AND LAW OF

INHERTANCE,

HUMAN GENOME

PROJECT,

THE GENOMIC ERA

…………………..

BY:- FIROZ QURESHIDEPT. PSYCHIATRIC NURSING

INTRODUCTION

During mid 19th Century The AUGUSTINIAN MONK GREGOR MENDAL observed that certain features pass from parents to their children. A child usually looks like their parents and is due to inheritance of certain characteristics from parents. This Transmission of characteristics from parents to children is known as heredity is gene, which consist of portion of DNAmolecules.

CELL DIVISION

Cell division is a process by which a cell, called the parent cell, divides in to two or more cells, called Daughter Cell. Division is usually a small segment of a lager cell cycle.

Genetic information is passed from parent to all the descendant cell through cell division.

PHASES OF CELL CYCLE

There are two major phases of cell cycle.

MEIOSIS PHASE

MITOSIS PHASES

MEIOSIS PHASE

Meiosis phase consist of two stages, namely as Meiosis I and Meiosis II.

MEIOSIS I

Consist of separating the pairs of homologous chromosome, each made up of two sister chromatids, in two cells.

MEIOSIS PHASE CONT…

MEIOSIS II- The two cell resulting from meiosis I divide during meiosis II, creating 4 haploid daughter cells.

MITOSIS PHASE

It is the final phase of cell cycle in which two daughter cell are produced. There are four different phase of mitosis.

Prophase

Metaphase

Anaphase

Telephase

PROPHASE

The changes occurring in this phase are:

Condensation of chromatin.

Replication of centrome.

METAPHASE

The changes in this phase are:

Gradual breaking of nuclear membrane which later disappears.

Movement of centrosomes and alignment of chromosomes.

ANAPHASE

The changes in this phase are:

Division and movement of chromosomes

Division of cytoplasm

TELOPHASE

During this phase, two identical, individual daughter cell are formed.

GENE MUTATION

Gene mutation is a permanent change in the DNA base sequence that makes up a gene.

The first recorded gene mutation are Ancon Sheep (1791).

CAUSES OF GENE MUTATION

Physical factors:

They are two types –

Temperature- Rise in temperature breaks the hydrogen bonding between the two strands of DNA.

High Energy Radiation- They includes neutrons, Beta rays , Ultraviolet rays etc.

FACTORS

Chemical Factors:

Nitrogen acid, some of drugs are known to cause gene mutation.

TYPES OF GENE MUTATION

1.Germline or Inherited Mutation-

Mutations that are passed from parent to child are called inherited mutation. This type of mutation is present throughout a life in every cell in the body.

TYPES

2. Somatic or Acquired Mutation-

Acquired mutation occur in the DNA of individual cells at some time during a person’s life.

EFFECT OF GENE MUTATION ON HEALTH AND DEVELOPMENT when a mutation alters a protein that

plays a critical role in the body, it can disrupt normal development or cause by mutation in one more genes is called a genetic disorder.

It is important to note that genes themselves do not cause disease. Genetic disorder are caused by mutation that make a gene function improperly.

LAW OF INHERITANCE

Heredity is the transmission of genetic character from parents to the offspring. Gregor Johann Mendel (1866) proposed that inheritance is controlled by paired germinal units now called as genes.

Mendel has given following laws of inheritance :

LAW CONT…………….

1-Law of dominance- In heterozygous individual, a character is represented by two contrasting factor called alleles. Out of the two alleles , only one is able to express its effect in the individual. Its called as dominant allele. The other which does not show its effect in the heterozygous individual is called recessive allele.

LAW CONT………..

2.Law of segregation- The two factors of a characteristic which remain together in an individual do not get mixed up but keep their identity distinct, separate at time of gametogenesis , get randomly distributed to different gametes then get paired again in different offspring as per the principle of probability.

LAW CONT……………..

3.Law of independent assortment-According to this principle , the two factor of each character assort or separate independent of each of the factors of other character at the time of gamete formation and get randomly re –arranged in the offspring.

HUMAN GENOME PROJECT

INTRODUCTION-

The human genome project was an international research effort to determine the sequence of the human genome, and identify the genes that it contains.

The project was co-ordinated by the National institutes of health and the U.S. Department of energy.

MEANING OF HGP

A genome is an organism complete set of DNA, including all of its genes. Each genome contains all of the information needed to build and maintain that organism.

Genes carry the information for making all the protein required by all organisms

These proteins determine, among other things, how the organism looks, how well its body metabolizes food or fight infection.

GOALS OF HGP

Identify

Determine

Store

Improve

Transfer

Address

GENOMIC ERA

The genomic era can be said to have a precise birth date, it was in the midst of the appearance of the series, on April 14, 2003. That was when the international effort known as the human genome project put a close to pregenomic era with its announcement that it had achieved of the project original goal the complete sequencing of the human genome.