Presentation is loading. Please wait.

Presentation is loading. Please wait.

In meiosis, the nucleus divides to form 4 daughter nuclei. Meiosis allows for differences in inherited characteristics.

Similar presentations


Presentation on theme: "In meiosis, the nucleus divides to form 4 daughter nuclei. Meiosis allows for differences in inherited characteristics."— Presentation transcript:

1 In meiosis, the nucleus divides to form 4 daughter nuclei. Meiosis allows for differences in inherited characteristics.

2 Interphase similar to mitosis. chromosomes are replicated  chromatids subsequent phases differ

3 Prophase I

4 Members of homologous pair do not have identical DNA One from each parent

5

6 Crossing over occurs early in Prophase I genetic recombination an average of 1-3 “crossovers” per pair

7

8 Metaphase I Pairs are not arranged maternal vs. paternal

9 independent assortment

10 Anaphase I In humans, there are roughly 8 million possible combinations per gamete. When gametes fuse, that’s about 64 trillion combinations.

11 Meiosis II

12

13

14

15

16 Cancer Neoplasms (tumors) benign or malignant Malignancy (cancer) fast growing not encapsulated can metastasize

17 Loss of Cell Cycle Control

18 Growth factors (and their receptors) Mechanisms (11.18-21)

19 Oncogenes 1. may code for growth factors or their receptors HER-2, ras called proto-oncogenes when they function normally

20 Loss of “Brakes”

21 Tumor suppressor genes p53

22

23

24 Carcinogens chemicals radiation viruses are mutagens

25 Viruses and Cancer Human Papilloma Virus (HPV) Hepatitis Herpes

26

27 Fig. 06.

28


Download ppt "In meiosis, the nucleus divides to form 4 daughter nuclei. Meiosis allows for differences in inherited characteristics."

Similar presentations


Ads by Google