. Albugo is also known as Mustard fungi and is an example of Phycomycetes. Rhizopus which is an example of Phycomycetes is also called as Bread mold.

10. Which among the following is incorrect about Basidiomycetes?
a) Basidiomycetes is also called as Club fungi
b) Basidiomycetes grow on soil, tree logs and plants
c) Mucor, Puccina and Puff balls are examples of Basidiomycetes
d) Basidiospores are sexual spores in Basidiomycetes
Answer: c
Clarification: Muccor is an example of Phycomycetes. Basidiomycetes are also called as Club fungi. Basidiomycetes grow on soil, tree logs and plants. Basidiospores are sexual spores in Basidiomycetes.

11. Basidiomycetes reproduce asexually through Conidia.
a) True
b) False
Answer: b
Clarification: Basidiomycetes don’t have asexual spores. Sexual spores in Basidiomycetes are called as Basidiospores and are produced exogenously on Basidium in fruiting bodies called Basidiocarps.

12. Scientific name of common mushroom is ______
a) Albugo
b) Agaricus bisporus
c) Stolonifer
d) Muccidae
Answer: b
Clarification: Agaricus bisporus is the binomial nomenclature of the mushroom. Mushroom belongs to the division of Basidiomycetes and class of Agaricomycetes. It belongs to the family Agaricaceae and order Agaricales.

13. Which among the following can’t produce spores sexually?
a) Ascomycetes
b) Basidiomycetes
c) Phycomycetes
d) Deuteromycetes
Answer: d
Clarification: Deuteromycetes can’t produce spores sexually. Asexual spores in Deuteromycetes are called as Conidia. Deuteromycetes are also called as imperfect fungi due to absence of sexual reproduction.

14. Which among the following statements are incorrect?
a) Asexual spores are formed due to mitosis
b) Bracket fungi are an example of ascomycetes
c) Basidiomycetes produce sexual spores called Basidiospores exogenously in Basidium
d) Deuteromycetes reproduce asexually by Conidia
Answer: b
Clarification: Bracket fungi are an example of Basidiomycetes. Asexual spores are formed due to mitosis. Basidiomycetes produce sexual spores called basidiospores exogenously in Basidium. Sexual spores are absent in Deuteromycetes but reproduce asexually through Conidia.

15. All Ascomycetes are multi-cellular eukaryotic fungi.
a) True
b) False
Answer: b
Clarification: Yeast belongs to the division of Ascomycetes. Yeast is a unicellular eukaryotic fungus. All Ascomycetes are multi-cellular eukaryotic fungi except Yeast. Other familiar examples of Ascomycetes include Yeast, Aspergillus, Pencillium and Neurospora etc.

To practice Biology Question Bank for Class 11,

Biology Multiple Choice Questions on “Classification of Animal Kingdom into Different Phylum-1”.

1. Opening on the upper side of spongocoel _________
a) Osculum
b) Cnidoblasts
c) Spicules
d) Ostia
Answer: a
Clarification: Minute pores called Ostia let water into a central cavity called spongocoel. An opening on the upper side of the spongocoel that helps in egestion of water is called as Osculum.

2. Which among the following is incorrect about transport canal system in Porifera?
a) Water enters the cavity through minute pores called as ostia
b) Flagellated cells create water currents inside spongocoel
c) Collar cells help in the distribution and filtering of food materials
d) Water leaves the spongocoel through Osculum
Answer: c
Clarification: Water enters the central cavity through minute pores called as ostia and leaves the cavity through Osculum. Flagellated cells create water currents inside spongocoel. Collar cells filter the food materials and amoeboid cells distribute food materials.

3. Choanocytes are also called as ________
a) Flagellated cells
b) Collar cells
c) Amoeboid cells
d) Epidermal cells
Answer: b
Clarification: Choanocytes are also called as collar cells. They filter the food materials present in the water that enters the central cavity through minute spores called Ostia. This water leaves the central cavity through an opening called Osculum.

