assertion reason Biology test

assertion reason Biology test
objective type multiple choice assertion-reason type questions from Biology
Biology Assertion & Reason for Competitive Examinations
Directions: The following items consist of two statements are labelled the ‘Assertion A’ and the other labelled the ‘Reason R’. You are to examine these two statements carefully and decide if the Assertion A and the Reason. R are individually true and if so, whether the Reason is a correct explanation of the Assertion. Select your answer to these items using the codes given below and mark your answer sheet accordingly.
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true but l. is not a correct explanation of A
(c) A is true but R is false
(d) A is false but R is true
1. Assertion (A): The degeneration of tadpole tail occurs during metamorphosis.
Reason (R): This degeneration is brought about by hydrolytic enzymes.
Ans. (a)

2. Assertion (A): Geological evidence indicates that free oxygen began accumulating in the atmosphere about two billion year ago.
Reason (R): The free oxygen in the atmosphere is produced by cyanobacteria like forms.
Ans. (d)

3. Assertion (A): Thalassaemia is a dreaded disease of blood caused by structural variations in or globin chains.
Reason (R): Structural variations in globin chains are due to amino acid replacements.
Ans. (a)

4. Assertion (A): Prokaryote cells prolife-rate at a much more rapid rate than eukaryotes.
Reason (R): In prokaryotes there is no condensation of the chromosomes, no spindle apparatus and they follow a simple duplication and separation of DNA pattern.
Ans. (a)

5. Assertion (A): Each gene can exist in a variety of different forms called alleles.
Reason (R): Different alleles of the same gene arise by heritable changes (mutations) in the gene itself.
Ans. (a)

6. Assertion (A): Pila produces two types of sperm, namely eupyrene and oligopyrene.
Reason (R): Eupyrene sperm has XX chromosomes and can produce only female while oligopyrene sperm has XV chromosomes and can produce only male.
Ans. (c)

7. Assertion (A): Echinodermata and Hemichordata are both deuterostomes.
Reason (R): During early development of these ‘phyla, the blastopore becomes the mouth opening.
Ans. (c)

8. Assertion (A): Bryozoa is now divided into two separate phylaendoprocta and Ectoprocta
Reason (R): Though Endoprocta has some superficial similarities with Ectoprocta, the former is acoelomate and the latter acoelomate.
Ans. (c)

9. Assertion (A): The ‘killer’ stains of Paramecium aurelia produce a toxic substance (paramecin) which kills the ‘sensitive’ ones.
Reason (R): Such ‘killer’ stains lack the Kappa particles.
Ans. (c)

10. Assertion (A): The adults of echinoderms generally exhibit pentamerous radial symmetry.
Reason (R): A unique ambulacral system is typically present in echinoderms.
Ans. (b)

11. Assertion (A): Balanoglossus is not a chordate.
Reason (R): The so-called notochord of Balanoglossus is only pre-oral extension of the gut.
Ans. (a)

12. Assertion (A): In birds, the synsacrum is fused with the pelvic girdle.
Reason (R): The synsacrum provides a rigid framework for perching.
Ans. (c)

13. Assertion (A): The accidental leak of methyl isocyanate from a storage tank of a factory in Bhopal in 1980 killed more than 25, 000 people.
Reason (R): In the factory, the safety scrubber chimneys, filled with the detoxifying solution failed to function.
Ans. (c)

14. Assertion (A): After removal of parathyroids in lizards the blood calcium level rises rapidly.
Reason (R): Parathyroids regulate the level of calcium in blood.
Ans. (d)

15. Assertion (A): Linoleic acid and linolenic acid are essential polyunsaturated fatty acids.
Reason (R): Linoleic acid and linolenic acid are biosynthesized in human beings.
Ans. (c)

16. Assertion (A): As a fuel, coal releases two-thirds more carbon dioxide per unit of energy than floes gasoline.
Reason (R): Coal is largely carbon, whereas gaso-line contains more hydrogen.
Ans. (a)

