Question

Describe the structure, Identify the different mechanisms of mutation and discuss the effect of these mutations on survival. components, and function of DNA/RNA. . Identify importance of understanding teratogenic effects. . Differentiate between genotype and phenotype. Give examples of each. Identify major chromosomal abnormalities/aberrations. Differentiate between autosomal dominant, autosomal recessive, and X linked recessive inheritance modes. . Be able to interpret info provided for determining probability for these inheritance modes Describe sex-linked traits and give an example. .

Answer 1

Q. No. 1. Answer :

DNA : structur: Deoxyriboneuclic acid is a molecule , it is having two chains those are coil around each other to form like double helix, and these are carries genetic instructions used in the growth and development and functioning of all living organism.

Components of DNA :

Those are :

1. Phasphates

2. Deoxyribose it is a sugar and

3. Nitrogenous bases are 4 those are

* adenine

* guanine

* cytocine

* thymine

These are the components of DNA.

functions of dna :

* it is acts like a storage of all genetic information for longer periods.

* it will give instructions to synthesis of proteins.

* there is a susceptibility to mutations due to any single gene change may cause.

* it pass the genetic information during in the cell division by replication.

These are the main functions of DNA.

Q. No. 3. Answer :

Teratogenic effects : means deleterious effects on the development of embryo.

The knowing is very important because, to prevent consequences which are raising if the future.

If there is a severe the parents can under go medical termination of pregnancy .

By knowing this we can provide the quality of births to babies.

Q. NO. 2. ANSWER :

Mutation is a permanent alteration in the DNA sequence which makes up a gene .

Mutations like substitution, deletions and insertions.

Substitutions are single point mutations like Glu -> val which means glutamic acid instead code for the amino acid valin.

Ex. Sickle cell disease.

Deletions in these part of a chromosome or sequence of DNA missing during replication.

Ex : cri- du- chart syndrome in children due to missing of 5 th chromosome.

Insertions : that means one or more nucleotide bases pairs entering in to DNA sequence.

Ex: Cystic fibrosis one of the example for this.

So the gene mutations are affect health like this above examples.

So that the survival rate may be decreases.

Q. No. 8. Answer :

Sex linked traits : these are sex linked genes , particularly these are important categories of genetic linkage like X and Y chromosomes. These are not only carry the genes but also determine the male and female traits, so genes carried by either sex but chromosomes are called to be a sex linked.

Sex linked traits are associated with genes found on sex chromosomes, in human beings are having X and Y chromosomes, x linked traits are more common than y linked traits.

Example : Red green color blind ness. This is an example for sex linked traits, here carries X chromosome more.