4. The property of not having separate sexes in an organism is called as __________
a) Hermaphrodite
b) Oogamous
c) Homogamous
d) Heterogamous
Answer: a
Clarification: The property of not having separate sexes in an organism is called Hermaphrodite. In organisms of this kind eggs and sperms are produced by the same individual. Example: Sponges

5. Transport or canal system in Porifera helps in exchange of gases, distribution of food, water removal, gathering of food and formation of new individual.
a) True
b) False
Answer: b
Clarification: Transport or canal system in Porifera helps in exchange of gases, distribution of food, water removal, gathering of food. Canal system can’t help in formation of new individual. Porifera undergoes either fragmentation or sexual reproduction to form a new individual.

6. Which among the following is incorrect about Porifera?
a) The name Porifera comes from the pores present on the surface of the sponges
b) A hard and protective skeleton made up of spongin or spicules supports the body
c) Development of embryo takes place through an intermediate larval stage
d) The digestive system in Porifera is incomplete
Answer: d
Clarification: The name Porifera comes from the pores present on the surface of sponges. A hard and protective skeleton made up of sponging or spicules supports the body. Development of embryo takes place through an intermediate larval stage. The digestive system in Porifera is absent.

7. Some sponges are radially symmetrical
a) True
b) False
Answer: a
Clarification: Most of the sponges are asymmetric whereas few sponges are radially symmetrical. For example, in case of sea stars bilateral symmetry is seen in the initial stage and radial symmetry in adult forms.

8. Which among the following is incorrect about Coelenterata?
a) Tissue level of organization is present in Coelenterata
b) Sea anemone exists in colonies
c) They have two layers of cells in their body i.e. they are diploblastic
d) They have a complete digestive system
Answer: d
Clarification: Tissue level of organization is present in Coelenterata. Sea anemone exists in colonies. Coelenterates have two layers of cells in their body i.e. they are diploblastic. They have an incomplete digestive system.

9. Which among the following is incorrect about Cnidarians?
a) They are also called as coelenterates which means they are fully bellied
b) The name Cnidaria is due to presence of stinging capsules called cnidoblasts on the surface of their tentacles
c) Endodermal cells contain muscle and nerve cells that help in their mobility
d) Hypostome helps in ingestion and egestion
Answer: c
Clarification: Cnidarians are also called coelenterates which mean that they are fully-bellied. The name Cnidaria is due to presence of stinging capsules called cnidoblasts on their surface of their tentacles. Ectodermal cells contain muscle and nerve cells that help in their mobility. Hypostome helps in ingestion and egestion.

10. Coelenterates that are umbrella shaped are called as ______
a) Medusa
b) Polyp
c) Taenia
d) Auerelia
Answer: a
Clarification: Coelenterates that are umbrella shaped are called Medusa and those that are cylindrical are called Polyp. Some cnidarians exhibit metagenesis i.e. both forms exist in alternative generations.

11. Which among the following statements are incorrect about coelenterates?
a) Coelenterates are acoelomates
b) Tentacles have stinging capsules called cnidocytes that help in catching of prey
c) In most of the cases, medusa is sessile
d) Corals have skeleton that is made up of CaCO₃
Answer: c
Clarification: Coelenterates are acoelomates. Tentacles have stinging capsules called cnidocytes that help in catching of prey. In most of the cases, polyp is sessile. Corals have skeleton that is made up of CaCO₃.

12. The property of emitting light from a living organism is called as ________
a) Bioluminescence
b) Phosphorescence
c) Biophosphorescence
d) Cytoluminescence
Answer: a
Clarification: The property of emitting light from a living organism is called bioluminescence. This is a notified property in case of Ctenophores which are also called as Comb jellies or sea walnuts.

13. Which among the following statements is incorrect about ctenophores?
a) Ctenophores are radially symmetrical
b) They are diploblastic
c) They reproduce both sexually and asexually
d) They have ciliated comb plates on their body
Answer: c
Clarification: Ctenophores are radially symmetrical. They are diploblastic. They reproduce only by sexual reproduction. They have eight rows of ciliated comb plates on their body. Examples of Ctenophores are Ctenoplana and Pleurobrachia.

14. Which among the following statements is incorrect about Obelia?
a) Obelia (polyp) produces medusa by fragmentation
b) Medusae undergoes sexual reproduction to produce polyp
c) Obelia exists in both the forms in alternate generations
d) This process is called metagenesis
Answer: a
Clarification: Obelia (polyp) produces medusa by budding. Medusae undergoes sexual reproduction to produce polyp. Obelia exists in both the forms in alternate generations. This process is called metagenesis.

