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

Question # 1

Write two application of polymerase chain reactions.

Ans 1: Two applications of polymerase chain reactions are as follows:
Ans 2: i) To diagnose viral infections,genetic disorder and cancer
ii) In forensic laboratories to identify criminals.

Question # 2

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 # 3

Define genetic code.

Ans 1: Genetic code is combination of three nucleotides,which specify a particular amino acid.

Question # 4

What is epistasis?Ho it differs from dominance?

Ans 1: Epistasis: An effect caused by a gene or gene pair at one locus interferes with or hides the effect caused by another gene or gene pair at another locus,such a phenomenon of gene interaction is called epistasis.
Epistasis must not be confused with dominance.
Ans 2: Dominance: Dominance is the relationship between alleles of the same gene occupying the same locus,but epistasis is the interaction between different genes occupying different loci.

Question # 5

What are biorhythms and diurnal rhythms?

Ans 1: Biorhythms are the biological activities of living organisms which are performed at regular intervals are called biorhythms.
Diurnal rhythms are the biological activities of organisms which are performed during one day 0r 24 hours.

Question # 6

What are Xerophytes?Give its examples.

Ans 1: Plant which grow under drought or in extreme shortage of water theses plants are called xerophytes. E.g, Cacti, Opuntia, Calatropis.

Question # 7

What are root nodules?Give their importance.

Ans 1: Root nodules are present in leguminous plants which contains bacteria.Importance is that these nodules contain nitrogen fixing bacteria which fix the nitrogen and supply it to the plant and play an important role in plant growth.

Question # 8

Define crossing over.Give its significance.

Ans 1: It is exchange of segments of chromosomes between non sister chromatids. Its significance is that,it provides raw material for evolution and also from new recombination of genes.

Question # 9

Define foliose lichens with one example. OR What is foliose lichen stage?Give an example.

Ans 1: In this stage the lichens are just crumpled leaves attached at one point.It produces shade to the crustose lichens as a result of which their growth is reduced.Examples are Dermatocarpon,Permellia.

Question # 10

What is flame cell Why it is called so?

Ans 1: Flame cell is the part of excretory system of planaria.It is called flame cell because it has tuft of cilia, which looks like flickering flame of candle.

Question # 11

Differentiate between primary growth and secondary growth in plant.

Ans 1: Primary growth: occur due to the activity of apical meristem which results increase in length or height of plant.
Ans 2: Secondary growth: Of plants occur due to activity of cambium and it results increase in girth of plant.

Question # 12

Give two functions of cytokinin hormone.

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

Question # 13

Differentiate between multiple alleles and polygenes..

Ans 1: Multiple alleles: If a gene has more than two alternate forms these are called multiple alleles.For example alleles for ABO blood group. E.g,alleles for ABO blood group.
Ans 2: Polygenes: When a continuously varying trait is controlled by alleles for two or more than two different gene pairs found at different loci,all influencing the same trait in an additive way,such genes are called polygenes, e.g,genes for controlling skin and eye colour in human.

Question # 14

Name two sexually transmitted disease and their control.

Ans 1: Genital herpes and AIDS. These sexually transmitted diseases can be controlled by avoiding sexual contact with affected person and adopting the hygienic conditions and also by taking medical treatment.

Question # 15

Write down four functions of auxin.

Ans 1: Function of auxin are
Ans 2: Auxin promote cell elongation
Ans 3: It promotes cell division in cambium
Ans 4: It can induce parthenocarpy
Ans 5: It promotes apical dominance

Question # 16

What are graminoids,in which biome they exist?

Ans 1: Gramonoids are grasses or grass like plants which are present in grass land ecosystem.

Question # 17

Write four similarities of nervous and chemical coordination.

Ans 1: Similarities are as follow
Ans 2: Both system help in co-ordination.
Ans 3: both are homoeostatic in function.
Ans 4: Both release chemical messenger in extracellular space of body.
Ans 5: Both systems synthesize chemical messengers

Question # 18

What is Hardy-Weinberg theorem.Give its equation.

Ans 1: It states that the frequencies of alleles and genotypes in a population remain constant over the generation unless acted upon by agents other than sexual recombination.
(P+q)²= P²+ q²+ 2pq

Question # 19

Differentiate between template and coding stands of DNA.

Ans 1: Template Strand: The strand of DNA which is transcribed is called template strand or antisense strand.
Ans 2: Coding Strand: The Strand of DNA which is not transcribed is called coding strand or sense strand.

Question # 20

What is layering in grassland?

Ans 1: Due to difference in height of grasses layering is formed.It is characteristic of grass land ecosystem.Three layers are formed.Tall grasses form first layer,mid high grasses form second layer and third is formed by short grasses.

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