Reproduction  Reproduction: making a copy of something  Two Types: Asexual and Sexual

Asexual Reproduction  Asexual Reproduction-the new generation is genetically identical to the parent  Also called a clone  Advantages?  Disadvantages?

Sexual Reproduction  Sexual Reproduction: egg and sperm (gametes) unite so different combinations of genetics result  Advantages?  Disadvantages?

Chromosomes  Except for the gametes, humans have 46 chromosomes (23 pairs) in the nucleus of every cell  Chromosomes are long strands of DNA (genetic code) that are wrapped around proteins called histones  When chromosomes are coiled, they look like a string

Types of Chromosomes  Autosomal  Chromosomes pairs #1-22  Code for almost everything except the sex of the individual  Sex  Chromosome pair #23  Determine sex and some other features  XY is male  XX is female  Is the sex of the offspring determined by the male?

 Homologous Chromosomes : chromosomes that are the same size and shape and code for the same traits. These are the chromosome “pairs”.

Karyotype  Karyotype: a display of all of the chromosomes in a cell.

Heredity  What two factors determine physical features and behavior of an organism?