15. Which among the following is called “Portuguese man of war”?
a) Pennatula
b) Physalia
c) Adamsia
d) Meandrina
Answer: c
Clarification: Pennatula, Physalia, Adamsia and Meandrina are also called as Sea-pen, Portuguese man of war, Sea anemone and Brain coral respectively. All the above organisms belong to the phylum Coelenterata.

Botany Exam Questions and Answers on “Anatomy of Dicotyledonous Plant”.

1. Which among the following is incorrect about the anatomy of dicot root?
a) The layer just inside the endodermis in a dicot root is called pericycle
b) The portion between endodermis and epidermis is covered by parenchyma cells
c) Secondary growth initiates from the cells of pericycle
d) Pith in a dicot root quite larger than that of a mono cot root
Answer: d
Clarification: The layer just inside the endodermis in a dicot root is called pericycle. The portion between endodermis and epidermis is covered by parenchyma cells. Secondary growth initiates from the cells of pericycle. Pith in a mono cot root is quite larger than that of a dicot root.

2. Which among the following is an incorrect statement about the anatomy of a dicot root?
a) More xylem bundles are present in a dicot root
b) Conjunctive tissues are made of parenchymatic cells
c) Cortex is made of schlerenchymatous cells
d) Intercellular spaces are absent in endodermis
Answer: c
Clarification: More xylem bundles are present in a dicot root. Conjunctive tissues are made of parenchymatic cells. Intercellular spaces are absent in endodermis. Cortex is made of parenchymatic cells.

3. Conjunctive cells are present only in dicot root and absent in monocot roots.
a) True
b) False
Answer: a
Clarification: Conjunctive cells are present only in dicot root and absent in monocot roots. These are the cells that lie in between xylem and phloem of a dicot root. Such kind of cells are absent in monocot root.

4. Which among the following is incorrect about dicot stem?
a) Xylem and phloem are vascular bundles are arranged in a ring like fashion
b) Hypodermis is present just below the epidermis
c) The vascular bundles are of open type
d) Pith is made of vascular bundles
Answer: d
Clarification: Xylem and phloem are vascular bundles are arranged in a ring like fashion. Hypodermis is present just below the epidermis. The vascular bundles are of open type. Pith is made of parenchyma cells.

5. Cortical layers of a dicot stem are made of collenchyma cells.
a) True
b) False
Answer: b
Clarification: Cortical layers of a dicot stem are made of thin-walled parenchyma cells. Parenchyma cells are therefore called packing cells as they cover almost every region that are left empty.

6. Vascular bundles, pericycle and pith are combinedly called stele.
a) True
b) False
Answer: a
Clarification: Vascular bundles, pericycle, pith and all other tissues inside the endodermis are combinedly called stele. The central portion of any plant cross section is called “Pith”. The portion outside the endodermis constitutes the cortex.

7. Which among the following is incorrect about anatomy of a dicot stem?
a) Epidermis is covered with a thin layer of cuticle and it bears few stomata and trichomes
b) The hypodermis is made of collenchymatous cells and is present just below the epidermis
c) Cortex is made of parenchymatic cells with conspicuous intercellular spaces
d) Endodermis are also called as wax sheath as they are rich in waxy materials
Answer: d
Clarification: Epidermis is covered with a thin layer of cuticle and it bears few stomata and trichomes. The hypodermis is made of collenchymatous cells and is present just below the epidermis. Cortex is made of parenchymatic cells with conspicuous intercellular spaces. Endodermis of a dicot stem is also called as starch sheath as they are rich in waxy materials.

8. Which among the following is incorrect about anatomy of the dicot leaf?
a) Mesophyll is the portion in between adaxial and abaxial epidermis
b) Mesophyll that performs photosynthesis are called palisade parenchyma and spongy parenchyma
c) Spongy parenchyma are placed towards the adaxial epidermis
d) Palisade parenchymatic cells are elongated cells that are arranged parallel to each other
Answer: c
Clarification: Mesophyll is the portion in between adaxial and abaxial epidermis. Mesophyll cells that perform photosynthesis are called palisade parenchyma and spongy parenchyma. Spongy parenchyma cells are placed towards the abaxial epidermis. Palisade parenchymatic cells are elongated cells that are arranged parallel to each other.

