Cellular Reproduction of Sex Cells
Science V
Assignment Checking
Why is fertilization in human important?
Review
What do ovaries produce? What hormones are produced in the
testes? Why are egg cells and sperm cells
important? Why are ovaries and testes important?
Vocabulary
ASEXUAL REPRODUCTION: involves one parent; daughter cells are identical to the parent cell
SEXUAL REPRODUCTION: involves two parent cells; each parent gives some of its traits (characteristics) to the offspring
Vocabulary
MITOSIS produces two cells with the same diploid (two sets) number of chromosomes
MEIOSIS produces four cells with only one set of chromosomes (called monoploid or haploid); these cells are called gametes:
Motivation
Do you know how sperm cells and egg cells are formed?
Egg and SpermEgg cells are formed in the female's reproductive organ, the ovary. Sperm cells are developed in the male's reproductive organ, the testes. In their first stage, they are called germ cell and look like any other cells in the human body with the same number of chromosomes and genetic information.
In the ovary and the testes, germ cells reproduce many times over by the process of mitosis.
The transformation of an egg cell and sperm cells from their respective germ cells by the process of meiosis.
In the ovary, the germ cell undergoes meiosis I producing one big haploid cell and one small haploid cell.
After meiosis II, three small haploid cells and one big haploid cell are produced.
Concept Formation How do the germ cells divide?
Concept Formation How do the germ cells divide?
Through the process of mitosis.
Concept Formation What happens in the ovary in meiosis
I?
Concept Formation What happens in the ovary in meiosis
I? Meiosis I divides and produce one big
haploid cell and one small haploid cell.
Concept Formation What happens in the ovary in meiosis
II?
Concept Formation What happens in the ovary in meiosis
II? Meiosis II doubles the number of cells
and produce four (3 small and 1 big) haploid gametes. These haploids do
not grow and divide again.
Concept Formation How do germ cells in the testes
divide?
Concept Formation How do germ cells in the testes
divide?A single germ cell divides to form two
daughter cells. These cells grow, and then divide to form a total of four cells.
Application
Compare the cellular reproduction of male with the female.
Application
Evaluation
Illustrate the cellular reproduction of egg cell and sperm cell.
Evaluation
Assignment
What are germ cells?
AssignmentGerm cells are specialized cells which are involved in reproduction. The most well known examples of this type of cell are gametes, the sperm and eggs which come together to create a zygote which can develop into a fetus.