Topic: Reproduction and Development

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Topic Reproduction and Development

• Aim How do cells divide?
• Do Now Explain the differences between sexual
  and asexual reproduction. What types of things
  reproduce sexually? Asexually?
• HW PAGE 96-97 10 MAIN POINTS FINISH HANDOUT

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What are the two types of reproduction?

• Asexual reproduction

• Sexual reproduction

MEIOSIS
MITOSIS
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What is ASEXUAL Reproduction?

• Requires one parent that divides
• Asexual Aparent
• Offspring are identical to parents
• Same of chromosomes

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How does ASEXUAL reproduction occur?

• MITOSIS cell division
• One cell divides into two identical daughter
  cells (same of chromosomes as parent)
• Occurs in all body cells EXCEPT sex cells

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What are the steps of Mitosis?

• Interphase
• Prophase
• Metaphase
• Anaphase
• Telophase
• Cytokinesis

IPMAT
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Interphase
CHROMATIN
The mass of DNA inside the nucleus during
interphase is known as CHROMATIN.
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Prophase
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Metaphase
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Anaphase
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Telophase
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What are the steps of Mitosis?

• INTERPHASE cell grows to mature size and
  chromatin replicate (makes copy of DNA)
• PROPHASE chromatin forms chromosomes, nuclear
  membrane disappears and spindle fibers form
• METAPHASE chromosomes line up in the Middle of
  the cell
• ANAPHASE chromosomes separate and move Away
  from each other
• TELOPHASE nuclear membrane starts to form

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What is Cytokinesis?

• Part of telophase
• Cell membrane pinches in (cytoplasm separates)
  resulting in 2 new cells

CYTOKINESIS
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How is mitosis different in plant cells?

• Cell membrane DOES NOT pinch in
• Instead a CELL PLATE forms between 2 new cells
• Plant cells do not have centrioles (animal cells
  do)

CELL PLATE
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Cytokinesis Animal and Plant
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What is Cancer?

• Abnormal and uncontrolled cell division

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What are the different types of ASEXUAL
Reproduction?

• Binary Fission one celled organism divides into
  two identical cells (mitosis)
• Binary Fission means equal division
• Examples ameba and paramecia
• Budding unequal division of organisms
• Examples hydra, yeast
• Sporulation spores (specialized cells) develop
  into new organisms (mitosis)
• Examples mold, mushrooms

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What are the different types of ASEXUAL
Reproduction?

• Vegetative Propagation Asexual reproduction
  used by plants
• Runners (strawberries)
• Buds (potatoes)
• Grafting (roses)
• Bulbs (onions)

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Binary Fission Budding
BINARY FISSION
BUDDING
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Sporulation
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Vegetative Propagation
RUNNERS
GRAFTING
BULBS
BUDS
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Topic Reproduction and Development

• Aim What is sexual reproduction?
• Do Now Why does sexual reproduction require two
  parents?

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What is sexual reproduction?

• Requires 2 parent cells, each with half the
  normal number of chromosomes
• Involves sex cells
• Human sperm egg ? zygote
• 23 23 ? 46

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What is meiosis?

• Cell division occurs only in sex organs to
  produce sex cells (sperm and egg)
• Produces 4 daughter cells with half the number of
  chromosomes as parent cell (23 in humans)
• 2 divisions (1 ? 2 ? 4)

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Meiosis
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How does meiosis occur in males?

• Occurs in testes to produce sperm
• Produces 4 new sperm cells

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How does meiosis occur in females?

• Occurs in ovaries
• Produces 1 egg cell and 3 polar bodies

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What is fertilization?

• Union of egg and sperm to form a zygote
• Two types
• Internal fertilization occurs inside the female
  (humans)
• External fertilization occurs outside the
  female (frogs) can occur on land or in water

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What happens to the zygote after fertilization?

• Zygote divides by MITOSIS to form 3 layers that
  will develop into different parts of the embryo
• Outer layer forms the skin and nerves
• Middle layer forms muscles
• Inner layer forms heart and stomach