biology MCQs - 12th class Chapter 02 Mcqs

1

Which cells provide support to baby plants through turgor pressure?

A

Sclerenchyma

B

Parenchyma

C

Xylem

D

Phloem

2

The major mechanical stress in most terrestrial plants is imposed by?

A

Gravity

B

Water

C

Wind

D

Sunlight

3

In woody stems, what is the inactive, non-conducting wood called?

A

Sapwood

B

Cork

C

Heartwood

D

Cambium

4

The movement of an entire cell or organism due to an internal stimulus is called?

A

Tactic movement

B

Tropic movement

C

Nastic movement

D

Growth movement

5

Sleep movements in bean plants are due to changes in?

A

Light intensity

B

Temperature

C

Turgor pressure

D

Hormone concentration

6

The opening of buds due to more growth on the upper surface of a leaf is known as?

A

Hyponasty

B

Nutation

C

Epinasty

D

Tropism

7

The movement of plant parts in response to the stimulus of touch is called?

A

Phototropism

B

Geotropism

C

Chemotropism

D

Thigmotropism

8

Which hormone plays a major role in phototropism?

A

Gibberellin

B

Cytokinin

C

Auxin

D

Abscisic acid

9

Which type of skeleton is found in cnidarians and annelids?

A

Exoskeleton

B

Endoskeleton

C

Hydrostatic skeleton

D

Cartilaginous skeleton

10

The outer layer of an arthropod's exoskeleton, composed of waxy lipoprotein, is the?

A

Procuticle

B

Endocuticle

C

Epicuticle

D

Exocuticle

11

The process of periodically shedding the exoskeleton in arthropods is called?

A

Moulting

B

Sclerotization

C

Metamorphosis

D

Regeneration

12

What hormone controls the process of ecdysis?

A

Gibberellin

B

Ecdysone

C

Thyroxine

D

Insulin

13

Which cells are responsible for dissolving bone tissue?

A

Osteoblasts

B

Osteocytes

C

Chondrocytes

D

Osteoclasts

14

The living cells of cartilage are called?

A

Osteocytes

B

Chondrocytes

C

Fibroblasts

D

Stem cells

15

How many bones make up the cranium in the human skull?

A

6

B

8

C

10

D

14

16

The first two cervical vertebrae are named?

A

Atlas and Axis

B

Sacrum and Coccyx

C

Tibia and Fibula

D

Radius and Ulna

17

The lower two pairs of ribs that do not attach to the sternum are called?

A

True ribs

B

False ribs

C

Floating ribs

D

Costal ribs

18

The hip joint is an example of which type of joint?

A

Hinge joint

B

Pivot joint

C

Ball and socket joint

D

Fibrous joint

19

A genetic condition where the palatine processes fail to fuse is known as?

A

Microcephaly

B

Arthritis

C

Cleft palate

D

Osteoporosis

20

Osteoporosis in aged women is mostly related to a decreased level of which hormone?

A

Progesterone

B

Testosterone

C

Estrogen

D

Thyroxine

21

Rickets in children is caused by a deficiency of calcium or?

A

Vitamin A

B

Vitamin B

C

Vitamin C

D

Vitamin D

22

What is the inner semi-fluid part of an intervertebral disc called?

A

Annulus fibrosus

B

Nucleus pulposus

C

Synovial fluid

D

Hematoma

23

Which type of muscle is described as visceral, non-striated, and involuntary?

A

Skeletal muscle

B

Cardiac muscle

C

Smooth muscle

D

Tendon muscle

24

The smallest contractile unit of a muscle fiber is the?

A

Myofibril

B

Sarcomere

C

Myofilament

D

Z-line

25

The thick filaments in a myofibril are composed of which protein?

A

Actin

B

Troponin

C

Tropomyosin

D

Myosin

26

According to the sliding filament model, which zone disappears during muscle contraction?

A

A-band

B

I-band

C

H-zone

D

Z-line

27

What ion is essential for binding to troponin to expose the binding sites on actin?

A

Sodium (Na+)

B

Potassium (K+)

C

Calcium (Ca++)

D

Magnesium (Mg++)

28

The condition where the body becomes stiff after death due to unbroken actin-myosin bridges is?

A

Tetany

B

Cramp

C

Rigor mortis

D

Fatigue

29

A state of physiological inability of a muscle to contract, often due to an ATP deficit, is called?

A

Tetany

B

Muscle fatigue

C

Rigor mortis

D

Spasm

30

The disease caused by low calcium in the blood, leading to muscle twitches and convulsions, is?

A

Cramp

B

Tetany

C

Tetanus

D

Arthritis

31

Non-elastic connective tissues that attach muscles to bones are called?

A

Ligaments

B

Tendons

C

Cartilage

D

Fibers

32

What is the relationship called where muscles work against each other at a joint?

A

Synergism

B

Antagonism

C

Flexion

D

Extension

33

Locomotion in Euglena is primarily carried out by a?

A

Cilium

B

Flagellum

C

Pseudopodium

D

Myoneme

34

The movement in Paramecium is described as?

A

Amoeboid movement

B

Euglenoid movement

C

Ciliary movement

D

Jet propulsion

35

Jellyfish move by a mechanism known as?

A

Jet propulsion

B

Accordion-like movement

C

Ciliary movement

D

Flagellar movement

36

Earthworm locomotion involves the use of muscles and?

A

Cilia

B

Flagella

C

Setae

D

Tube feet

37

Starfish move with the help of?

A

Arms

B

Radial canals

C

Tube feet

D

Tentacles

38

The structure that helps bony fish maintain buoyancy is the?

A

Gills

B

Swim bladder

C

Lateral line

D

Caudal fin

39

Mammals that walk on their soles, like humans and bears, are described as?

A

Digitigrade

B

Unguligrade

C

Plantigrade

D

Bipedal

40

The skeleton of a bird is made lighter by?

A

Having fewer bones

B

Smaller bones

C

Large air spaces in bones

D

Being made of cartilage

41

What is the tough, leathery polysaccharide found in the procuticle of arthropods?

A

Lignin

B

Pectin

C

Chitin

D

Cellulose

42

The membrane that bounds the vacuole in a plant cell is called?

A

Tonoplast

B

Sarcolemma

C

Plasmalemma

D

Cell membrane

43

The growth of roots towards water is an example of?

A

Positive phototropism

B

Negative geotropism

C

Positive hydrotropism

D

Negative thigmotropism

44

The human vertebral column consists of how many vertebrae?

A

26

B

30

C

33

D

35

45

The muscles of the heart are known as?

A

Skeletal muscles

B

Smooth muscles

C

Voluntary muscles

D

Cardiac muscles

46

Which protein in thin filaments covers the myosin-binding sites when a muscle is at rest?

A

Actin

B

Troponin

C

Tropomyosin

D

Myosin

47

The fusion of the anterior five vertebrae in the pelvic region forms the?

A

Coccyx

B

Sacrum

C

Ilium

D

Pubis

48

Pain radiating over the course of the sciatic nerve is known as?

A

Spondylosis

B

Arthritis

C

Sciatica

D

Rickets

49

The upward and inward bending of tulip petals at night is an example of?

A

Photonasty

B

Thermonasty

C

Nyctinasty

D

Haptonasty

50

A cilium consists of how many peripheral double fibrils?

A

7

B

8

C

9

D

10