17. Assertion (A): In pearl oyster, it is the necre, which forms the pearl.
Reason (R): Necre is secreted continuously by the edge of the mantle.
Ans. (b)

18. Assertion (A): Queen bee after mating produces both fertilized and unfertilized eggs.
Reason (R): Fertilized eggs produce queen and drones (males), whereas unfertilized eggs are eaten up. by the workers.
Ans. (c)

19. Assertion (A): Puffs in the polytene chromosomes are the sites of gene transcription.
Reason (R): DNA unfolds into open loop to facilitate RNA synthesis in the puff.
Ans. (a)

20. Assertion (A): Enlargement of spleen in a malarial patient is due to hemorrhage of arteries.
Reason (R): Infective states of Plasmodium are responsible for causing excessive proliferation of erythrocytes.
Ans. (d)

21. Assertion (A): Miracidium larva of Fasciola is endowed with cilia, penetration gland and apical gland.
Reason (R): The structure of miracidium is best adapted to penetrate into the liver and gall-bladder of sheep.
Ans. (c)

22. Assertion (A): A cell placed in an isotonic solution shows no change in size or volume.
Reason (R): Isotonic solutions have the same chemical composition as the cell cytoplasm.
Ans. (c)

23. Assertion (A): Cardiac muscle cells contain much large amounts of RNA than pancreatic cells.
Reason (R): High-protein-producing cells contain larger amount of RNA in comparison to low protein producing cells.
Ans. (d)

24. Assertion (A): Responses mediated by peptide hormones such as insulin are relatively slow.
Reason (R): The polypeptide hormones are rapidly removed from the blood by hydrolytic enzymes.
Ans. (c)

25. Assertion (A): Myoglobin bears an iron-containing haem group capable of combining reversibly with oxygen.
Reason (R): Myoglobin is made up of a monomeric polypeptide chain without a tertiary structure.
Ans. (c)

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pgt biology and Botany

pgt biology

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Free Biology Questions

Botany

1. Morphogenesis in plants is controlled by

(1) Auxins

(2) Gibberellins

(3) Cytokinins

(4) Abscisic acid

Ans. (4)

2. The non-auxin herbicide which is used to kill broad leaved plants in grass lawns is:

(a) Diquat

(b) Dinitrophenol

(c) Dalapon

(d) Dicamba

Ans. (c)

3. In tissue culture:

(a) Normal cells behave as cancer cell.

(b) Normal cells behave as normal cells

(C) Cancer cells behave as normal cells

(d) Cancer cells form callus

Ans. (a)

4. The plants of Cladophora crispata occur as:

(a) Epiphyte

(b) Endophyte

(c) Endozoic

(d) Epizoic

Ans. (d)

5. Which one of the following ratio is constant DNA of a species?

(a) A+T/G+C

(b) A+G/T+C

(c) A+C/T+G

(d) A+U/T+G

Ans. (a)

6. Mycorrhiza is:

(a) Association of root and bacteria

(b) Association of root and fungi

(c) Association of root and algae

(d) Parasitic root

Ans. (b)

Direction: In the following questions more than one of the answers given may be correct. Select the correct answers and mark it according to the code.

Codes:

(1) 1, 2 and 3 are correct

(2) 1 and 2 are correct

(3) 2 and 4 are correct ‘

(4) 1 and 3 are correct

7. Pollen tube of Cycas acts

(1) As an agent for carrying male. Gamete to the egg

(2) As a haustorium

(3) As endosperm

(4) As female cone

Ans. (2)

8. Which of the following conditions are necessary for the growth of the moulds, Mucor or Penicillium?

(1) Warmth

(2) Carbohydrate

(3) Water

(4) Light

Ans. (1)

