Transcript Cell Division

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What are cells?
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Cells are the basic units of structure and
function in living things.
◦ Cells are the building blocks that make up any
living organism.
◦ Each cell has a special job to help an organism
survive and reproduce.
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Living organisms have anywhere from 1 to
billions of cells.
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The Nucleus is the brain of the cell.
The chromosomes are rode like structures in
the nucleus that contain the DNA.
Humans have 46 chromosomes in each cell.
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Bats-44
Potatoes-48
Camels-70
Flies-8
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Reproduction
◦ Single celled organisms and other asexually
reproducing organisms divide their cells when
reproducing.
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Growth and Repair
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Mitosis is when a normal cell divides into two
identical cells.
Each daughter cell has the same number of
chromosomes as the parent cell.
All normal cells go through mitosis.
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Cell division that makes gametes.
One cell splits into four cells, each with half
the number of chromosomes as the parent
cell.
◦ Human sperm and egg cells have 23 chromosomes.
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Only gametes (sexual reproduction) go
through meiosis.
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Normal body cells have 46 chromosomes that
come in pairs.
◦ Homologous Chromosomes
◦ Diploid Cells
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Gametes only have one chromosome from
each pair.
◦ Haploid Cells
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Artificial asexual reproduction.
A body cell is taken from an organism and
the nucleus is removed.
The nucleus is transplanted into an egg cell
of the same organism.
When the egg develops, it is a genetic clone
of the original organism.
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DNA cloning-only a small portion of an
organisms DNA is copied and “pasted” into
another organism. The new DNA begins to
replicate.
Reproductive cloning-making an exact copy
of an organism.
◦ Sheep, pigs, cows, cats and rabbits.
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Embryo cloning-cloning the human embryo
to harvest and study stem cells.