1. Centromere, chromatid, & DNA
Bell Ringer 4.18
What two things can you tell about an organism by it’s karyotype?
Label the following parts of the chromosome:
Centromere, chromatid, & DNA

2. Asexual Reproduction

4. Asexual Reproduction Uses genetic information from only ONE source
NO gametes
Offspring (daughter cells) are exactly like the parent = NO variation

5. Advantages: Disadvantages:
When an organism is perfectly adapted for its environment and no change is needed
Able to reproduce rapidly
Disadvantages:
When an environment is changing, the organism cannot adapt to change as quickly (because there is no variation)

6. Types of Asexual Reproduction
1. Binary Fission
Usually prokaryotes (bacteria)
Cell splits into two parts
Each part receives one copy of the genetic info
Each new cell is identical to the parent cell

8. 2. Budding Yeast and hydra Little buds sprout from parent
Unequal cell division

9. 3. Mitosis Some unicellular organisms use mitosis for reproduction
Multicellular, eukaryotic organisms use mitosis to replace cells lost to injury and to make new cells for growth

10. For multicellular organisms, mitosis is part of
the cell cycle

11. Interphase S: synthesis of DNA
Period of time when a cell is not in mitosis, includes three parts:
S: synthesis of DNA
G2: before mitosis, period of rapid cell growth, more cytoplasm and organelles
G1: before synthesis, major period of cell growth and production of more organelles

12. Mitosis

13. P – Prophase Prepare Nucleolus and nuclear membrane fade
Chromatin in nucleus condenses (coils up) to become chromosomes
Nucleolus and nuclear membrane fade
Centriole move to opposite sides of the cell

14. M - Metaphase Meet/Middle
Centrioles arrive at opposite poles and chromosomes line up in the middle
Spindle fibers guide chromosomes to opposite ends of the cell

15. A - Anaphase
Apart
Connections between the copied chromosomes (centromere) breaks and each copy moves to opposite side of cell

16. T - Telophase Tear in Two
Nuclear membrane and nucleolus reform, chromosomes uncoil to become chromatin

18. Cytokinesis
Occurs after mitosis, stage in the cell cycle during which the cytoplasm splits into two separate cells.

19. Put the following pictures in order
Put the following pictures in order. Identify INTERPHASE and the stages of MITOSIS.

20. Cancer
Abnormal cell cycle, caused by smoking, radiation, viral infection, p53 gene, BRCA1 gene, etc.

21. TOTD What is the end result of mitosis?
Why does each cell undergo interphase?

23. Agenda for Today 4.18… 3 People Hands on Person Drawer
Twizzler Lab
Remainder of Class
3 People
Hands on Person
Drawer
Writer/Question Asker
Use Twizzlers as chromatids and marsh mellows as centromeres!
Sketch & label each phase on color paper
Answer questions on front of packet
Put EVERYTHING back where you found it!
Staple packet, names, & turn in!
Finish Karyotype Lab (Friday)
Unit Guide
Due Friday! (22nd)
Google Classroom Assignment
Missing work

24. TOTD
Why does each cell undergo interphase before mitosis begins?