9. Vascular bundles are surrounded by _________
a) Bundle sheath cells
b) Endodermis
c) Epidermis
d) Hypodermis
Answer: a
Clarification: Vascular bundles are surrounded by bundle sheath cells. Sometimes these cells contain chloroplasts and helps in carrying photosynthesis. These are tightly packed sheaths around the veins of the leaf.

10. The central portion of the stem is called ________
a) Pith
b) Cortex
c) Vascular bundles
d) Ground tissue
Answer: a
Clarification: The central portion of the stem or a root or a leaf is called the pith. Cortex is the region outside the endodermis. Vascular bundles are those that help in transportation of food and water. Ground tissue is that region of a plant excluding vascular bundles and epidermis.

To practice Botany Exam Questions and Answers,

Zoology Aptitude Test on “Animals Structural Organisations – Cockroach-3”.

1. What is the function of Malpighian tubules in cockroach?
a) Locomotion
b) Circulation
c) Digestion
d) Excretion
Answer: d
Clarification: The Malpighian tubules are used for the purpose of excretion in cockroach. They help to remove the waste material from the hemolymph. Malpighian tubules are yellow in color, thin and filamentous.

2. Which of these is not a division of hindgut in cockroach?
a) Ileum
b) Colon
c) Duodenum
d) Rectum
Answer: c
Clarification: The hindgut of the cockroach is divided into three parts, namely, the ileum, the colon and the rectum. Duodenum is not a structure of the hindgut. The hindgut is broader than the midgut of the cockroach.

3. Which of these characteristics is true about the vascular system of cockroach?
a) Closed type
b) Red hemolymph
c) Poorly developed blood vessels
d) Haemocoel does not contain visceral organs
Answer: c
Clarification: The vascular system in cockroach is of open type. They have poorly developed blood vessels which open up into the haemocoel, where visceral organs are located. The hemolymph is colorless and contains hemocytes and plasma.

4. Which of these structures is involved in blood circulation in cockroach?
a) Ostia
b) Malpighian tubules
c) Ommatidia
d) Phallomere
Answer: a
Clarification: Out of the given structures, ostia is involved in blood circulation. It is present on either side of the funnel-shaped heart chambers. The circulatory system is of open type. Blood from the sinuses is pumped into the heart chambers through ostia.

5. Which of these statements is true about the respiratory system of cockroach?
a) Exchange of gases takes place through active transport
b) Sphincters are present at the openings of spiracles
c) There are 8 pairs of spiracles
d) Spiracles are absent on the lateral sides of the body
Answer: b
Clarification: Sphincters are present at the openings of spiracles and regulate its opening and closing. Exchange of gases takes place through diffusion at the tracheoles. There are 10 pairs of spiracles which are located on the lateral side of the body.

6. Cockroaches are _________
a) ammonotelic
b) ureotelic
c) uricotelic
d) annelids
Answer: c
Clarification: Cockroaches excrete waste in the form of uric acid. Hence, they are uricotelic organisms. The waste is excreted from the hindgut. Cockroaches belong to the class Insecta of the phylum Arthropoda.

7. Which of these structures do not help in excretion in cockroaches?
a) Ostia
b) Fat body
c) Nephrocytes
d) Uricose gland
Answer: a
Clarification: Fat body, nephrocytes and uricose gland help in excretion in cockroach. Cockroaches are uricotelic, which means they excrete their waste in the form of uric acid. Ostia is a part of the circulatory system.

8. How many ganglia lie in the thorax and abdomen respectively in cockroach?
a) 3, 6
b) 6, 3
c) 2, 4
d) 4, 2
Answer: a
Clarification: The nervous system of cockroach consists of a series of fused ganglia which are segmentally arranged. There are three ganglia present in the thorax and six ganglia present in the abdomen.