9. Which of the following characteristics are associated with halophytes plants?

(1) Presence of pneumatophores

(2) Leaves and stem have hairy and waxy covering

(3) Shows viviparous germination

(4) Leaves show Heterophilly

Ans. (4)

10. The characteristic feature of leghaemoglobin are

(1) It is a source of energy

(2) It is a pinkish colour pigment found in nodules

(3) Activated by the presence of Mg²⁺ ions

(4) It protects nitrogen fixing enzyme nitrogenase from oxygen

Ans. (3)

11. Cyathium is characterized by

(1) Single female flower surrounded by many male flowers

(2) As involucres of bracts enclosing all the flowers

(3) Fleshy inflorescence axis with a pear shaped cavity inside

(4) Single male flower surrounded by many female flowers

Ans. (2)

12. Parietal placentation is found in the members of

(1) Family Cucurbitaceae

(2) Family Solanaceae

(3) Family Brassicaceae

(4) Family leguminosae

Ans. (4)

13. Which of the following is true regarding Guttation?

(1) Occurs through stomata

(2) Occurs through hydathodes

(3) Loss of pure water

(4) Occurs mostly during night and early morning

Ans. (3)

14. Which of the following statements are true for complementary genes?

(1) Both the genes interact to produce a complementary new trait

(2) Pair of nonallelic genes

(3) The F₂ ratio is generally 9: 7

(4) The F₂ ratio is generally 9: 3: 4

Ans. (1)

15. Coenzymes

(1) Act as a donor of groups of atoms added to the substrate

(2) Act as an acceptor of groups of atoms removed from the substrate

(3) Can not be easily separated from apoenzyme

(4) Do not act as prosthetic group

Ans. (2)

16. Suckers are

(1) Formed from the internodes of underground stem

(2) Formed from the node of underground stem

(3) Roots which are formed from the upper portion of nodes

(4) Roots which are formed from the lower portion of nodes

Ans. (3)

17. Non-cyclic photophosphorylation produces

(1) NADPH

(2) ATP and O₂

(3) ATP only

(4) O₂ only

Ans. (2)

18. C₄ pathway occurs

(1) Only in monocots

(3) In most of the dicats

(2) In monocots

(4) In few dicots

Ans. (3)

19. Link between glycolysis, Krebs’ cycle and ?-oxidation of fatty acid or carbohydrate and fat metabolism is

(1) Acetyl CoA

(2) A compound formed by oxidative de-carboxylation

(3) A 2-carbon compound

(4) oxaloacetic acid

Ans. (1)

20. The enzymes taking part in recombinant DNA technology are

(1) Restriction Endonuclease

(2) Ligase

(3) Reverse transcriptase

(4) Phosphates

Ans. (2)

21. The mode of asexual reproduction in bacteria are

(1) Formation of gametes

(2) Endospore formation

(3) Conjugation

(4) Zoospores formation

Ans. (3)

22. Acid rain is caused by

(1) Sulphur dioxide

(2) Hydrogen chloride

(3) Nitrogen oxides

(4) Phosphates

Ans. (1)

23. Censer mechanism is found in

(1) Aristolochia

(2) Antlrrhinum

(3) Papaver

(4) Cletnatis

Ans. (1)

24. Aerenchyma is present in which of the following plants?

(1) Neptunia

(2) Potamogeton

(3) Bryophyllum

(4) Vallesneria

Ans. (3)

25. One internodes long phylloclade is found in

(1) Ruscus

(2) Opuntia

(3) Asparagus

(4) Calotropis

Ans. (4)

Zoology

1. Lymphoid tissue is found in:

(a) Thymus

(b) Tonsils

(c) Lymph nodes

(d) All of these

Ans. (d)

2. Most widely used bioweapon is:

(a) Bacillus subtilis

(b) Pseudomonas putida

(c) Bacillus anthracis

(d) None of the above

Ans. (c)

3. The vitamin which is essential for blood clotting is

(a) Vitamin-A

(b) Vitamin-B

(c) Vitamin-C

(d) Vitamin-K

Ans. (d)

