________________

Taking another look at DNA

#1

DNA… A Quick Review

#2

What are chromosomes?

Chromosomes are ________________________________.

#3

Structure of Chromosomes

Sometimes you may see chromosomes in ________. #

4

Chromosomes come in ________________________

The other matching half comes from the ____________.

Half the chromosomes come from the ____________. #

5

What are genes?

#6

Gene for eye color proteins

Gene for hair color proteins

Genes are _______________________________________________________________________________________

Different organisms have different ___________________.

Fruit fly DNA

Human DNA

#7

8 chromosomes (__________)46 chromosomes (__________)

All organisms have a certain number of chromosomes in their _____________ cells called the diploid number.

__________ (2n)= _____ set of chromosomes (DNA)

#8

Organism Diploid Number

Human 46 (23 pairs)

Corn 20 (10 pairs)

Dog 78 (39 pairs)

Chicken 78 (39 pairs)

Crayfish 200 (100 pairs)

All organisms only have half the number of chromosomes in their _________________ called the haploid chromosome number.

__________ (1n)= _____ set of chromosomes (DNA)

#9

Organism Diploid Number Haploid Number

Human 46 23

Corn 20 10

Dog 78 39

Chicken 78 39

Crayfish 200 200

Imagine a diploid human sperm and egg cell coming together…

46 Sperm (male sex cell) from Dad

Baby’s Body Cell

46Egg (female sex cell) from Mom

#10

Now, imagine a haploid sperm and egg cell coming together…

23 Sperm (male gamete) from Dad

Baby’s Body Cell

23Egg (female gamete) from Mom

#11

Keep these numbers in mind:

Humans have ___ chromosomes, AKA ___ ___________________________.

#12