9. For how long will a cockroach survive if its head is cut off?
a) One day
b) Two weeks
c) One week
d) Two days
Answer: c
Clarification: A cockroach will survive for as long as one week if its head is cut off. This is because the nervous system of the cockroach is spread out all over its body. Parts of the nervous system lie on the ventral side of the body apart from its head.

10. The compound eyes of cockroach are situated dorsally. True or False?
a) True
b) False
Answer: a
Clarification: The compound eyes of cockroach are present on the dorsal side of its head. Each eye of the cockroach consists of around 2000 ommatidia through which the cockroach receives several images of an object.

11. Which of these is not a sense organ in cockroach?
a) Maxillary palps
b) Labial palps
c) Anal cerci
d) Ostia
Answer: d
Clarification: The maxillary palps, labial palps and anal cerci are some of the sense organs in cockroach. Ostia are not sensory organs but a part of the circulatory system. They are located on either side of the heart chambers.

12. Cockroaches are ________
a) hermaphrodite
b) monoecious
c) dioecious
d) bisexual
Answer: c
Clarification: Cockroaches are dioecious. This means that the male and female reproductive organs of cockroach are present separately. Hence, they are not bisexual, hermaphrodite and monoecious as these have both the organs in the same animal.

13. Which of these is an external organ in male cockroach?
a) Gonopore
b) Ejaculatory duct
c) Phallomere
d) Seminal vesicle
Answer: c
Clarification: The phallomere or male gonapophysis is an external organ in male cockroach. The male gonopore, the ejaculatory duct and the seminal vesicle are internal structures. All the structures are a part of the male reproductive system.

14. How many ovarioles are present in a female cockroach?
a) 16
b) 8
c) 10
d) 6
Answer: a
Clarification: The female cockroach possesses two large ovaries. Each ovary contains 8 ovarioles or ovarian tubules. Thus, the total number of ovarioles present in the female cockroach is double of 8, that is, 16.

15. Cockroaches are ________
a) ametabolous
b) paurometabolous
c) hemimetabolous
d) holometabolous
Answer: b
Clarification: Cockroaches are paurometabolous. This means that they undergo metamorphosis and develop through the nymph stage. The nymphs undergo moulting or shedding of skin around 13 times to attain adult form.

To practice Zoology Aptitude Test,

Biology Quiz for Medical Entrance Exams on “Biomolecules-3”.

1. Enzymes are biocatalysts i.e. they increase the rate of reaction of metabolic reactions.
a) True
b) False
Answer: a
Clarification: Enzymes are biocatalysts i.e. they increase the rate of reaction of metabolic reactions. The reactant that takes part in metabolic reaction is called substrate. Rate of reaction = (dx/dt). Here, x = concentration of substrate and t refers to the time.

2. Which among the following is incorrect about enzymes?
a) Pepsin helps in breaking of proteins
b) Lipase breaks lipids
c) Amylase breaks vitamins
d) Enzymes have a three dimensional structure and this structure has active sites
Answer: c
Clarification: Pepsin helps in breaking of proteins. Lipase breaks lipids. Amylase breaks starch into sugars. Enzymes have a three dimensional structure and this structure has active sites in them.

3. Which among the following is incorrect about amino acids?
a) Enzymes are named after compounds/ class on which they act and their names end with “-ase”
b) Oxidoreductase reduces few substrates whereas oxidizes few other substrates
c) Enzyme kinetics is governed by Michael-Menden equation
d) Enzymes take part in the reaction and increase the rate of reaction
Answer: d
Clarification: Enzymes are named after compounds/ class on which they act and their names end with “-ase”. Oxidoreductase reduces few substrates whereas oxidizes few other substrates. Enzyme kinetics is governed by Michael-Menden equation. Enzymes don’t take part in the reaction but increase the rate of reaction.

4. Which among the following does not affect the activity of the enzyme after a particular point?
a) Temperature
b) PH
c) Concentration of substrates
d) Competitive inhibitor
Answer: d
Clarification: Temperature, pH, competitive inhibitor, concentration of substrates and enzymes are the factors that affect the activity of enzyme. Rate of reaction increases with the concentration of enzyme and substrate but remains unaffected after a particular rate.

