Chapter 3; Lesson 3.4

T.O.C:How Angiosperms Reproduce

Flower Parts• Angiosperms vary in number, shape,

and color of their reproductive parts.• Petals of different flowers give each a

unique appearance• They are vascular plants that produce

flowers. Grasses & grains have flowers so small that they are hard to see. Oak trees have flowers that don’t look like flowers. Others have large showy flowers and even some fruits)

Flower Parts• Petals- largest & most noticeable part of flower. Helps protects

other parts of the flower. Often bright & smells good to attract insects & other animals

• Sepals- below petals, smaller, may look like green leaves. Before flower blooms the sepals protect the bud as it develops. Spread apart as flowers bloom

• Stamens- in the center of the flower, several stem-like structures. The male reproductive organ. Has 2 parts:– Anther- produces pollen grains– Filament- stalk that connects anther to the plant

• Pistil- at center of the flower. Female reproductive organ. Has 3 parts:– Stigma- at top. Sticky structure that captures pollen grains as

they fall on it. – Style- middle part. Connects stigma to ovary– Ovary- base of pistil. Inside ovary is Ovules- contain egg cells

which develop into seeds if fertilized

Flowers & Pollination• Pollination-(w.w) 1st step in angiosperm

reproduction. Occurs when pollen from an anther lands on the stigma of a flower of the same kind. – Self-pollination- occurs by transfer of pollen

w/in the same flower or between different flowers of the same plant.

– Cross-pollination- occurs by transfer of pollen from the anther of one plant’s flower to the stigma of a flower of the same kind of plant

• Fertilization- tube grows down from pollen grain thru style to the ovary. Sperm cells from pollen grains enter the ovules & join egg cells. Fertilized eggs develop into seeds. – As this happens, ovary forms a fruit that

surrounds & protects the seeds.

Flowers & Pollination• Pollination-(w.w) 1st step in angiosperm

reproduction. Occurs when pollen from an anther lands on the stigma of a flower of the same kind. – Self-pollination- occurs by transfer of pollen w/in

the same flower or between different flowers of the same plant.

– Cross-pollination- occurs by transfer of pollen from the anther of one plant’s flower to the stigma of a flower of the same kind of plant

• Fertilization- tube grows down from pollen grain thru style to the ovary. Sperm cells from pollen grains enter the ovules & join egg cells. Fertilized eggs develop into seeds. – As this happens, ovary forms a fruit that surrounds

& protects the seeds.

Flowers & Pollination continued• Flowers have brightly colored petals &

strong scents. • Nectar- sweet liquid produced by

flowers that some animals use as food. Plants that are pollinated by animals have flowers that produce heavy sticky pollen. – Why is this?

• Plants not pollinated by animals rely on the wind to carry pollen to other flowers. (these usually produce large amounts of pollen)

Fruits & Seeds• All angiosperm seeds are surrounded by fruit• Fruit-(w.w) ripened ovary of a flowering plant

– Monocotyledons- monocots- have one seed leaf– Dicotyledons- dicots- have 2 seed leafs

• Seed leaves store food for the embryo plant inside the seed.

Types of Fruit:– Aggregate fruits- made of many fruitlets. Develop

from one pistil. Ex: strawberries– Pome- seeds in core, Ex: Apples/pears– Berry- has seeds throughout flesh of single enlarged

ovary– Drupe- has single seed with hard covering Ex:

plum/cherry/peaches– Multiple fruit- made of pistils of several flowers on

same plant. Ex: Pineapple

Asexual Reproduction• When plants reproduce w/out seeds• Produces new plants identical to whole plants.

Types of Asexual Reproduction• Leaf cuttings- leaves from parent plant are placed

in water or soil can develop into new plants. • Runners- long slender limbs that grow close to the

ground & put out roots & shoots, create daughter plants Ex: Strawberries

• Bulbs- produce underground stems called bulbs that divide. Each section grows into new plant. Ex: tulips

• Tubers- underground stems that swell to store food. Have “eyes” that are buds which can form new plants Ex: potatoes

• Grafting- joining parts of 2 plants to form 1 new plant w/ of parents. Ex: roses, citrus trees

Lesson 3.4 Review Q’s 14 Points

1. What is a fruit? (2 points)2. What is the first step in angiosperm

reproduction? What are the 2 ways this can be done? (3 points)

3. Explain why birds/bees are important for flower reproduction. (2 points)

4. What are the male reproductive parts of a flower called? (3 points)

5. What are the female reproductive parts of a flower called? (4 points)