12th Class Biology Chapter 2 Short Questions with Answers Solved

Question: 1

Explain the term epinasty and hyponasty.

Answer: 1

1-50

Epinasty: is show by leaves, petals etc.the upper surface of leaf in bud condition shows more growth as compared with lower surface.This leads to opening of buds.

Hyponasty: If growth in the lower surface of the leaf in bud condition is more than that of upper surface then buds remain close and it is called hyponasty.

Question: 2

Give classification of vertebral column.

Answer: 2

2-50

Vertebral column has been divided into four regions cervical regions has seven vertebrae, thoracic region has 12 vertebrae, lumber region hasnine vertebrae,pelvic region has two sets, sacrum and coccyx.Sacrum has five anterior fused vertebrae while coccyx has four posterior fused vertebrae.

Question: 3

Which tissues arise from vascular cambium?

Answer: 3

3-50

Secondary xylem, secondary phloem (wood),bark

Question: 4

How the muscle fatigue is resulted?

Answer: 4

4-50

When we do hard exercise, an aerobic respiration starts in the muscle and lactic acid is accumulated which results muscles fatigue.

Question: 5

Write down the mechanism of rapid movements of leaflets.

Answer: 5

5-50

When Mimosa (Touch me not) leaf is touched, it rapidly loss its turgor pressure due to exosmosis which results in closing of leaves.K⁺ Ions also play role in this movement.

Question: 6

What is turgor pressure?

Answer: 6

6-50

When water enters the cell of plant it reaches in the vacuole and it exerts pressure on the wall of the cell which is called turgor pressure.

Question: 7

Define Nutation.

Answer: 7

7-50

Zigzag movement of growing tips of vines along an object is called nutation.For example growing tip of climbing plants or vines show nutation.

Question: 8

Define phototactic movement and photonastic movement.

Answer: 8

8-50

Phototactic Movement: is a types of tactic movement in which movement occur in response to light stimulus. Photonastic Movements:that in which photoperiod is critical in opening and closing of flowers.

Question: 9

Differentiate between phototactic and phototropic movement.

Answer: 9

9-50

Phototactic is a type of tactic movement in which movement occurs in response of light stimulus.

Question: 10

What is pulvinus.

Answer: 10

10-50

These are the parenchymatous cell which are present at the base of petiole of some plants.They store water and play role in the opening and closing of leaves changing their turgor pressure.

Question: 11

Define secondary growth,give its significance.

Answer: 11

11-50

Secondary growth means increase in girth of root or stem(plant).

Significance: it form secondary xylem which act as wood.

Growth rings are formed which are helpful in calculating plant age.

Question: 12

Define geotropism.

Answer: 12

12-50

Response of plant parts to the gravity is called geotropism.Roots show positive geotropism and stem shows negative geotropism.

Question: 13

What are nastic movement?

Answer: 13

13-50

These are non directional movement of parts of plant in response to external stimuli.

Question: 14

Define collenchyma cells.

Answer: 14

14-50

Collenchyma cells have protoplast and lack secondary wall.They have angular thickening in their inner walls.They are living cells and give support to plant cells.

Question: 15

Define tactic movements.Give its one type.

Answer: 15

15-50

The movement of entire organism or cell ie,.locomotive due to external stimulus is called tactic movement.

Question: 16

Name two paired facial bones.

Answer: 16

16-50

The two paired facial bone are temporal and parietal bones.

Question: 17

Name bones of human pectoral girdle.

Answer: 17

17-50

Scapula, supra scapula and clavicle.

Question: 18

Write a brief note on tetany.

Answer: 18

18-50

It a disease caused by low calcium level in blood.It increases the excitability of neurons and results in loss of sensation,Muscle twitch and convolutions occur.if untreated the system progresses to spasm of larynx,respiratory paralysis and resulting death.

Question: 19

What is rigor mortis?

Answer: 19

19-50

After the death of a person, the ATP are reduced and cross bridges are not broken and muscles become stiff, this condition is known as rigor mortis.

Question: 20

Name the bones of pelvis Girdle.

Answer: 20

20-50

Ilium,Ischium and pubis.

Question: 21

State hematoma formation briefly.

Answer: 21

21-50

When bone breaks, bleeding occur and as a result haematoma formation occurs.Soon after bone cells deprived of food begin to die and the tissue at the fracture site becomes swollen and hence painful.

Question: 22

Differentiate between exoskeleton and endoskeleton.

Answer: 22

22-50

Endoskeleton: is advance form of skeleton.It is living skeleton and cause swift movement of animal with the help of muscles.It lies inside the body of animal.

Question: 23

Explain the ball and socket joints and give an example.

Answer: 23

23-50

Joints which can move or rotate in more than one plane are called ball and socket joints like shoulder and hip joint.

Question: 24

Name unpaired facial bones.

Answer: 24

24-50

Mendible and vomer are unpaired facial bones.

Question: 25

What is foramen triosseum?How it is formed?

Answer: 25

25-50

In birds the lifting action is possible because the tendon of the supra coracoid muscles pass through an opening called foramen triosseum formed between the scapula coracoid and clavicle bones is attached to the upper surface of the humerus.

