mitosis cell division review
Download
Skip this Video
Download Presentation
Mitosis/Cell Division Review

Loading in 2 Seconds...

play fullscreen
1 / 30

Mitosis/Cell Division Review - PowerPoint PPT Presentation


  • 65 Views
  • Uploaded on

Mitosis/Cell Division Review. A. B. C. D. E. Meiosis . Produces gametes or sex cells (sperm and egg cells) Occurs ONLY in the reproductive organs. Products of Meiosis = 4 new cells. AND. Divides the chromosome number in half. For Example: . Parent Cell. 4 daughter cells.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Mitosis/Cell Division Review' - harva


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide2

A

B

C

D

E

slide3

Meiosis

  • Produces gametes or sex cells (sperm and egg cells)
  • Occurs ONLY in the reproductive organs
slide4

Products of Meiosis = 4 new cells

AND

Divides the chromosome

number in half

slide5

For Example:

Parent Cell

4 daughter cells

slide6

2 Sets of Divisions

1st division is exactly like mitosis

except sister chromatids stay together

slide8

Before the 1st division takes

place DNA MUST replicate

slide9

Prophase I

  • Chromosomes condense
  • Homologous chromosomes pair together
  • Crossing over occurs
slide12

Metaphase I

  • Homologous pairs are moved to the equator (middle) of the cell
slide13

Anaphase I

  • Homologous pairs separate
  • Chromatids remain together
  • Genetic material has been recombined
slide14

Telophase I

  • Chromosomes gather at poles
  • Cytoplasm divides
slide15

2nd DIVISION BEGINS

DNA replication

DOES NOT

occur

slide16

Prophase 2

  • New spindles form around chromosomes
  • Crossing over – does not occur!
slide17

Metaphase 2

  • Chromosomes align along with equator (middle) of the cells
slide18

Anaphase 2

  • Sister chromatids (now called chromosomes) divide and move to opposite poles
slide19

Telophase 2

  • Chromosomes gather at the poles
  • Nuclear envelope forms and cytoplasm divides

4 new daughter cells, each genetically DIFFERENT, are formed and are all haploid

slide21

Sexual Reproduction

  • Haploid cells join to make diploid cells
  • Increase in genetic variation
  • Leads to change or evolution
slide22

Females: meiosis occurs before birth

Each month, one egg is matured

and released for possible fertilization

Males: meiosis begins at puberty

and continues until death

slide23

Asexual Reproduction

  • Single parents pass genes to offspring
      • Clones
      • Prokaryotes, yeast, hydra
      • Faster to produce offspring, but no genetic variation
slide24

GENETIC VARIATION

  • The chromosome a gamete will receive depends on the way it lines up at the equator

Independent

assortment

slide25

The Importance

  • Lead to the evolution of a species
  • Increase survival
slide26

CANCER

  • Cells have checkpoints to determine if they are healthy enough to divide
  • If those checkpoints are faulty, cells can divide and grow uncontrollable – can form a tumor and lead to cancer
slide28

What’s the problem

with more cells?

1.) Steal nutrients from healthy cells which eventually die

slide30

Causes of Cancer

  • Exposure to chemicals or toxins
  • Radiation
  • Viruses
  • Your Own Genetics
ad