Mitosis and Meiosis

 

Mitosis and Meiosis

Cells divided and reproduce in two ways --- mitosis and meiosis,

Mitosis is a process of cell division that results in two genetically identical daughter cells developing from a single parent cells.

Meiosis, on the other hand, is the division of a germ cell involving two fissions of the nucleus and giving rise to four gametes, or sex cells, each possessing half the number of chromosomes of the original cell.

Comparison chart meiosis and mitosis

                                                Meiosis                                   Mitosis

Definition	Types of cellular reproduction chromosomes are reproduced by half through the separation of homologous chromosomes, producing two haploid cells.	Process of asexual reproduction in which the cell divides in to producing a replica, with an equal number of chromosomes in each resulting diploid celll
Types of reproduction	Sexual	A sexual
Occurs in	Human, animal, plants.	All organism.
over	Can occur	Cannot occur
Chromosomes number	Reduced by half	Remains the same
steps	(meiosis I ) Prophase I Metaphase I, Anaphase I Telophase I, (Meiosis 2) Prophase II, Metaphase II Anaphase II, TelophaseII	Prophase,Metaphase, Anaphase,Telophase
creates	Sex cells only; female egg cells or male sperm cells.	Make everything other than sex cells.
Function	Genetics diversity through sexual reproduction	Cellular reproduction and general growth and repair of the body

 

How Genetic Material Passes from Parents to offspring

The genetic information passed from parent to offspring is contained in genes carried by chromosomes in the nucleus .sexual reproduction produces offspring that resemble their parents, but are not identical to them.

Genetic information

Offspring resemble their parents because they contain genetic information passed on to them by their parents.

Chromosomes and Genes

Chromosomes, found in the cell nucleus, contain many genes. A gene is a section of DNA, which carries coding for a particular protein. Different gene control the development of different characteristics of an organism. Many genes are needed to carry all the genetic information for a whole organism

Nucleus, chromosome, and gene

Genetic factors

The individual of a species may look similar but they are not usually identical, these differences are called variation.

Inherited variation

Variation due to genetic causes is inherited variation. For example, children usually look a little like their father and a little like their mother, but they will not be identical to either of their parents. This is because they get half of their inherited features from each parent. Here are some example of inherited variation .

1.                                        Eye color

2.                                         Hair color

3.                                         Skin color

Environmental variation

Some variation within a species is inherited, and some variation is due to the environment, some variation is due to a combination of both characteristics of animal and plant species can be affected by environment factors like

1.     Climate

2.     Diet

3.     Culture

4.     Lifestyle, for example, one who eats too much will becomes heavier.

Combined Genetic and Environmental Factors

Some features vary because of a combination of genetic causes and environment causes. For example, identical twins have exactly the same genetic information from their parents. But due to nutrition and life style one may appear fit while other may becomes bulky.