1. Cell Growth and Reproduction

2. Cell Size Limitations
How does a cell receive materials and expel its wastes?
Through the plasma membrane
This means that no part of the cell can be too far away
Mitochondria of a cell 20 cm wide would have to wait months

3. Surface Area to Volume Ratio
The more volume = more cytoplasm
= more energy requirements
Volume increases much greater than surface area
If a cell a cell were to double; it would require 8X as much nutrients

5. Cell Reproduction Recall cell theory One cell becomes two
Chromosomes – structures which contain DNA and are carriers of genetic material that is copied and passed from generation to generation

6. Cell Reproduction cont…
Most of time as chromatin
Chromatin – long strands of DNA wrapped around proteins
Condenses before cell division
Cell division follows a pattern or cycle

7. Chromosomes

8. The Cell Cycle Events that occur in the life of a cell
Includes 3 major stages:
Interphase
Mitosis
Cytokinesis

10. Interphase Most of the cell cycle is in what stage? 3 parts
G1- rapid growth and metabolic activity
S – DNA synthesis and replication
G2 – Cell prepares for division

11. Mitosis Cells undergo division when they get to a certain size
Continuous process
Stages are named for ease of identification

12. Steps of Mitosis
Prophase
Metaphase
Anaphase
Telophase
Cytokinesis

13. Prophase Chromatin condenses into chromosomes
Two halves called sister chromatids are held together by contromere
Nucleus disentegrates
Centrioles go to poles
Spindle forms

14. Prophase

15. Metaphase Chromosomes pulled by spindle fibers at the centromeres
Sister chromatids lined up in the middle
Single file

16. Metaphase

17. Anaphase Centromeres split
Sister chromatids pulled apart by spindle fibers
Pulled to opposite sides

18. Anaphase

19. Telophase Chromatids reach opposite poles Chromosomes unwind
Spindle breaks down
Nuclear membrane and nucleolus reappear

20. Telophase

21. Cytokinesis Dividing the cytoplasm between the two new daughter cells
Cleavage furrow in animal cells
Cell plate in plant cells

22. Cytokinesis in Animals

23. Cytokinesis in Plants

25. Mitosis in Onion Cell

26. Mitosis in Whitefish

27. In mitosis, the two double copies of the DNA attached to the spindle fibers are known as __________.
a.  centromeres  
b.  chromatids  
c.  centrioles  
d.  nucleoli

32. During which phase do most cells spend the most time?
a.  prophase  
b.  metaphase  
c.  anaphase  
d.  interphase 

33. If a cell has 20 chromosomes, how many chromosomes will be present in the daughter cells?

34. List the stages of the Cell Cycle in order

35. Name one stage of Interphase