Question: 26

Write the name of two bones of cranium.

Answer: 26

26-50

Bones of cranium include parietal and temporal bones.

Question: 27

Name any two parts of hind limb.

Answer: 27

27-50

Ilium and ischium.

Question: 28

What are disadvantages of exoskeleton?

Answer: 28

28-50

Disadvantages of exoskeleton are.

It restrict the growth of animal.
It is nonliving.it has to be shed periodically and new skeleton should be made.

Question: 29

Compare epicuticle and procuticle.

Answer: 29

29-50

Epicuticle: is the outer most layers.It is made up of waxy lipoprotein, so it is impermeable to water and serves as a barrier to microorganisms and insects.

Question: 30

Give two roles of vascular cambium.

Answer: 30

30-50

Vascular cambium performs secondary growth of plant.Secondary xylem is produced which act as wood and also give support to plant.It also produces annual rings by which we can calculate age of plant.

Question: 31

What are the characteristics of smooth muscles?

Answer: 31

31-50

Smooth muscle are non striated and involuntary as well as unbranched.They produces movement in body on concentration.

Question: 32

Give symptoms and causes of sciatica.

Answer: 32

32-50

It is characterized by stabbing pain radiating over the course of sciatic nerve.It is caused due to injury of proximal sciatic nerve,which might follow a fall,a herniated disc or improper administration of an injection in to the buttock.

Question: 33

Give two modifications in the exoskeleton of arthropods.

Answer: 33

33-50

Modification of exoskeleton in arthropods is as follow

Formation of sensilla (bristle), lenses and modification for gaseous exchange.

Question: 34

Give any two major functions of skeletal system in animals.

Answer: 34

34-50

It provides support and movement to the animal body.

Question: 35

What do you know about rickets?

Answer: 35

35-50

It is a disease of children with bowed bones of legs and deformed pelvis.It is caused by calcium deficiency in diet or deficiency of vitamin-D.it is treated by vitamin-D' fortified milk and exposing skin to sunlight to cure disorder.

Question: 36

Name the unpaired cranial bones.

Answer: 36

36-50

Ethmoid, frontal, occipital and sphenoid are unpaired cranial bones.

Question: 37

What are the causes of herniation? Discuss.

Answer: 37

37-50

Sever or sudden physical trauma to spines may result in herniation.The herniated disc usually involves the rupture of annulus fibrosus followed by protrusion of the spongy nucleus pulposus.

Question: 38

Described pelvic and pectoral girdle in human skeleton.

Answer: 38

38-50

Pelvic girdle attaches the hind limbs to the vertebral column.it consists of two coxal bones.Each of which is formed by the fusion of three bones ilium,ischium and pubic.Pectoral girdle comprises scapula, supra scapula and clavicle.Clavicle connects scapula with sternum.

Question: 39

Give two character of smooth muscles.

Answer: 39

39-50

Smooth muscles are long & spindle shape with each containing a single nucleus. It has no striations.

Question: 40

Name different bones of Hind Limb.

Answer: 40

40-50

Bones of hind limb are femur, tibia, fibula, tarsals, metatarsals, phalanges.

Question: 41

Give the name of hormones which are involved in epinasty and hyponasty.

Answer: 41

41-50

Epinasty is due to auxins and hyponasty is due to gibberellins.

Question: 42

Define turgor and osmotic pressure.

Answer: 42

42-50

Turgor pressure is pressure exerted by the water on the walls of the vacuole while the osmotic pressure due to presence of solute in the water.It is also called solute potential.

Question: 43

Define aerofoils.

Answer: 43

43-50

An aerofoil is any smooth surface which moves through the air at an angle to the air stream for example wing of a bird act as aerofoil.

Question: 44

Define tonoplast,give its function as well.

Answer: 44

44-50

The wall of vacuole is called tonoplast, it is single membrane.It maintains the turgor pressure and solute concentration.

Question: 45

What is caused and symptoms of Rickets?

Answer: 45

45-50

Rickets is caused by deficiency of calcium or vitamin D in diet.Its symptoms include children with bowed legs and deformed pelvis.

Question: 46

Give two difference between animals and plants movements.

Answer: 46

46-50

Pants show movement but remain fixed at their position.Their movement is shown but change in their growth.Animals show their movement by changing their position;their movement does not involve any growth.

Question: 47

Characterize digitigrades animals.

Answer: 47

47-50

Animals which walk on the tips of their digits only are called digitigrades.They run faster than plantigrade animals.In these animals first digit usually reduces or completely lost as in rabbit, rodents.

Question: 48

Define Plantigrades with example.

Answer: 48

48-50

Animals which walk on the sole.When they walk their sole and toes touch the ground are called plantigrades. E.g., human, bear and monkey.

Question: 49

Characterize collenchyma cells.

Answer: 49

49-50

Collenchyma are living cells which lack secondary wall with angular thickenings.It provides support to the young plants.

Question: 50

What is callus and its role?

Answer: 50

50-50

Callus is a mass of undifferentiated cells.It heals the wound of plant.

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12th Class Chapter 2 Biology Short Questions

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