6.1 PPT

There are two main types of cells in the body: body cells (somatic cells) and gametes.
Body cells are diploid (2n) containing two sets of chromosomes, while gametes are haploid (n) with only one set.

Somatic cell: Body cells that comprise most of the body tissues and organs.
Gamete: Sex cells, either ova (eggs) in females or spermatozoa in males, with DNA that can be passed to offspring.
Homologous chromosome: Pairs of chromosomes that are similar in structure and gene content.
Autosome: Non-sex chromosomes, all paired chromosomes except for the sex chromosomes.
Sex chromosome: Chromosomes (X and Y) that determine the sex of an organism.
Sexual reproduction: The process by which offspring are produced through the combination of genetic material from two parents.
Fertilization: The fusion of egg and sperm that restores the diploid chromosome number.
Diploid: Cells possessing two homologous sets of chromosomes (2n).
Haploid: Cells possessing one set of chromosomes (n).
Meiosis: A specialized form of cell division that reduces the chromosome number from diploid to haploid.

Body cells make up tissues like the spleen and kidneys.
Germ cells, located in reproductive organs (ovaries and testes), develop into gametes which can pass genetic information to offspring.
Each human body cell contains 23 pairs of chromosomes. Rows 1-22 are autosomes and the 23rd pair consists of X and Y sex chromosomes determining gender.
In human females, the karyotype is XX, while in males, it is XY.

A karyotype is an organized profile of an individual's chromosomes.
It helps identify chromosomal abnormalities associated with genetic disorders. For example, Turner's Syndrome (XO) and Klinefelter Syndrome (XXY) can affect health and development.

Mitosis is the process of nuclear division that results in two diploid daughter cells genetically identical to the parent cell, occurring throughout an organism's life.
Meiosis involves two rounds of division, resulting in four genetically unique haploid gametes, reducing the chromosome number necessary for sexual reproduction.

In animals, it is essential to maintain the chromosome number across generations to ensure normal physiological function.
The fusion of haploid gametes during fertilization restores the diploid state, combining genetic material from both parents for the offspring to inherit.

Somatic Cells: Diploid, do not pass on genetic material to offspring.
Gametes: Haploid, involved in sexual reproduction, passed on to the next generation.
- Autosomes: Non-sex chromosomes related to bodily traits.
- Sex Chromosomes: X and Y chromosomes determining sexual characteristics.

Meiosis consists of two main phases: the reduction of chromosome numbers from diploid cells to haploid gametes and the subsequent genetic diversity produced through crossing over and independent assortment.
It is vital for the production of sperm and egg cells that maintain genetic integrity through generations.