1. ________________ Taking another look at DNA #1

2. DNA… A Quick Review #2

3. What are chromosomes? Chromosomes are ________________ ________________. #3

4. Structure of Chromosomes Sometimes you may see chromosomes in ________. #4

5. Chromosomes come in ________________________ The other matching half comes from the ____________. Half the chromosomes come from the ____________. #5

6. What are genes? #6 Gene for eye color proteins Gene for hair color proteins Genes are _______________ ________________________

7. Different organisms have different ___________________. Fruit fly DNA Human DNA #7 8 chromosomes (__________) 46 chromosomes (__________)

8. All organisms have a certain number of chromosomes in their _____________ cells called the diploid number. __________ (2n)= _____ set of chromosomes (DNA) #8 OrganismDiploid Number Human46 (23 pairs) Corn20 (10 pairs) Dog78 (39 pairs) Chicken78 (39 pairs) Crayfish200 (100 pairs)

9. All organisms only have half the number of chromosomes in their _________________ called the haploid chromosome number. __________ (1n)= _____ set of chromosomes (DNA) #9 OrganismDiploid NumberHaploid Number Human4623 Corn2010 Dog7839 Chicken7839 Crayfish200

10. Imagine a diploid human sperm and egg cell coming together… 46 Sperm (male sex cell) from Dad Baby’s Body Cell 46 Egg (female sex cell) from Mom #10

11. Now, imagine a haploid sperm and egg cell coming together… 23 Sperm (male gamete) from Dad Baby’s Body Cell 23 Egg (female gamete) from Mom #11

12. Keep these numbers in mind: Humans have ___ chromosomes, AKA ___ ______________ _____________. #12