5. Transferase catalyzes oxidation and reduction between 2 substrates.
a) True
b) False
Answer: b
Clarification: Oxidoreductase catalyses oxidation and reduction between 2 substrates. Transferase is an enzyme catalyses the transfer of specific functional groups from one molecule to another.

6. Enzymes that link covalent bond between substrates to form a large molecule are called _______
a) Isomerases
b) Lyases
c) Ligases
d) Transferases
Answer: a
Clarification: Enzymes that link covalent bond between substrates to form a large molecule are called ligases. Lyases are enzymes that break covalent bonds of large molecules. Isomerases are the enzymes that isomerize a specified compound.

7. Which among the following nucleotide is not present in DNA?
a) Adenine
b) Thymine
c) Cytosine
d) Uracil
Answer: d
Clarification: The four nucleotides that are present in DNA are Adenine, Thymine, Cytosine and Guanine. Uracil is absent in DNA but not present in RNA. Adenine binds with Thymine and Guanine binds with Cytosine in DNA.

8. Which among the following is incorrect about RNA?
a) RNA is always less stable than DNA because of the two –OH on 1’ and 2’ carbons of oxy ribose
b) RNA has uracil whereas DNA has thymine
c) RNA is single stranded whereas DNA is double-stranded
d) RNA on hydrolysis gives ribose sugar
Answer: a
Clarification: RNA is always less stable than DNA because of the two –OH on 2’ and 3’ carbons of oxy ribose. RNA has uracil whereas DNA has thymine. RNA is single stranded whereas DNA is double-stranded. RNA on hydrolysis gives ribose sugar.

9. Which among the following is incorrect about RNA?
a) RNA is of 3 types i.e. r-RNA, m-RNA and t-RNA
b) m-RNA carries the code for protein synthesis in terms of three nucleotide bases called codons
c) Each codon will represent a unique amino acid and an amino acid is represented by a unique codon
d) r-RNA synthesis the proteins and t-RNA will recognize the codons
Answer: c
Clarification: RNA is of 3 types i.e. r-RNA, m-RNA and t-RNA. m-RNA carries the code for protein synthesis in terms of three nucleotide bases called codons. Each codon will represent a unique amino acid and amino acids can be represented redundantly. r-RNA synthesis the proteins and t-RNA will recognize the codons.

10. Which among the following is incorrect about lipids?
a) These are heterogeneous organic compounds comprising of C, H and O
b) These are water insoluble and release more energy as compared to carbohydrates
c) These also act as water barrier and messenger and are constituents of plant
d) Phospholipids are an example of simple fatty acids
Answer: d
Clarification: Lipids are heterogeneous organic compounds comprising of C, H and O. These are water insoluble and release more energy as compared to carbohydrates. These also act as water barrier and messenger and are constituents of plant. Phospholipids are an example of compound fatty acids.

To practice Biology Quiz for Medical Entrance Exams,

Biology Multiple Choice Questions on “Biomolecules – Enzymes and Biocatalysts-1”.

1. Which of these enzymes are not proteinaceous?
a) Kinases
b) Endonucleases
c) Ligases
d) Ribozymes
Answer: d
Clarification: Kinases, endonucleases and ligases are proteins in nature. They are made out of repeating units of amino acids. However, ribozymes are not proteins but are nucleic acids that act as enzymes.

2. At which part of the enzyme does the substrate fit in?
a) Left end
b) Right end
c) Active site
d) Binding site
Answer: c
Clarification: In order to catalyze a reaction, the substrate must bind to enzyme at its active site. Following this, an enzyme-substrate complex is formed which ultimately leads to the formation of the product.

3. How are enzymes different from catalysts?
a) Enzymes are active at high temperatures
b) Catalysts are active at subzero temperatures
c) Catalysts are efficient at high temperatures and high pressures
d) Enzymes are denatured at room temperature
Answer: c
Clarification: Enzymes are organic catalysts or biocatalysts. However, inorganic catalysts work at high temperatures and high pressures efficiently. Enzymes, being proteinaceous in nature, get denatured under such conditions.

4. Up to what temperature does the enzymes of thermophilic organisms stay active?
a) 90°C
b) 40°C
c) 35°C
d) 200°C
Answer: a
Clarification: Thermophilic organisms can survive at very high temperatures. Therefore, the enzymes produced by them are thermally stable. The enzymes produced by them are active up to temperatures such as 90°C.

