Download presentation
Presentation is loading. Please wait.
1
Cell Reproduction Mitosis & Meiosis
2
http://biotech-adventure. okstate
3
Cell Cycle
4
Mitosis One type of cell division
Cell process in which the nucleus divides to form two nuclei identical to each other, and identical to the original nucleus, in a series of steps (prophase, metaphase, anaphase, and telophase)
5
Mitosis allows for growth and replaces worn out or damaged cells.
6
Interphase Period of growth & development
Hereditary information (DNA) copied (replicated / duplicated) Cells that do not divide (nerves) are always in interphase
7
http://biotech-adventure. okstate
8
Prophase DNA begins to shorten & thicken Centromeres form
Now called chromatids / chromosomes Centromeres form Nuclear membrane breaks apart Spindle fibers form
9
http://biotech-adventure. okstate
10
Metaphase Chromatids / chromosomes line up
Centromere attaches to spindle fibers
11
http://biotech-adventure. okstate
12
Anaphase Centromeres divide Spindle fibers shorten
Chromatid pairs separate – move to ends of cell Chromatids are now called Each ½ of the pair is now called a chromosome
13
http://biotech-adventure. okstate
14
Telophase Spindle fibers disappear Chromosomes uncoil
Nuclear membrane forms Cell divides (cytokinesis)
15
http://biotech-adventure. okstate
16
Interphase Prophase Metaphase Anaphase Telophase
17
Mitosis Animation
18
Results of Mitosis Division of nucleus
Nuclei are identical to each other Same number & type of chromosomes
19
Asexual Reproduction A type of reproduction - fission, budding, and regeneration - in which a new organism is produced from one parent and has DNA identical to the parent organism.
20
Asexual Reproduction Offspring produced from one organism
Hereditary information is identical Mitosis is one form of asexual reproduction
21
Sexual Reproduction Meiosis
22
Sexual Reproduction A type of reproduction in which two sex cells, usually an egg and a sperm, join to form a zygote, which will develop into a new organism with a unique identity.
23
Sexual reproduction results in a great variety, or diversity, of offspring.
24
Meiosis The nucleus divides twice Meiosis I Meiosis II
26
Interphase DNA is duplicated
27
Prophase I DNA shorten & thicken Forms chromatids / chromosomes
28
http://biotech-adventure. okstate
29
Metaphase I Copied chromatids / chromosomes line up in middle of cell
Centromeres attach to spindle fibers
30
http://biotech-adventure. okstate
31
Anaphase I Chromatid pairs are pulled apart Move to ends of cell
They DO NOT separate Move to ends of cell
32
http://biotech-adventure. okstate
33
Telophase I Cell divides No further replication of hereditary material
34
http://biotech-adventure. okstate
35
There are now two cells. Both cells have full sets of genetic material (chromosomes)
36
Prophase II Similar to mitosis Starts with TWO cells instead of one
Spindle fibers appear
37
http://biotech-adventure. okstate
38
Metaphase II Duplicated chromatid / chromosomes line up in middle of cell Spindle fibers attach to centromeres
39
http://biotech-adventure. okstate
40
Anaphase II Centromere divides
Chromatids separate & move to ends of cell Chromatids are now individual chromosomes
41
http://biotech-adventure. okstate
42
Telophase II Spindle fibers disappear
Nuclear membranes form at each end of cell Cells divide Results in 4 cells Each with ½ the original number of chromosomes
43
http://biotech-adventure. okstate
44
Meiosis Animation
45
In summary: Meiosis Two cells form during meiosis I
In meiosis II, both of these cells form two cells The two divisions of the nucleus result in four sex cells (gametes) Each has one-half the number of chromosomes in its nucleus that was in the original nucleus
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.