biology MCQs - 11th class Chapter 14 Mcqs

1

The process by which water molecules move from a region of higher concentration to a region of lower concentration through a partially permeable membrane is called?

A

Diffusion

B

Osmosis

C

Active Transport

D

Endocytosis

2

Which structures are the primary sites for the uptake of water and minerals in plants?

A

Stem

B

Leaves

C

Root hairs

D

Flowers

3

The pathway for water and solutes that involves the system of adjacent cell walls continuous throughout the plant root is called?

A

Symplast pathway

B

Vacuolar pathway

C

Apoplast pathway

D

Transmembrane pathway

4

What is the water potential ($ψ_w$) of pure water by definition?

A

100

B

0

C

-100

D

1

5

The cohesion-tension theory explains the upward flow of water from roots to leaves. What provides the 'tension'?

A

Root pressure

B

Adhesion

C

Transpiration pull

D

Imbibition

6

The loss of liquid water through water-secreting glands or hydathodes is known as?

A

Transpiration

B

Bleeding

C

Exudation

D

Guttation

7

Which type of transpiration accounts for about 90% of the total water loss from a plant?

A

Cuticular transpiration

B

Lenticular transpiration

C

Stomatal transpiration

D

Bark transpiration

8

According to the influx of K+ ions hypothesis, what happens when potassium ions are actively transported into guard cells?

A

Stomata close

B

Guard cells become flaccid

C

Stomata open

D

Water leaves the guard cells

9

Which hormone, released by wilting leaf cells, causes stomata to close?

A

Auxin

B

Gibberellin

C

Cytokinin

D

Abscisic acid

10

What is the most widely accepted theory for the transport of organic solutes in the phloem?

A

Diffusion theory

B

Pressure-flow theory

C

Active transport theory

D

Cohesion-tension theory

11

What is the primary sugar transported in the phloem?

A

Glucose

B

Fructose

C

Sucrose

D

Maltose

12

In complex animals, what is the contractile pumping device in the circulatory system?

A

Blood vessel

B

Heart

C

Artery

D

Vein

13

Which animals have an open circulatory system?

A

Earthworms and vertebrates

B

Annelids and squids

C

Arthropods and most molluscs

D

Echinoderms and humans

14

In the heart of fishes, which chamber receives deoxygenated blood from the body?

A

Atrium

B

Ventricle

C

Sinus venosus

D

Conus arteriosus

15

How many chambers are there in an amphibian heart?

A

Two

B

Three

C

Four

D

One

16

In mammals and birds, the heart is four-chambered, which completely separates?

A

Atria from ventricles

B

Pulmonary and systemic circuits

C

Oxygenated and deoxygenated blood

D

Arteries from veins

17

What percentage of blood volume is typically plasma in a normal person?

A

45%

B

90%

C

55%

D

10%

18

Which plasma protein is involved in blood clotting?

A

Albumin

B

Globulin

C

Fibrinogen

D

Immunoglobulin

19

What is the average life span of a human red blood cell?

A

One week

B

One month

C

Four months

D

One year

20

Which type of white blood cell produces antibodies?

A

Neutrophil

B

Basophil

C

Monocyte

D

Lymphocyte

21

Fragments of which cells form platelets?

A

Erythrocytes

B

Leucocytes

C

Megakaryocytes

D

Myelocytes

22

A genetic condition characterized by abnormal hemoglobin and enlargement of the spleen is called?

A

Leukemia

B

Oedema

C

Thalassaemia

D

Atherosclerosis

23

The valve between the right atrium and the right ventricle of the human heart is the?

A

Bicuspid valve

B

Semilunar valve

C

Aortic valve

D

Tricuspid valve

24

Where does the cardiac cycle's electrical impulse originate?

A

Atrioventricular (AV) node

B

Sinoatrial (SA) node

C

Purkinje fibers

D

Bundle of His

25

What condition involves the deposition of hard yellow plaque in the arteries?

