Cell Division and ReproductionChapter 10

Cell Division

✤ Cells die and are replaced billions of times per day.

✤ Organisms grow because cell division increases the total number of cells.

✤ Cell division is important to single celled organisms as well, it is how they reproduce.

Reproduction

✤ Reproduction is the process where an organism produces others of its same kind.

✤ There are two types of reproduction:

✤ Asexual and Sexual Reproduction

Asexual Reproduction

✤ This is a new organism that is produced from one organism.

✤ This new organism will have genetic material identical to the parent.

✤ How is this done?

Asexual Reproduction

✤ There are 3 types of asexual reproduction:

✤ Budding

✤ Regeneration

✤ Cellular Division

Budding and Regeneration

✤ Budding- The new organism grows from the body of the parent.

✤ Regeneration- These use cell division to reproduce body parts. They may also break into pieces to form new organisms.

Asexual Cell Division

✤ Some organisms can reproduce this way.

✤ Many plants use this type of reproduction.

✤ Sweet potato and strawberries.

Mitosis

✤ Mitosis is the process in which the nucleus of a cell divides to form 2 identical nuclei.

✤ There are 4 steps to mitosis.

✤ Prophase, Metaphase, Anaphase, Telophase (PMAT)

Steps of Mitosis

PROPHASE METAPHASE

ANAPHASE TELOPHASE

Sexual Reproduction

✤ This is another way that organisms can reproduce.

✤ In this situation, there are 2 sex cells. Often called and egg (female) and sperm (male).

✤ When joining it is called fertilization, and the cell formed is called a zygote.

✤ The process of forming sex cells is done through meiosis.

Meiosis

✤ Meiosis produces sex cells. This ensures that offspring have the same number of chromosomes.

✤ In humans, each sex cell has 23 chromosomes. Each parent has 46 chromosomes.

✤ Sex cells are called haploid cells (half the genetic information)

Meiosis

✤ Meiosis has two man parts: Meiosis I and Meiosis II.

✤ Meiosis I- Each cell duplicates just like in Mitosis. (DIPLOID CELLS)

✤ Meiosis II- The two cells formed during MI duplicate to form 4 sex cells. Each have half the number of chromosomes as the original parent cell. (HAPLOID CELLS)

Why is sexual reproduction important?