Reproduction class 12th /Importance of reproduction and basic features of reproduction .NEET/BIOLOGY CLASS 12th CBSE/NCERT 2024_2025 Important topics.

Reproduction: It is a biological process in which an organism produces number of individuals or offsprings of  similar type.

IMPORTANCE OF REPRODUCTION:

1) Continvity of species means group of individuals which are similar in morphology (external features) functions, behavior but they can reproduce sucessfully in natural condition.

2) It maintaines chromosome number.

3) It helps in replacement of organisms.

BASIC FEATURES OF REPRODUCTION:

Before reproduction these features are important.

1) Replication of DNA molecule means forming two or duplicate DNA copies.

2)Formation of RNA molecule, proteins, cells, cell organelles and other biochemicals.

3) Cell division [Mitosis_asexual/Meiosis_sexual].

4) It helps in formation of separate reproductive units (Male/Female).

5) Formation of offsprings is due to combination of reproductive units.

CELL DIVISION:

It is the process by which a parent cell divides into two or more daughter cells .On the basis of cell division are two types of cells .

1.Somatic cells.

2.Germinal cells.

1.SOMATIC CELLS: These are those types of cells which shows only mitotic division.These cells are sort of reproduction i.e, asexual type of reproduction.

2.GERMINAL CELLS: These are those type of cells which shows only meiotic division.The outer lining of testis and ovary are made up of germinal cells.

It has two phase:

1.Interphase.

2.Gophase.

1.INTERPHASE: It is the interval (time) between two successive cell division.

This interval completes into three phase:

1.G1phase: It increases size of the cell.

2.Sphase: Synthesis phase.

3.G2phase Growth 2phase.

Q1. How many types of organs are present in our body?

Ans. 69.