gametogenesis - perry localgametogenesis the production of gametes. sperm cells (male gamete)...
TRANSCRIPT
section6.1.notebook
1
November 14, 2013
You have two types of cells in your body: somatic cells, and germ cells.
Somatic cells are your body cells. They undergo mitosis when they need to divide.
Germ cells are your reproductive cells also referred to as gametes.
male gametes are called sperm cellsfemale gametes are called egg cells.
Sexual reproduction involves the fusion of two gametes that results in offspring that are a genetic mixture of both parents.
section6.1.notebook
2
November 14, 2013
Gametogenesis the production of gametes.
Sperm cells (male gamete)smaller than female gametecontribution to the embryo is DNAmust be able to swim, modifications are made to the cell for this to happen.
Egg cells (female gamete)gives DNA, contributes organelles, molecular building blocks, and other materials for a successful
embryo to develop
section6.1.notebook
3
November 14, 2013
Fertilization the actual fusion of two gametes. Occurs when the sperm fertilizes the egg.
A zygote is formed that will have the number of chromosomes in a diploid cell.
Develops by mitosis into a multicellular organism.
Diploid a cell with 2 copies of each chromosome, (2n) number of chromosomes, body cells are diploid.
one from female parentone from male parent
Haploid gametes that contain only one of each kind of chromosome (n) number of chromosomes.
section6.1.notebook
4
November 14, 2013
Each organism has a specific amount of chromosomes in their cells. The number of chromosomes is not related to the complexity of an organism.
Examples: Adder's Tongue Fern 1260(2n) 630(n)Fruit Fly 8(2n) 4(n)Humans 46(2n) 23(n)
Autosomes chromosomes that contain genes for characteristics not directly related to the sex of an organism.
Chromosome pairs 122 are autosomes
Sex Chromosomes ones that control the development of sexual characteristics.
Very different from one another. X and Y are standardXX indicates female, XY indicates maleChromosome pair 23.
section6.1.notebook
5
November 14, 2013
Human cells have 46 chromosomes.If cells only reproduced through mitosis then when an
egg cell and a sperm cell fuse, the new cell would have 92 chromosomes!
Meiosis is the type of cell division that produces gametes with half the number of chromosomes as a parent's body cells.
Two separate divisions occur (Meiosis I and II)Begins with 1 diploid (2n) cell, and results in 4 haploid
(n) cells.
section6.1.notebook
6
November 14, 2013
Homologous chromosomes two chromosomes (one from mom and one from dad) that have the same length and same general appearance.
contain the same genes in the same order.
section6.1.notebook
7
November 14, 2013
Can you identify Homologous Chromosomes?
The diagram below shows chromosomes 1 with four different genes present. These genes are represented by the letters F, g, h, and J. Possible homologous chromosomes of chromosome 1 are labeled 25. Examine the five chromosomes and the genes they contain to determine which of chromosomes 25 are homologous with chromosome 1.
section6.1.notebook
8
November 14, 2013
1. Could chromosome 2 be homologous with chromosome 1? Explain.
2. Could chromosomes 4 be homologous with chromosome 1? Explain.
3. Could chromsome 4 be homologous with chromosome 1? Explain.
4. Could chromosome 5 be homologous with chromosome 1? Explain
yes, because the genes are in the same location and position
no, because the last gene is not the same
no, because they have completely different genes
yes, same as #1