Find the 12th Class Fsc Part 2 Short Questions Online Preparation Biology

Question # 1

Apomixes is a form of parthenogenesis.Discuss

Ans 1: In apomixes a diploid cell either from the nucellus or megaspore develops into a functional embryo in the absence of a male gamete. The rest of the ovule develops into seed and and ovary into fruit.
Ans 2: Parthenogenesis: Development of an egg without fertilization

Question # 2

What are effectors?Give example.

Ans 1: Effectors are the organs which show response after receiving message from the associative neurons via motor neurons.For example muscles and glands.

Question # 3

What is mycorrhiza?

Ans 1: It is a symbiotic association between the roots of higher plants and hyphae of the fungi is called mycorrhiza. Fungus provides nutrient to the plant and in turn it self get carbohydrates from the plant.

Question # 4

Give importance of photoperiodism in plants.

Ans 1: Photoperiodism plays an important role in flowering of plants in long and short day plants.

Question # 5

Differentiate between CNS and PNS

Ans 1: CNS Central nervous system consists of brain and spinal cord.
Ans 2: PNS Peripheral nervous system consists of nerves arising from brain (cranial nerves) and spinal cord(spinal nerves).

Question # 6

What are mutagens? Give one example.

Ans 1: In genetics,a mutagen is a physical or chemical agent that changes the genetic material,usually DNA of an organism and thus increases the frequency of mutations.
For Example: X-ray,ultraviolet radiations etc.

Question # 7

Explain testicular feminization syndrome.

Ans 1: Testicular feminization syndrome is a rare X linked recessive trait.Although the persons affected by this trait have a set of XY chromosome.Yet tfm gene on their X chromosome develops them physically into females.They have breast,female genitalia a blind vagina but no uterus,degenerated testis are also present in abdomen.Such individuals are happily married as female but are sterile.it is an androgen insensitivity syndrome.Male sex hormone testoterone has no effect on them.

Question # 8

What is universality of genetic code?

Ans 1: It mean it is same for all the organisms.Because of the universality of codon the genes can be transferred from one organism to another and successfully transcribed and translated in their new host.

Question # 9

What is pulvinus.

Ans 1: 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 # 10

Differentiate between phototactic and phototropic movement.

Ans 1: Phototactic is a type of tactic movement in which movement occurs in response of light stimulus.
Ans 2: Phototropic movement is a growth movement due to light stimulus.

Question # 11

What is meant by division of labour ?

Ans 1: Division of labour means a specific type of cells can perform a specific type of function.Like muscle cells contract and relax,glandular cells produce secretions, phloem can transport food.

Question # 12

Name the synthetic auxin used as selective weed killer.

Ans 1: 2-4D (2,4 Dichlorophenoxy acetic acid)is selective weed killer.

Question # 13

Give two characteristics of hormones.

Ans 1: hormones are porteins in nature.
Ans 2: They help in the co-ordination of the organisms by activating the target cells of the body.

Question # 14

Define mitotic apparatus. Or Give its functions.

Ans 1: Mitotic apparatus composed of spindle fibers,centriols and asters.Mitotic apparatus plays an important role in cell division and equal distribution of chromosomes during cell division.

Question # 15

Define Regeneration.Give one example.

Ans 1: The ability to regain or recover the lost part or injured part of the body is called regeneration.For Example if lobster loses its pincer claw a new claw regenerates.

Question # 16

Differentiate between food chain food web.

Ans 1: Food Chain: Process of eating and being eaten is called food chain.
Ans 2: Food web: Combination of different food chains is called food web.

Question # 17

Explain the term epinasty and hyponasty.

Ans 1: 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 # 18

Define probability.

Ans 1: It is the chance of an event to occur.

Question # 19

Give two functions of cytokinin hormone.

Ans 1: It inhibits primary root growth and promote opening of stomata.

Question # 20

Give effects of nicotine on blood vascular system and digestive system in man.

Ans 1: It increases the heart beat rate,blood pressure and digestive tract mobility Nicotine may induce vomiting and diarrhoea and even may cause water retention relation by kidneys.

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