Many Plants Reproduce With
Flowers and Fruit
• ANGIOSPERMS HAVE FLOWERS AND
FRUIT
• ANIMALS SPREAD BOTH POLLEN
AND SEEDS
• HUMANS DEPEND ON PLANTS FOR
THEIR SURVIVAL
– Land animals rely on plants for food & oxygen
(and materials).
Angiosperms: Flower & Fruit
• Angiosperms are seed plants that make flowers
and fruit (peanuts, grapes, strawberries, roses,
grass etc,); most plants are angiosperms
• Sperm of a flowering plant are protected in a
pollen grain & don’t need water to get to egg.
• Eggs develop into embryos that are enclosed
within seeds.
• Both angiosperm & gymnosperm have male &
female reproductive structures; sometimes on
same plant or sometimes male & female plants.
• Angiosperms have sperm & egg in flowers
• Flower = reproductive part of angiosperm; egg
forms in ovary & if fertilized forms seed(s) with
ovary becoming fruit around the seed(s).
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ANGIOSPERM
FLOWER
Anther= male part (meiosis forms sperm within
pollen grains)
Pistil= female part (meiosis forms egg cells within
ovary)
Pollen grains released & if caught on pistil grows a
pollen tube into ovary
Sperm travels via p. tube to ovary to fertilize the egg
(grows into embryo & forms seed coat)
Ovary forms into fruit around seed(s); may fall to
ground or be eaten by animal. If lands in place
where it can germinate & survive, will grow into a
new plant.
Asexual reproduction may also occur in angiosperms
by root shoots or “runners” forming new plants.
Angiosperms: Flowers
• Flowers vary in color, shape, size & scent.
• In some species, male & female parts are on
different flowers, & sometimes separate male &
female trees/plants.
• Sepals: leafy structure enclosing flower before it
opens.
• Petals: leafy structures around the pistil, usually
colorful (attract pollinators)
• Stamen: male part including stalk (filament) and
anther tip (makes sperm inside of pollen grains)
• Pistil: female part- ovary is at the base with egg
cells. Top of pistil= stigma (pollen grain attaches)
Angiosperms: Fruit
• Fruit: a ripened plant
ovary, may have more
than 1 seed (apple)
• Fleshy fruit has juicy
flesh (cherry,corn)
• Dry fruit (nuts, wing
fruit of maple tree,
feathery dandelion &
sunflowers). May have
shells to protect them or
structures to transport
them.
Animals spread Pollen & Seeds
• As animals eat, they move pollen from flower to
flower & seeds are transported.
• Animals that pollinate flowers are pollinators.
Bees are very important ones.
• Relationship between angiosperms & pollinators
can be very specific (hummingbirds with long
beaks for some)
• Animal pollinators bring it to where it is needed
most (bee to another flower) while wind
pollination scatters it everywhere.
• Many seeds go through animals digestive tract
(after fruit is eaten) & deposited in its waste (to
help scatter seeds widely)
• Dry fruit seeds (burrs) catch on fur & are spread.
Humans Need Plants to Survive
• Land animals rely on plants for food & oxygen (and
materials).
• All organisms need energy to live; animals get it via
food. Plants & algae capture energy from Sun to make
sugars and oxygen (photosynthesis). Angiosperms are
main food supplier & algae main oxygen supplier.
Animals need oxygen to release energy stored in food.
• Plants are an important source of natural resources
(natural gas/coal from plant remains under ground;
soil made from rocks broken down partially by plant
roots & decayed plants)
• Plants provide wood (lumber & paper) cotton
(clothes) aspirin & other drugs made based on
chemicals originally found in plants.