Objective: You will be able to draw the early stages of development.

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Objective You will be able to draw the early
stages of development.

• Do Now
• Read Fertilization on p. 1016
• Define fertilization
• Define Zygote

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Fertilization

• Meiosis creates sex cells with a monoploid number
  of chromosomes
• When a sperm and an egg unite it restores the
  diploid number of chromosomes
• The new cell that is formed is called a zygote

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Egg Cell
Sperm Cell
n
n
Fertilization
2n
Zygote
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Cleavage

• The first few divisions after fertilization are
  called cleavage
• Is the cell division done by mitosis or meiosis?
• Cleavage ends up creating a hollow ball of cells
  called the blastula

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Figure 47.6x Sea urchin development, from
single cell to larva
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Figure 47.0 Human embryo
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Figure 46.18 Human fetal development
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Activity

• We will be viewing the stages of cleavage in an
  animal under the microscope.
• Begin viewing the slide under the microscope
• You will need to find the following stages
• -Zygote -Two cell -Four cell
• -morula -blastula -gastrula
• For each stage draw what you see in your notebook

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Objective You will be able to identify and give
the function of the parts of an egg.
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Fertilization

• External fertilization is when the egg and sperm
  unite outside the female
• Ex. Fish and frogs
• Internal fertilization is when the egg and sperm
  unite inside the female
• Ex. Reptiles, birds and mammals

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Development

• All animals need to grow in water otherwise they
  will dry out
• External fertilization happens in the water
• Mammals have water environment inside the female
• Reptiles and birds have internal fertilization
  but lay eggs
• The egg contains the watery environemnt

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What came first the chicken or the egg?
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Egg parts

• Amnion- Fluid filled and surrounds the embryo
• Allantois- Stores the waste produced by the
  embryo
• Yolk Sac- Stores nutrient-rich food
• Chorion- Regulates O2 going to embryo and CO2
  leaving embryo

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Figure 3912 The Male Reproductive System
Section 39-3
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Figure 46.8 Reproductive anatomy of the human
male (continued)
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Figure 3914 The Female Reproductive System
Section 39-3
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Figure 46.9 Reproductive anatomy of the human
female (continued)
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Figure 46.16 Formation of the zygote and early
postfertilization events
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Menstrual Cycle

• Occurs in women at the onset of puberty
• Refers to the cycle in which an egg is released
  and the uterus is prepared for pregnancy

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Figure 46.13b Oogenesis
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Concepts

• Involves three glands
• Hypothalamus
• Pituitary
• Ovaries
• Involves many hormones including
• Releasing hormone
• FSH and LH
• Estrogen

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The phases

• Follicular phase- Involves the thickening of the
  uterus by estrogen
• Makes egg grow in follicle
• Ovulation- Is the release of the egg from the
  ovary
• Caused by LH
• Luteal phase- Is the creation of the corpus
  luteum which will maintain the pregnancy
• Caused by LH
• Menstruation- Shedding of the uterus if
  pregnancy does not occur

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Sex Hormones

• Testosterone
• Cause the male secondary sex characteristics
• Estrogen
• Cause the female secondary sex characteristics

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Figure 38.2 Review of an idealized flower
Pistil
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Objective You will be able to identify and give
the function of the parts of a flower.

• Do Now
• Read pages 612 and 613
• For each part of the flower, write its function
• This will take you a few minutes

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Male parts

• Male part is called the stamen
• The stamen consist of the anther and filament
• Anther
• Carries out meiosis to make pollen
• Sperm cells are inside the pollen
• Filament
• Holds the anther into the air

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Female parts

• Female part is called the pistil
• The pistil is made of the stigma, style and ovary
• Stigma is sticky to capture the pollen
• Style is a passageway to the ovary
• Ovary
• Carries out meiosis to make eggs
• The eggs are found within ovules

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Objective You will be able to describe the
events of pollination and fertilization.

• Do Now
• Read page 616
• What two things form from fertilization?

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Figure 38.5 Pollen grains have tough, ornate,
and distinctive walls
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Pollination

• Pollination is the transfer of the pollen from
  the anther to the stigma
• If the pollen lands on a flower on the SAME plant
  it is called self-pollination
• If it lands on a different individual then it is
  called cross-pollination
• Pollinators are used to move the pollen

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Figure 38.3d1 Pollination modes
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Figure 38.1 Simplified overview of angiosperm
life cycle
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Fertilization

• Fertilization occurs within the ovule
• There are actually two sperm cells
• The first will fertilize the egg and form a
  zygote
• This zygote will undergo cleavage to from an
  embryo

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Fertilization

• The second sperm will fertilize a 2n cell and
  form a 3n cell called the endosperm
• The endosperm is the food source for the embryo
• This concept of two fertilizations is called
  double fertilization
• It is unique to flowering plants.

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After Fertilization

• The ovule itself will harden and become a seed
• The ovary itself will change and become a fruit
• The fruit is used for seed dispersal

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Figure 38.12 Development of a pea fruit (pod)
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Objective You will be able to identify and
describe the parts of a seed.

• Do Now
• Read page 618
• Give examples of fruits that everyone thinks are
  vegetables.

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Figure 38.11 Seed structure
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Seed Structure

• The embryo consists of the hypocotyl and the
  epicotyl
• Hypocotyl becomes the root
• Epicotyl becomes the leaves and upper part of
  stem
• Cotyledon is used as a food source
• The seed coat protects the seed

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Seed germination

• Once proper conditions are met, the seed will
  start to germinate.
• Seed germination depends on water, oxygen and
  temperature
• Why not light?