Back toBasics

Enough fooling around. We get serious today. It’s time for GENETICS

GENETICS - The study of how TRAITS are passed from PARENTS to OFFSPRING

• Offspring usually show at least SOME traits of the parents

• EVERYTHING we do in this chapter happens in CELLS.

• Body Cell (somatic) • Sex CEll (gamete)

• Makes up tissues and organs • Makes Sperm or Egg

• Chromosomes in PAIRS • Chromosomes in SINGLES

• The number of chromosomes in a cell really matters because ALL living things have a very specific CHROMOSOME NUMBER.

For example . . .

• But that’s just us. Different species have different CHROMOSOME NUMBERS. Turn the page and see if you can match the animal to the number of chromosomes in its body cells . . .

26

38

78

36

48

34

Fascinating but does anyone know which animal has the MOST chromosomes in its cells?

254

How about the animal with the LEAST chromosomes in its cells?

2

But remember ALL living things have CELLS and ALL cells have CHROMOSOMES

768

4

• No matter which organism you are looking at, All of their chromosomes have GENES

GENE - A specific section of a chromosome that DETERMINES a specific trait

SEX CELL (gamete)

BODY CELL (somatic)

Now let’s build on this Chromosomes having Genes stuff . . .

Mom’s Egg Dad’s Sperm

• The sperm will fertilize the egg, and you will create a ZYGOTE

But what will this child look like?

To Be Continued . . .