Meosis
MEIOSIS
We study Gametes through a Karyotype
Each pair is called a homologous pair
Diploid= 23 pairs of chromosomes and 46 total chromosomes (2n)
Haploid= 23 individual pairs
Mitosis- makes body cells, or asexual reproduction like cloning
Meiosis- makes sex cells
Crossing Over- Occurs in Prohpase I
- each group of 4 chromatids are called a tetrad.
Individual chromatids may wrap around eachother and pieces may break off and reattach to other chromatids. Genes on chromosomes may change places.
Causes recombiant chromosomes= get new arrangements of genes
This creates variation in offspring.
Look at pictures
Independent assortment- random separation of the homologous chromosomes. This results in genetic variation.
Crossing Over- Portions of chromatids may break off and attach to other chromatids.
Random Fertilization- Not knowing which egg the sperm with fertilize.
STEM CELLS
A stem cell is a cell whose job in the body isn’t determined yet.
Differentiate- gradually change into the destined cell type
Protein Products cause the stem cell to differentiate.
Skin- as they differentiate they move closer to the surface
Bone- they are construction workers
Nerve- these cells are made before birth
Skeletal Muscle Cell- cells made by myoblasts
Red blood cell- made by bone marrow
TOTIPOTENT STEM CELLS- (totipotent)- total power, cell that can become any cell.
Zygote- fertilized egg
Morula- solid ball of 16 cells
1-4 days for cell division
1-16 number of cells
PLURIPOTENT STEM CELLS- (pluripotent)- cell that can become several cell types
Blastula/Blastocyst- Hollow ball of cells with inner cell mass
4-14 days for cell division
100’s of cells
Embryonic stem cell- cells from the inner cell mass growing in a culture
Made by destroying blastula and removing inner cell mass.
Most debatable and easy to grow
Embryonic Stem Cell line- cultures of cells that came from 1 blastula
Embryonic and adult stem cells both come from nature, and
We study Gametes through a Karyotype
Each pair is called a homologous pair
Diploid= 23 pairs of chromosomes and 46 total chromosomes (2n)
Haploid= 23 individual pairs
Mitosis- makes body cells, or asexual reproduction like cloning
Meiosis- makes sex cells
Crossing Over- Occurs in Prohpase I
- each group of 4 chromatids are called a tetrad.
Individual chromatids may wrap around eachother and pieces may break off and reattach to other chromatids. Genes on chromosomes may change places.
Causes recombiant chromosomes= get new arrangements of genes
This creates variation in offspring.
Look at pictures
Independent assortment- random separation of the homologous chromosomes. This results in genetic variation.
Crossing Over- Portions of chromatids may break off and attach to other chromatids.
Random Fertilization- Not knowing which egg the sperm with fertilize.
STEM CELLS
A stem cell is a cell whose job in the body isn’t determined yet.
Differentiate- gradually change into the destined cell type
Protein Products cause the stem cell to differentiate.
Skin- as they differentiate they move closer to the surface
Bone- they are construction workers
Nerve- these cells are made before birth
Skeletal Muscle Cell- cells made by myoblasts
Red blood cell- made by bone marrow
TOTIPOTENT STEM CELLS- (totipotent)- total power, cell that can become any cell.
Zygote- fertilized egg
Morula- solid ball of 16 cells
1-4 days for cell division
1-16 number of cells
PLURIPOTENT STEM CELLS- (pluripotent)- cell that can become several cell types
Blastula/Blastocyst- Hollow ball of cells with inner cell mass
4-14 days for cell division
100’s of cells
Embryonic stem cell- cells from the inner cell mass growing in a culture
Made by destroying blastula and removing inner cell mass.
Most debatable and easy to grow
Embryonic Stem Cell line- cultures of cells that came from 1 blastula
Embryonic and adult stem cells both come from nature, and