Get the 12th Class Fsc Biology Online Preparation for chapter 22 (Variation and Genetics)

Question # 1

Explain genic system for determination of sex.

Ans 1: Many species of eukaryotic micro-organisms like yeast do not have sex chromosomes.These depend on genic system for determination of sex.In this system the sexes are specified by simple allelic differences at small number of gene loci.

Question # 2

Differentiate between homozygous and heterozygous.

Ans 1: Homozygous: If alleles of a gene pair are in similar from they are called homozygous.
Ans 2: Heterozygous: If the alleles of a gene pair are in different from they are called heterozygous.

Question # 3

What is XO-XX mechanism of sex determination?

Ans 1: This pattern of Inheritance is found in grasshopper and protenor bug.Male is XO because male has one x chromosomes,the other x chromosomes is missing and female is xx,it is homogametic because it forms all gametes of same type with one X chromosome.Male is heterogametic because it forms two types sperms: half sperms have X chromosomes and other half are without X chromosomes.
When sperm with X chromosomes is fused with an egg having X chromosomes female offspring is produced and when sperms without X chromosomes is fused with egg then male offspring will be produced.

Question # 4

Differentiate between tritanopia and deutranopia.

Ans 1: Tritanopia: Tritanopia is blue colour blindness.
Ans 2: Deuteranopia: Deuteronopia is green blindness.

Question # 5

Define probability.

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

Question # 6

Differentiate between quantitative and qualitative variations.

Ans 1: Quantitative variations: In Qualitative variations difference is small and less striking.Many traits like skin color,height and weight exhibit continuous quantitative variation.
Ans 2: Qualitative variations: In qualitative variations differences are large and more obvious,some traits like pea seed shape show discontinuous qualitative variations with two sharply distinct phenotypes like round and wrinkled.

Question # 7

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 # 8

What is law of segregation?

Ans 1: The two coexisting alleles for each trait in an individual segregate from each other at meiosis, so that each gamete has only one the two alleles.Alleles unite again random fertilization of gametes when zygote is formed.

Question # 9

What is dominance?Discuss over dominance.

Ans 1: Dominance is a physiological effect of an allele over its partner allele on the same locus.
Over dominance: This relation is very interesting because the over dominant heterozygote exceed in quantity than phenotypic expression of both the homozygotes. In fruit fly Drosophila the heterozygote(W⁺/w) has more quantity of florescent pigments in eyes than wild (w⁺/w^{+) or white eye (w/w) homozygote.}

Question # 10

What is test cross? Give its significance?

Ans 1: Test cross is a cross used to test the genotype of an organism showing dominant phenotype.
Significance of test cross is that we can know the genotype of an organism

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12th Class Fsc Biology Online Preparation for chapter 22 (Variation and Genetics)

Online Short Questions For Chapter 8 "12th Class Biology Chapter 22 Short Questions Preparation "

Biology - 12th Class Biology Chapter 22 Short Questions Preparation

Explain genic system for determination of sex.

Differentiate between homozygous and heterozygous.

What is XO-XX mechanism of sex determination?

Differentiate between tritanopia and deutranopia.

Define probability.

Differentiate between quantitative and qualitative variations.

What is epistasis?Ho it differs from dominance?

What is law of segregation?

What is dominance?Discuss over dominance.

What is test cross? Give its significance?

Prepare Complete Set Wise Questions For Chapter 8 "12th Class Biology Chapter 22 Short Questions Preparation "

Set 1

Set 2

Set 3

Set 4

Set 5

Set 6

12th Class Biology Chapter 22 Short Questions Preparation - Set 1

Explain genic system for determination of sex.

Differentiate between homozygous and heterozygous.

What is XO-XX mechanism of sex determination?

Differentiate between tritanopia and deutranopia.

Define probability.

Differentiate between quantitative and qualitative variations.

What is epistasis?Ho it differs from dominance?

What is law of segregation?

What is dominance?Discuss over dominance.

What is test cross? Give its significance?

12th Class Biology Chapter 22 Short Questions Preparation - Set 2

What is epistasis?Ho it differs from dominance?

What is XO-XX mechanism of sex determination?

What is erythroblastosis foetalis?

Define recombination frequency.Give an example.

What is type II diabetes or NIDDM?

What are sex influenced traits?Give an example.

Differentiate between homogametic and heterogametic organism.

How sex is determined in yeast?

Explain genic system for determination of sex.

What is beanbag genetics? Explain.

12th Class Biology Chapter 22 Short Questions Preparation - Set 3

Give significance of test cross.

How sex is determined in plants?

What is dominance?Discuss over dominance.

Differentiate between dominant and recessive traits.

What do you known about protanopia and tritanopia?

How sex is determined in yeast?

How does ABO incompatibility protect the developing baby against Rh-

Define co-dominance.

What are multiple alleles,give its example?

Explain genic system for determination of sex.

12th Class Biology Chapter 22 Short Questions Preparation - Set 4

Assign the sex of the human having XO,XXX,XXY and XYY chromosomes.

Give significance of test cross.

What are multiple alleles,give its example?

What is Mody?Write its causes.

Compare between epistasis and poleiotropy.

Differentiate between gene and allele.

How does ABO incompatibility protect the developing baby against Rh-

Define co-dominance.

What is type II diabetes or NIDDM?

What is XO-XX mechanism of sex determination?

12th Class Biology Chapter 22 Short Questions Preparation - Set 5

Differentiate between homozygous and heterozygous.

What is Bombay Phenotype?

Assign the sex of the human having XO,XXX,XXY and XYY chromosomes.

What is test cross? Give its significance?

What is the product rule?

Define probability.

What is hypophosphatemic rickets?

Define pleiotropy. Give two examples.