Question

• Discuss factors that lead to genetic variations in a population by using the Hardy-Weinberg law that describes allele frequencies in a population.
• Explain how animal behaviors, including human behaviors, are governed by genetic inheritance.
• Explain how the laboratory mouse has become a valuable model organism for the study of development and genetics.
• What other animal models are used?
• What contribution(s) has research using Caenorhabditis elegans and Drosophila melanogaster made in the study of animal behavior and population genetics?
• Elaborate on the future of human disease diagnosis using the data from the Human Genome Project.
• Provide sufficient examples to make the speech relevant to high school students.

Answer 1

According to Hardy-Weinberg law allele frequencies in a population remains constant.

1.The main factors (five factors) which cause genetic variation in a populations (affect Hardy-Weinberg law) are-  

i. Muataion- sudden changes in genetic material which leads to variation

ii- Genetic recombination- this is due to crossing-over during (in pachytene substage of prophase-I of Meiosis-I)gamete formation

iii-Gene flow or Gene migration- it is the migration of allleles from one population to others,lead to changes in gene frequencies.

iv-Genetic drift- similar to gene flow but occur by chance

v-Natural selection- it is the survival of fittest due to better heritable variation.

2- the behaviour or expression of phenotypic traits regulated by genes.

for example if we see in kangaroo rat there is adaptaion to survive in extreme drought condtions

altitude sickness is another axample in human

although individualy genes are not alone regulate all traits but they requires such microenvironment for expression

that is-: H(heridity)* E(environment) = P(product)

3-the main reasons are-

i-mouse have many similar features such as genetic homology (much chromosomal similarity) as to humans.

ii- easy to handle and breed

iii- less economic

iv-short life span

v.easy alternation to genetic design

vi-complete sequencing of genome

the others animals models are - Drosophila (also called jackpot of genetics ) roundworm , monkey etc

4- Reaserchers use fruitfly and C.elegans due to follwing reasons;

C.elegans-

i- easy to mutate and study of human diseases

ii-short life span

iii- simple anatomy and morphology

iv-RNAi has been done

v-eaisy to handle

Drosophila-

i-- less number of chromosome

ii-- produce large number of progeny after breeding

iii- short life span

iv- eaisy to grow in nutrient media

v- similar sex chromosome as human

vi- morphological differences between male(small) and female(large)

5-some common aspects of HGP in human disease diagnosis are-

i-to identify the genes which cause heart , endocrinal and neurological disorder

ii- gene based drug designing

iii-gene based identity of individuals

iv-working patterns of same genes in different cells or tissues

v-interactions of genes products(proteins)

vi- activation of c-onc /cancer causing genes(oncogenes)

vii-to identify the types of transcript(m-RNA) form in different tissues