Heredity And Evolution
Very Short Answer Type Questions
Q.1. What are the different ways in which individuals with a particular trait may increase in population?
Ans. (1) By natural selection the individuals with a particular trait may increase in population.
(2) The sudden hazard in population may increase the particular traits.

Q.2. What factors could lead to the rise of new species ?
Ans. (i) Natural selection.
(ii) The low occurrence of levels of gene flow.
(iii) Such type of sepration between two sub population that their members can not execute mutual reproduction.
(iv) The change in D.N.A.

Short Answer Type Questions
Q.3. What is chromosome ? Draw labbelled diagram of Eukaryotic chromosome and also write two functions.
Ans. Chromosome: A thread like structure of nucleic acid and protein found in nucleus of most living cell. Carrying genetic information in the form of genes.
Two functions of chromosome: (i) They play an important role in heredity. They are responsible to protein synthesis in activity.
(ii) New cells are produced by the replication of chromosome.
Structure of Eukaryotic chromosome.

Q.2. What is Dihybird cross? Explain with example .
Ans.  Dihybrid cross: A cross which involves two characters of each parent is called Dihybrid cross. 
Example: On hybridizing plants of round and yellow seed with plants of wrinkled and green seed, plants of round and yellow seed are obtained in the first generation.
Round yellow seed (Hybrid)
RrYy


Q.3. Why Mendel selected pea plant for his experiment ? Write any five reasons.
Ans. Due to following reasons Mendel slected pea plant for his experiments. 
(i) pea plant can be grown easily everywhere
(ii) it is annual plant of small life cycle.
(iii) it is bisexual and is self pollinated.
(iv) it has many contrasing characters.

Long Answer Type Questions
Q.1. What is Genetics ? Explain Mendel's Law of Dominance.
Ans. Transfer of characters in being from one generation to another generation is called heredity and its study is called Genetics.
Mendel's law of dominance : According to this when a pair  having different alleles is crossed only dominanat character will appear in first generation.
Example : Mendel crossed pure tall plant (TT) with dwarf plant (tt). He found all the plants tall in first generation.