A

Arteriosclerosis

B

Atherosclerosis

C

Hypertension

D

Thrombus

26

Which blood vessels have walls that are only one cell thick?

A

Arteries

B

Veins

C

Capillaries

D

Arterioles

27

What is the fluid called once it enters the lymph capillaries?

A

Plasma

B

Serum

C

Interstitial fluid

D

Lymph

28

Which lymphoid organ filters blood, destroying foreign particles and aged red blood cells?

A

Thymus

B

Tonsils

C

Spleen

D

Lymph node

29

Immunity achieved through vaccination is an example of?

A

Naturally induced active immunity

B

Artificially induced active immunity

C

Naturally induced passive immunity

D

Artificially induced passive immunity

30

What is a foreign substance, often a protein, that stimulates the formation of antibodies?

A

Antibody

B

Antigen

C

Antitoxin

D

Lymphocyte

31

What term describes the shrinkage of protoplast due to the exosmosis of water?

A

Turgidity

B

Plasmolysis

C

Deplasmolysis

D

Incipient plasmolysis

32

What is the attraction among water molecules that holds them together in a column within the xylem?

A

Adhesion

B

Tension

C

Cohesion

D

Capillarity

33

In the pressure-flow theory, an exporting organ like a mature leaf is known as a?

A

Sink

B

Source

C

Transporter

D

Reservoir

34

The heart of a fish functions as a?

A

Single circuit heart

B

Double circuit heart

C

Triple circuit heart

D

Partial circuit heart

35

What is the normal pH of human blood?

A

7.0

B

6.8

C

7.4

D

8.0

36

Neutrophils and monocytes are primarily involved in which process?

A

Producing antibodies

B

Blood clotting

C

Phagocytosis

D

Carrying oxygen

37

The 'lubb' sound of the heartbeat is caused by the closing of which valves?

A

Semilunar valves

B

Aortic and pulmonary valves

C

Tricuspid and bicuspid valves

D

Thebesian valves

38

What is the primary function of the lymphatic system's lacteals in the villi?

A

Absorb proteins

B

Absorb carbohydrates

C

Absorb large fat globules

D

Absorb water

39

Cell-mediated response, which involves the rejection of foreign tissues, is primarily carried out by?

A

B-cells

B

T-cells

C

Plasma cells

D

Macrophages

40

In which part of the circulatory system is the blood flow the slowest?

A

Aorta

B

Arteries

C

Veins

D

Capillaries

41

Most of the minerals enter the root hairs along with water in a process known as?

A

Bulk flow

B

Simple diffusion

C

Facilitated diffusion

D

Osmosis

42

Mycorrhizal fungi primarily help the plant in the uptake of which mineral?

A

Nitrogen

B

Potassium

C

Phosphorus

D

Calcium

43

The process where certain plants show a flow of sap from a cut surface is called?

A

Guttation

B

Transpiration

C

Bleeding

D

Imbibition

44

In dorsiventral leaves, stomata are typically confined to the?

A

Upper epidermis only

B

Lower epidermis only

C

Both upper and lower epidermis

D

Leaf margins

45

Which part of an aphid is used to puncture a sieve tube to collect phloem sap?

A

Legs

B

Antennae

C

Stylets

D

Mandibles

46

In the open circulatory system of a cockroach, the blood is called?

A

Plasma

B

Hemolymph

C

Lymph

D

Serum

47

What is the term for the presence of excess fluid in the body tissues?

A

Leukemia

B

Oedema

C

Thalassaemia

D

Cyanosis

48

The wall of the left ventricle is thicker than the right ventricle because it?

A

Pumps blood to the lungs

B

Pumps blood to the entire body

C

Receives deoxygenated blood

D

Is smaller in size

49

A solid mass or plug of blood constituents (clot) in a blood vessel is called a?

A

Embolus

B

Thrombus

C

Plaque

D

Hemorrhage