Principles of Inheritance and Variation BIOLOGY - Principles of Inheritance and Variation

Homozygous and Hetrozygous.

Incomplete dominance.

Explain the following terms with example.
Co-dominance.

What is point mutation? Give one example.

Monohybrid and Dihybrid.

Define and design a test-cross.

Using a Punnett Square, workout the distribution of phenotypic features in the first filial generation after a cross between a homozygous female and a heterozygous male for a single locus.

What is pedigree analysis? Suggest how such an analysis, can be useful.

When a cross in made between tall plant with yellow seeds (TtYy) and tall plant with green seed (Ttyy), what proportions of phenotype in the offspring could be expected to be,

1. Tall and green.
2. Dwarf and green.

Mention the advantages of selecting pea plant for experiment by Mendel.

Who had proposed the chromosomal theory of the inheritance?

Name the type of cross that would help to find the genotype of a pea plant bearing violet flowers.

Name the stage of cell division where segregation of an independent pair of chromosomes occurs.

Name the type of cross that would help to find the genotype of a pea plant bearing violet flowers.

A male honeybee has 16 chromosomes whereas its female has 32 chromosomes. Give one reason.

A nutritionally wild type organism which does not require additional biochemicals is:

Occasionally, a single gene may express more than one effect. The phenomenon is called:

Who discovered nucleosome?

The minimum requirement for mutation is a:

Rarely observed phenotype in population is called as:

For question two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

1. Both assertion and reason are true and reason is the correct explanation of assertion.
2. Both assertion and reason are true but reason is not the correct explanation of assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

Assertion : Y chromosome causes maleness.
Reason: If the number of X chromosome is more than one, femaleness dominates.

For question two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

1. Both assertion and reason are true and reason is the correct explanation of assertion.
2. Both assertion and reason are true but reason is not the correct explanation of assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

Assertion: In some Drosophila, bilateral gynandromorphs are found.
Reason: The gynandromorphs are formed by an irregularity in mitosis at the first cleavage of the zygote.

For question two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

1. Both assertion and reason are true and reason is the correct explanation of assertion.
2. Both assertion and reason are true but reason is not the correct explanation of assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

Assertion : Linked gene show dihybrid ratio of 9 : 3 : 3 : 1.
Reason: Linked gene undergo independent assortment.

For question two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

1. Both assertion and reason are true and reason is the correct explanation of assertion.
2. Both assertion and reason are true but reason is not the correct explanation of assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

Assertion: Complementary genes are non-allelic genes.
Reason: Complementary genes interact to produce a completely new trait.

Directions: In the following questions, the Assertions (A) and Reason(s) (R) have been put forward. Read both the statements carefully and choose the correct alternative from the following:
Assertion: Phenylketonuria is a recessive hereditary disease caused by body's failure to oxidise an amino acid phenylalanine to tryrosine, because of a defective enzyme.
Reason: It results the presence of phenylalanine acid in urine.

1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion.
2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion.
3. If the assertion is true but the reason is false.
4. If both the assertion and reason are false.
5. If the assertion is false but reason is true.

Mention any two autosomal genetic disorders with their symptoms.

Briefly mention the contribution of T.H. Morgan in genetics.

Explain the Law of Dominance using a monohybrid cross.

How is sex determined in human beings?

Two heterozygous parents are crossed. If the two loci are linked what would be the distribution of phenotypic features in F₁ generation for a dibybrid cross?