5. Which of these statements is true about physical changes?
a) It involves the breaking of bonds
b) It involves a change in shape
c) It does not involve a change in shape
d) Melting of ice is a physical change
Answer: b
Clarification: Physical changes involve a change in the shape of a substance but it does not involve the breaking of bonds. Physical changes are reversible, unlike chemical changes. The melting of ice is a physical change.

6. Which of these is an example of a chemical change?
a) Melting of ice
b) Evaporation of water
c) Hydrolysis of glucose
d) Rusting of iron
Answer: c
Clarification: The melting of ice into water, the evaporation of water to water vapor and the freezing of water are examples of physical changes. However, the hydrolysis of glucose involves the breaking of bonds. It is a chemical change.

7. How can we express the rate of a physical or chemical process?
a) Amount of product formed per unit time
b) Amount of precipitate formed per unit time
c) Amount of substrate used per unit product
d) Amount of time taken per unit product
Answer: a
Clarification: The rate of a physical change or a chemical change can be expressed by the amount of product formed per unit time. Physical changes are reversible but chemical changes are not reversible.

8. What happens to the rate of a chemical reaction when that is a 10°C change in either direction?
a) The rate does not change
b) The rate becomes half
c) The rate doubles
d) The rate doubles or becomes half
Answer: d
Clarification: The temperature of a reaction is one of the factors that affect the rate of a reaction. When there is a 10°C change in either direction then the rate of the reaction doubles or becomes half of its original value.

9. What reaction is catalyzed by carbonic anhydrase?
a) Breakdown of lipids
b) Formation of cholesterol
c) Formation of carbonic acid
d) Breakdown of carbohydrates
Answer: c
Clarification: Carbonic anhydrase is an enzyme that catalyzes the formation as well as the breakdown of carbonic acid. Carbonic anhydrase is proteinaceous in nature and it can be denatured at high temperatures.

10. When the direction is specified, then the rate of a reaction is also called its velocity. True or false?
a) True
b) False
Answer: a
Clarification: The rate of a reaction is defined as the amount of product formed per unit time. When the direction of the reaction is specified, then the rate of the reaction is also known as the velocity of the reaction.

11. If the formation of carbonic acid is uncatalyzed, how many product molecules are formed every hour?
a) 25
b) 50
c) 100
d) 200
Answer: d
Clarification: The formation of carbonic acid can be catalyzed by the enzyme carbonic anhydrase. When this reaction is uncatalyzed, 200 molecules of carbonic acid are formed every hour. The presence of a catalyst increases the rate by about 10 million times.

12. How many molecules of pyruvic acid are formed from 8 molecules of glucose?
a) 8
b) 24
c) 16
d) 32
Answer: c
Clarification: Glucose is converted to pyruvic acid via a metabolic pathway known as glycolysis. 1 molecule of glucose yields 2 molecules of pyruvic acid. Thus, 8 molecules of glucose yield 16 molecules of pyruvic acid.

13. How many carbon atoms do five molecules of pyruvic acid contain?
a) 25
b) 5
c) 15
d) 20
Answer: c
Clarification: Pyruvic acid contains three atoms of carbon. Therefore, five molecules of pyruvic acid contain 15 atoms of carbon. Pyruvic acid is the end product of glycolysis, which is a ten-step metabolic pathway.

14. What is the end product of glycolysis under anaerobic conditions?
a) Lactic acid
b) Pyruvic acid
c) Oxalic acid
d) Ascorbic acid
Answer: a
Clarification: Glycolysis is a ten-step metabolic pathway that converts one molecule of glucose into two molecules of pyruvic acid. Under anaerobic conditions, glucose is converted into two molecules of lactic acid.

15. Yeast ferments glucose into _____
a) aldehyde
b) ethanol
c) ketone
d) lactic acid
Answer: b
Clarification: Yeast is the simplest unicellular eukaryotic organism and belongs to the kingdom Fungi. It anaerobically digests or ferments glucose to produce ethanol or ethyl alcohol, along with carbon dioxide.