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TN 12th Computer Applications மின்னணு தரவு பரிமாற்றம் Sample Question Papers Study Material - QB365 Set A

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TN 12th Computer Applications மின் - வணிக பாதுகாப்பு அமைப்புகள் Sample Question Papers Study Material - QB365 Set A

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TN 12th Computer Applications மின்னணு செலுத்தல் முறைகள் Sample Question Papers Study Material - QB365 Set A

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TN 12th Computer Applications மின் - வணிகம் Sample Question Papers Study Material - QB365 Set A

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12th Standard

TN 12th Computer Applications திறந்த மூல கருத்துருக்கள் Sample Question Papers Study Material - QB365 Set A

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TN 12th Computer Applications வலையமைப்பு வடமிடல் Sample Question Papers Study Material - QB365 Set A

12th Standard Biology English Medium Zoology - Principles of Inheritance and Variation 2 Mark Book Back Question Paper and Answer Key 2022 - 2023

Published on: 26/08/2022

QB365 provides a detailed and simple solution for every Possible Book Back Questions in Class 12 Biology Subject - Zoology - Principles of Inheritance and Variation, English Medium. It will help Students to get more practice questions, Students can Practice these question papers in addition to score best marks.

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Std: 12th Standard - Biology

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Questions:

Generic 2

7 x 2 = 14

Mention the symptoms of Down's syndrome.

Mention the symptoms of Phenylketonuria

What are holandric genes?

What is criss-cross inheritance?

What is Lyonisation?

Distinguish between heterogametic and homogametic sex determination systems

What is haplodiploidy?

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Answers Key:

Generic 2

7 x 2 = 14

Symptoms:
1. Severe mental retardation
2. Defective development of the CNS.
3. Increased separation between the eyes.
4. Flattened nose, ears are malformed
5. Mouth is constantly open and the tongue protrudes.

Symptoms:
1. Severe mental retardation (Phenylpyruvic acid which damages the brain).
2. Light pigmentation (reduction of color) of skin and hair.

The genes present in the differential region of Y chromosome are called Y- linked or holandric genes. The Y linked genes have no corresponding allele on X chromosome. The Y linked genes inherit along with Y chromosome and they are phenotypically express only in the male sex.

It is the transmission of a gene from mother to son or father to daughter.
These patterns of inheritance are called criss-cross inheritance (or) skip generation inheritance in which a character is inherited to the second generation through the carrier of first-generation.
E.g., Wing color in the magpie moth (Abraxus) feather pattern in chickens

The inactivation of an X chromosome one of the two X chromosomes in every cell in some female mammal is randomly inactivated early in embryonic development and named after geneticist Mary Lyon.
The inactive X chromosome is silenced by it being packaged in such a way that it has a transcriptionally inactive structure called heterochromatin found in nucleoplasm of nucleus.

Heterogametic sex determination	Homogametic sex determination
Produces identical gametes (produces one type of gamete)	Produces two different gametes
Two sex chromosomes of the organism are same (XX) (Females)	Two sex chromosomes of the organism are different (XY) (Males)

Haplodiploidy is a sex determination system in which males develop from unfertilized eggs are haploid, and female develops from fertilized egg and is diploid.
It is sometimes called arrhenotoky.
e.g., Honeybees, ants, and wasps.