1. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 7 19 20 21 22 Y X

2. Look at the spread of human chromosomes (Called Karyotype):
List at least three facts that you can observe.
Why do the chromosomes come in pairs?

3. The microscopic image of the chromosomes can be re-arranged,
. So that the chromosomes are paired up by size, shape, and pattern of bands.

4. In humans…
There are 46 chromosomes, or 22 pairs of autosomes, PLUS 2 sex chromosomes: XX or XY.
Boy or girl?

5. Diploid human
Homologous
Sister chromatids

6. Homologous chromosomes:
- Same type of chromosome
- Look identical but carry different information.
Each came from a different parent.
Sister Chromatids:
Duplicate chromosomes that are still connected.

7. 2 sets of chromosomes 1 set of chromosomes
Diploid vs. Haploid cells:
(‘Half’)
2 sets of chromosomes
1 set of chromosomes
“2N”
(human 2N=46)
“N”
(human N=23)
Gametes
(egg&sperm)
(Germ cells)
Body Cells, Zygote

8. Apply: Write the diploid and haploid numbers for the following organisms:
Diploid (zygote, body cells)
Haploid (gametes)
Humans
Fruit fly
Dog
Broccoli
Lizard
Shrimp 46 23 8 4 78 39 18 9 36 18
254
127

10. Which of the following has, on average, larger cells – a sequoia tree, or a daisy plant? An elephant or an ant? Explain your answer.

11. Describe what is happening in the video clip.
What could be the purpose of this process? At least 2 ideas.

12. Altogether, cells divide in order to:
A. Enable growth while cells are kept small.
B. Replace old/damaged cells.
C. For A-sexual Reproduction.

13. When new cells are made, the existing cells divide.
Mitosis: the symmetrical movement of the duplicated chromosomes to the two daughter cells.
Products: Two diploid cells that are identical to the original cell.

14. We will demonstrate mitosis using yarn pieces as chromosomes.
Mitosis 4 to 8 cells
Mitosis is Action (Animal)
Mitosis HeLa Cells
Root Growing
Mitosis - Lily
We will demonstrate mitosis using yarn pieces as chromosomes.

15. Mitosis Animation

16. STEPS of Mitosis: Yarn Simulation
Parts of the kit:
Raise two chromosomes that are:
A. Homologous to one another.
B. Sister Chromatids
C. Choose the correct sheet.
Process:
Follow the process with your yarn pieces. Draw, Label, Describe.

18. * Bats have 72 chromosomes in all of their body cells.
* The first cell of the organism is made by joining egg and sperm.
How many chromosomes in a bat egg or a sperm cell? Explain.
Can cell division by mitosis (duplication of cells) produce egg or sperm? Explain.

19. ? ?
Gametes
HUMANS! 46
Zygote

20. 23 23
Gametes
HUMANS! 46
Zygote

21. ? ?
Gametes
BATS! 72
Zygote

22. 36 36
Gametes
BATS! 72
Zygote

23. Mitosis: 1 Diploid to 2 Diploids:
DNA replication 2N 4N 2N 2N
Tetraploid
Meiosis: 1 Diploid to 4 Haploids:
DNA replication 1N 1N 4N 2N 1N 1N

24. Purpose: Make more identical diploid cells. Mitosis: Mitosis animation
Meiosis:
a. Reduce chromosome number by half
b. Create genetic diversity
Meiosis Animation animation

25. Yarn Kit: Meiosis (finally..)
Using the four colors Show the split-split process.
What do you get?
Drawing of mitosis and meiosis