Download PLANTS Plant Reproduction

Methods of Reproduction:
Reproduction in plants can be either asexual or sexual. Asexual Reproduction in Plants
• fragmentation • spore formation (ferns) ­ alternate generations Sexual Reproduction in Plants
Seeds are the product of sexual reproduction in most plants (seed=plant embryo). There are two types of seed forming vascular plants: • flowering plants (angiosperms)
• cone bearing plants (gymnosperms)
Sexual Reproduction in Plants
Sexual reproduction involves creating offspring that are genetically different from the parent(s).
The act of sexual reproduction in plants is called pollination and produces an embryo called a seed.
Pollination can be accomplished by using ...
­ wind ­ flying insects, birds, and bats
­ animals
... to transfer pollen from plant to plant.
Flowers are the sexual organs in MOST plants (angiosperms).
Plants do not have flowers (gymnosperms) use cones (i.e. pine trees).
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Sexual Reproduction in Plants
SEED = EMBRYO + FOOD • A seed can remain dormant and therefore will live through rough times while adult plants may die off. • This ensures the survival of the species. • Flowering Plants are more successful than conifers because they produce a protective coating around their seeds which increases the chance of the embryo surviving in rough times. Gymnosperms (Naked Seeds)
Gymnosperms are plants that produce naked seeds (mostly cone bearing plants) using their sexual reproductive organs.
Examples are pine trees, and spruce trees.
Pollination in gymnosperms: the pollen from the male cones are carried by the wind to the female cones to make seeds.
The seeds are protected by a structure similar to a maple key and fall to the ground to germinate and grow into new trees.
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The most common gymnosperms are Conifers.
Conifers have leaves called needles or scales. The leaves (needles) have a reduced surface area and have a thick waxy coat to reduce water loss and to prevent freezing.
Angiosperms (Protected seeds)
Angiosperms are vascular plants that produce protected seeds using flowers as their sexual reproductive organs.
Examples: tulips, apple trees, sunflowers
There are 2 types of angiosperms, (1) monocots and (2) dicots. 3
Angiosperms (Protected seeds)
dicot seed
monocot seed one cotyledon (1 seed leaf) two cotyledons (2 seed leaves) Angiosperms MONOCOTS • One cotyledon (1 Seed Leaf) • Leaves of 3 petals • Parallel Veins • Scattered Vascular Bundles DICOTS
• One cotyledon (2 Seed Leaves) • Leaves of 4 or 5 petals • Network Veins • Vascular Bundles in RINGS 4
Angiosperms Sexual Reproduction in Plants
Pollinators are flying insects, birds, and bats that transfer pollen from flower to flower.
Pollination in angiosperms: pollen is spread from the anther to the stigma of another plant (cross­pollination) or the same plant (self­pollination) by bees, insects, wind, etc. A pollen tube grows down the style into the ovary a sperm travels down the tube to fertilize one egg resulting in the development of a seed .
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Sexual Reproduction in Plants
Flowers contain ...
­ ovaries, which is where eggs (and seeds) are produced.
­ pollen, the "sperm" that fertilizes the egg
A fruit is the pollinated ovary containing mature seeds. Many flowering plants encourage direct and efficient pollen transfer by using ...
­ smell
­ colour ­ offering nectar
Angiosperms Fruit in angiosperms help to disperse seeds to reduce competition with parent plant.
Types of fruit:
Winged fruit – glides to new location (maple fruit)
Floating fruit – can float to new locations (coconut)
Fleshy fruit ­ sweet bright colored fruit have seeds that survive the digestive system of animals that eat the fruit (apple)
Spiny fruit­ Velcro like projections attach to the fur of animals (cockleburs)
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