PLANT REPRODUCTION

______________________ - the sexual reproductive organ of plants

Structure of flowers:

Essential parts

______________________ - produces male gametes

______________________ - produces female gametes

Most flowers have 3, 4, or 5 stamens. Each stamen consists of a filament and an anther. The anther produces the ______________________.

Most flowers contain only 1 pistil.

A pistil consists of an ovary which contains the ovule where the eggs are formed, a style, and a stigma, the sticky part that pollen is trapped by.

Nonessential flower parts contain neither male nor female parts. They are:

______________________ - the base

______________________ - green leafy structures that cover the bud.

______________________ - protect the stamens and pistils

______________________ = all the sepals together

______________________ = all the petals together

KINDS OF FLOWERS:

______________________ - contain all the essential and nonessential parts

______________________ - lack one or more of the essential or nonessential parts

Perfect Flowers - contain both ______________________

Imperfect Flowers - ____________ either stamens or pistils

FORMATION OF GAMETES:

Pollen Grain formation - Pollen grains are produced in pollen sacs inside the __________. Each pollen grain is composed of 2 cells, a larger cell called the tube cell, and a smaller cell called the generative cell.

Egg Cell formation - The egg is formed in the _________________ . Each ovule usually contains 8 nuclei, only one of which becomes the egg.

__________________-

The transfer of pollen from the anther to the stigma is called pollination. Flowers may self-pollinate or cross-pollinate.

Pollen may be transferred by _________, ____________, or ____________. Flowers that are pollinated by animals usually have brightly colored petals and/or fragrant smells.

_______-pollinated flowers are usually not showy and produce huge amounts of pollen.

_________ - The fertilization process begins when the pollen grain lands on the stigma. The tube cell in the pollen grain forms a pollen tube that grows through the stigma. The generative nucleus divides into two nuclei called sperm nuclei, which travel down the pollen tube to the ovary. One sperm nucleus fertilizes the egg. The other fertilizes the polar nuclei in the ovary to form the endosperm, a special food source for the egg. This is called double fertilization. The zygote grows into the embryo while the endosperm divides and grows, and the ovule forms a hard seed coat around the whole structure.

FRUITS AND SEEDS

As the seeds mature the ovary around the ovule matures into a fruit.

______________________ - a ripened ovary

Any part of the plant that contains the seeds is called the fruit.

Fruits may form in different ways.

__________ fruits - sugar is stored in soft tissues around the ovary

Pomes - seeds in papery ovary (apples)

Drupes - seeds in a hard pit (peaches)

Berries - seeds in soft flesh (grapes)

__________ fruits - such as nuts, beans, grains

Legumes - form pods (peas, beans)

Achenes - single seed inside hard shell but seed not attached to shell (sunflower, dandelion)

Grains - like achenes but firmly attached to shell wall (wheat, oats, rice)

Nuts - large seed, very heavy shell (walnut, acorns, pecans)

Winged fruit - samara (helicopters) (maples, ash, elms)

____________ fruit - form from one ovary

Aggregate fruit - from from flowers with many pistils (blackberries)

Multiple fruit - form from single fruits that form a single structure. (Pineapples)

Seeds may be spread by animals, wind, water, or mechanical means.

____________ - growth of the seed

____________ - a period of rest

The embryo plant consists of:

______________ - embryonic leaves

______________ - embryonic root

______________ - embryonic stem between the radicle and cotyledons

______________ - embryonic stem above the cotyledons

ASEXUAL REPRODUCTION

________________ propagation - occurs naturally

________________ propagation - producing new individuals from roots stems or leaves

Vegetative propagation occurs in:

__________ - horizontal, above-ground stems that produce adventitious roots and form new plants. (strawberries)

__________ - horizontal, underground stems that produce new plants from nodes in the stem (Iris)

__________ - modified storage stems such as the potato that can form new plants

__________ - short stems protected by scale-like leaves (onion)

Food-storing roots - capable of producing new stems (carrots)

Artificial propagation - occurs with the help of man

_________ - pieces of stem that are cut off and kept in water or soil

_________ - sections of stem or buds (the scion) are cut from one plant and attached to another plant (the stock)

Tissue culture - portions of the pith are grown in flasks of a growth medium until it forms a plant large enough to plant

Layering - a branch is folded down and covered with soil. After roots develop the plant is cut off.