Angiosperms:

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Angiosperms

• Flowering plants the seeds are born within a
  fruit

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Facts about angiosperms

• They are the most abundant plants on earth today
• They are the most diverse plants on earth today

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Facts about angiosperms

• 240,000 known species6 times the number of
  species of all other plant groups combined
• Live in all sorts of habitats, from fresh water
  to desert, from icy north to steamy tropics
• Size ranges from almost microscopic to over 100
  meters tall

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Why are angiosperms important to us?

• They provide us with clothing, food, medicines,
  and other commercially valuable products.
• Can you think of a few cash crops that are
  angiosperms?

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Important terms

• Diploid- cell condition in which two of each type
  of chromosome is present
• Ovules- the structure that contains the female
  gametophyte and has the potential to develop into
  a seed
• Pollen tube- a tube that forms when a pollen
  grain lands on the stigma and germinates. The
  tube grows, passing between the cells of the
  stigma and the style to reach the egg inside the
  ovule, where fertilization occurs
• Gametophyte- haploid generation of the
  alternation of generations life cycle in a plant
  produces gametes that unite to form a diploid
  zygote

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Alternation of generations

• The sporophyte bears flowers. The flower
  produces microspores within anthers and
  megaspores within ovules by meiosis. A megaspore
  becomes a female gametophyte, which produces an
  egg within an embryo sac, and a microspore
  becomes a male gametophyte (pollen grain), which
  produces sperm. Fertilization results in a
  seed--enclosed zygote, and stored food.

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Generalized flower parts

• Petals (Corolla)
• Stamen
• Anther
• Filament
• Style
• Stigma
• Ovary
• Pistil (Carpel)
• Sepal (Calyx)

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Generalized flower parts

• Petals (Corolla)
• A flower part that occurs just inside the sepals
  often conspicuously colored to attract
  pollinators.

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Generalized flower parts

• Stamen
• The portion of the flower that consists of a
  filament and an anther containing pollen sacs
  where pollen is produced

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Generalized flower parts

• Anther
• Pollen-bearing portion of the stamen
• Filament
• The elongated stalk of a stamen

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Generalized flower parts

• Stigma
• Portion of the carpel where pollen grains adhere
  and germinate before fertilization can occur
• Style
• Elongated, central portion of the carpel between
  the ovary and the stigma

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Generalized flower parts

• Pistil (carpel)
• Ovule-bearing unit of the flowering plant
  stigma, style, and ovary together
• Ovary
• The enlarged, ovule-bearing portion of the carpel
  that develops into a fruit

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Generalized flower parts

• Sepal
• Outermost, sterile, leaf-like covering of the
  flower usually green in color

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Whats in a name?

• We call these plants angiosperms because their
  ovules are contained within diploid tissue
  (unlike gymnosperms)
• Angio comes from Greek meaning vessel this
  refers to the ovary which forms a fruit. This is
  a unique angiosperm feature

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Ovule of angiosperm
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Pollination of Angiosperms

• Occurs via insect,
• Or via animal,
• Or via wind,
• Even by water!

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Lifecycle of an orange

• Oranges and citrus fruits are very popular around
  the world. Navel oranges are actually quite
  rare! Those annoying seeds are vital.

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Stage 1 Seeds

• The seeds are scattered by wind, animals, or
  water. With fruit like oranges, most likely they
  are distributed by animals. Can you guess how?

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Stage 2 Germination

• When the weather is right and there is enough
  (but not too much) water the seed begins to
  germinate.
• What three things does a seed need to germinate?

Water Oxygen Correct temperature
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Stage 3 Seedling

• The plant begins to grow its first leaves and
  stems. The plant is still fragile at this time.

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Stage 4 Juvenile

• The plant grows very quickly, putting on new
  leaves, stems, and branches.

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Stage 5 Flowering

• Growth slows as the plant begins to produce
  flowers
• Flowering can be triggered by the time of year or
  the weather, particularly temperature

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Stage 6 Pollination

• Pollen grains are taken from flower to flower by
  bees and other flying insects. The mixing of
  pollen in known as pollination.

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Stage 7 Fruiting

• After a flower has been pollinated, the flower
  grows into a seed and fruit.

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Stage 8 Dispersal

• Animals (including us) eat the fruit, taking the
  seeds away from the orange tree.