4. The female genital pore of Pheretima posthuma located upon the segment?

(a) 14^th

(b) 16^th

(c) 18^th

(d) 15^th

Ans. (a)

5. Polyp phase is absent in:

(a) Hydra

(b) Aurelia

(c) Physalia

(d) Obelia

Ans. (b)

6. In frog heart, there are cardiac muscles which consist of fibres called

(a) Purkinje fibres

(b) Myonemes

(c) Telodendria

(d) Columnae camae

Ans. (a)

7. Malpighian tubules are:

(a) Excretory organs of insects

(b) Excretory organs of frog

(c) Respiratory organs of insects

(d) Endocrine glands of insects

Ans. (a)

8. Pacemaker is:

(a) AV node

(b) SA node

(c) Bundle of His

(d) Purkinje fibres

Ans. (b)

9. LH and FSH are collectively called:

(a) Oxytocin

(b) Somatotrophins

(c) Luteotrophic

(d) Gonadotrophins

Ans. (d)

10. Who is known as “father of Endocrinology”?

(a) R.H. Whittaker

(b) Pasteur

(c) Einthoven

(d) Thomas Addison

Ans. (d)

11. Which of the following provides most evident proof of evolution?

(a) Fossils

(b) Morphology

(c) Embryo

(d) Vestigial organs

Ans. (a)

12. In Mollusca, eye is present over a stalk, called:

(a) Ostractum

(b) Operculum

(c) Ommatophores

(d) Osphradium

Ans. (c)

13. Among the following, colonial insects are:

(a) Locusts

(b) Mosquitoes

(c) White ants

(d) Bed bug

Ans. (c)

14. In Ascaris, the coelom is:

(a) Schizocoelom

(b) Pseudocoelom

(c) True coelom

(d) Haemocoelom

Ans. (b)

15. ‘Turbellarians’ are free living:

(a) Nematodes

(b) Cestodes

(c) Flat worms

(d) Trematodes

Ans. (c)

16. The characteristic larva of phylum ‘Coelenterata’ is:

(a) Planula

(b) Cysticercus

(c) Rhabdiform

(d) Wriggler

Ans. (a)

17. Podocytes are the cells, present in:

(a) Cortex of nephron

(b) Inner wall of Bowman4s capsule

(c) Outer wall of Bowman s capsule

(d) Wall of glomerular capillaries

Ans. (b)

18. In rabbit, head of epididymis present at the head of the testis is called:

(a) Vas deferens

(b) Cauda epididymis

(c) Gubernaculum

(d) Caput epididymis

Ans. (d)

19. Tendons and ligaments are specialized types of:

(a) Nervous tissue

(b) Muscular tissue

(c) Epithelial tissue

(d) Fibrous connective tissue

Ans. (d)

20. In blood, CO₂ is transported majorly as:

(a) Sodium carbonate

(b) Carboxyhaemoglobin

(c) Bicarbonate

(d) CO₂ as such

Ans. (c)

21. Animals undergoes inactive stage during winter, is known as

(a) Aestivation

(b) Hibernation

(c) Adaptation

(d) Acclimatization

Ans. (b)

22. Kupffer cells are present in:

(a) Liver

(b) Small intestine

(c) Pancreas

(d) Thyroid gland

Ans. (a)

23. The embryo at 16 celled stages is known as:

(a) Morula

(b) Gastrula

(c) Blastula

(d) Blastomere

Ans. (a)

24. Contractile vacuole in protozoan Amoeba is meant for:

(a) Respiration

(b) Excretion

(c) Locomotion

(d) Osmoregulation

Ans. (d)

25. In which of the following, putrefying bacteria is present?

(a) Intestine

(b) Colon

(c) Stomach

(d) Liver

Ans. (a)

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Posted in: Biology , botany , Question and Answers , quiz , test , Zoology