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

Question # 1

What is contribution of Carl Correns in genetics?

Ans 1: Carl Correns discovered the phenomenon of incomplete dominance.
He crossed red flowered 4 O clock plant with while flowered 4 O clock plant.In f₁pink flowers were produced instead of red color was dominant.He again crossed pink flowers from F_1,in F₂red,pink white flowers obtained with ratio 1:2:1 respectively.

Question # 2

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 # 3

Define crossing over.Give its importance.

Ans 1: Mendel devised a cross called test cross,which is used to test the genotype of an individual showing a dominant phenotype.It is a mating in which an individual showing a dominant phenotype is crossed with an individual showing its recessive phenotype.significance of test cross is it is used to check the homozygosity & heterozygosity of the dominant parent.

Question # 4

What is nullo gametes?

Ans 1: A gamete without sex chromosomes is called nullo gamete.For Example Grasshopper male produce 50% nullo gametes and 50% with sex chromosomes.

Question # 5

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 # 6

What is haemophillia?Give its type.

Ans 1: Haemophilia is rare x-linked recessive trait.Haemophilic's blood does not clot properly after an injury,because it has either a reduction or malfunction or complete absence of blood clotting factor.
It types are Haemophilia A,haemophilia B and haemophila C.

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 Bombay Phenotype?

Ans 1: When in an individuals RBCs lack A and B antigens although the do not contain I^aand I^bgenes.They are phenotypically like O blood group but are not genotypically like O.Their phenotype is called Bombay phenotype.

Question # 9

What is hypophosphatemic rickets?

Ans 1: It is an X linked dominant trait.It is rare hereditary disease.it does not result from vitamin D deficiency but its cause is a genetic communication failure at molecular level.The genes encoding bone proteins never receive vitamin D message to function.

Question # 10

Define recombination frequency.Give an example.

Ans 1: It is the proportion of recombinant type between two gene pairs as compared to sum of all combinations.

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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

What is contribution of Carl Correns in genetics?

Differentiate between multiple alleles and polygenes..

Define crossing over.Give its importance.

What is nullo gametes?

Explain genic system for determination of sex.

What is haemophillia?Give its type.

Explain testicular feminization syndrome.

What is Bombay Phenotype?

What is hypophosphatemic rickets?

Define recombination frequency.Give an example.

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

What is contribution of Carl Correns in genetics?

Differentiate between multiple alleles and polygenes..

Define crossing over.Give its importance.

What is nullo gametes?

Explain genic system for determination of sex.

What is haemophillia?Give its type.

Explain testicular feminization syndrome.

What is Bombay Phenotype?

What is hypophosphatemic rickets?

Define recombination frequency.Give an example.

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

Define incomplete dominance,Give example

Define linkage and give its one disadvantage.

Why is blood group AB called as universal recipient?

Differentiate between population & gene pool.

Two Normal parents have an albino child.What is the probability that their next child will also be an albino?

Define probability.

Explain gene and allele.

What are jumping genes?

In bird's the female is heterogametic. How?

What is Bombay Phenotype?

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

Define polygenic Inheritance.Give example.

Explain gene and allele.

What is the product rule?

How does ABO incompatibility protect the developing baby against Rh-

In bird's the female is heterogametic. How?

Differentiate between gene and allele.

Two Normal parents have an albino child.What is the probability that their next child will also be an albino?

How sex is determined in yeast?

Define linkage and give its one disadvantage.

What are sex limited traits?Give an example.

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

What is nullo gametes?

What are jumping genes?

How sex is determined in plants?

Differentiate between multiple alleles and polygenes..

What is Pleiotropy? Give one example.

Define linkage and give its one disadvantage.

Differentiate between population & gene pool.

Differentiate between multifactorial and polygenic traits.

Define probability.

What is beanbag genetics? Explain.

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

What is nullo gametes?

Differentiate between multiple alleles and polygenes..

What is Bombay Phenotype?

Two Normal parents have an albino child.What is the probability that their next child will also be an albino?

What is tetrad?

Define incomplete dominance,Give example

What is law of segregation?

Why is blood group AB called as universal recipient?