Biology 10(Abeka) chap 4

Primary Function of Flowers

To make seeds for reproduction.

Pedicel

The flower stalk.

Receptacle

The end of the pedicel where flower parts attach; designed to hold developing seeds.

Sepals

Leaf-like structures (usually green) attached to the edge of the receptacle; protect the flower bud.

Petals

Most conspicuous part of the flower; attract pollinators.

Stamens

Male organs within the corolla that produce pollen.

Pollen

Contains the sperm cell of the plant.

Filament

Long, narrow stalk that supports the anther.

Anther

Enlarged structure at the tip of the filament; produces pollen.

Pistil

Female part of the flower; vase-shaped structure.

Ovary

Swollen base of the pistil; contains ovules.

Ovules

Structures within the ovary that contain egg cells.

Complete Flower

Has sepals, petals, stamens, and pistils.

Incomplete Flower

Missing one or more of the four main flower parts.

Bracts

Leaf-like structures in place of petals.

Staminate Flower

Flower that has only stamens.

Pistillate Flower

Flower that has only pistils.

Monoecious Plant

Plant that produces both staminate and pistillate flowers on the same plant.

Dioecious Plant

Plant that produces staminate and pistillate flowers on separate plants.

Inflorescences

Flowers arranged in clusters.

Photoperiodism

Chief factor controlling flowering; response to length of daylight and night.

Other Flowering Factors

Temperature and soil fertility.

Stigma

Top part of the pistil where pollen lands.

Fruit

A fully ripened ovary.

Requirements for Fruit Formation

Pollination and fertilization.

Vegetable

Term applied to fruits that are not sweet.

Pollination

Transfer of pollen from anther to stigma.

Self-Pollination

Pollination within the same flower.

Cross-Pollination

Pollination between different plants.

Nectar

Sweet, watery liquid produced by plants.

Fertilization

Sperm cell from pollen fuses with egg cell in the ovule.

Gametes

Sperm and egg cells.

Embryo

Result of sperm uniting with egg cell.

Endosperm

Tissue surrounding the fertilized egg; nourishes the growing embryo.

Double Fertilization

Process where two sperm cells are involved: one forms the embryo, one forms the endosperm.

Simple Fruit

Forms from one flower with one pistil.

Berries

Entire ovary is fleshy and juicy throughout; examples: tomatoes, grapes, cucumbers, watermelons, oranges.

Drupes

Fleshy and juicy but not entirely; contain an inner woody layer called a stone; examples: peaches, plums, cherries, walnuts.

Pomes

Outer fleshy layer with an inner papery core; example: apples.

Legumes

Dry fruits consisting of a pod enclosing several seeds; not fleshy; examples: peas, beans, peanuts.

Samaras

Small dry seeds with wing-like structures; examples: maples, ashes, elms.

Nuts

Seeds enclosed in a hard shell; examples: chestnuts, hickory nuts, hazelnuts.

Achenes

Small dry fruits with a single seed and thin shell.

Grains

Fruits of the grass family.

Cereal Grains

Most important fruits used by man; wheat is the most important.

Simple Fleshy Fruits

Berries, drupes, pomes.

Simple Dry Fruits

Legumes, samaras, nuts, grains, achenes.

Aggregate Fruit

Form from one flower that has several pistils

Woody Stem

A stem that contains wood and supports perennial plants such as trees and shrubs.

Bud

A part of the stem that contains undeveloped leaves or flowers.

Terminal (Apical) Bud

Bud located at the tip of the stem; when it grows, the stem increases in length.

Lateral (Axillary) Bud

Bud located on the side of the stem; produces branching.

Bud Scale

Protective covering that shields the bud from frost injury and drying out during winter.

Bud Scale Scars

Rings that circle the stem; indicate where last year's growth began.

Node

Area where leaves are growing or have grown.

Lenticels

Small openings in the bark that allow air to enter the stem for respiration.

Primary Growth

Growth in length at the tips of branches.

Apical Dominance

Terminal bud produces hormones that control and limit the growth of lateral buds.

Spire-like Branching

Tree grows tall and straight with branches coming from a long central shaft; examples: pines, firs, hemlock, redwood, cypress.

Spreading Branching

Tree has several main branches usually close to the ground; examples: willows, cottonwoods, elms.

Bark

Provides protection and transportation for the stem.

Cork

Strong protective tissue forming the outer bark.

Phloem

Carries food and liquids downward through the plant.

Sieve Tubes

Conduct food throughout the plant within the phloem.

Companion Cells

Strengthen phloem tissue and assist sieve tubes.

Vascular Cambium

Layer of cells that produces new xylem and phloem.

Wood

Provides strength and support; transports water and minerals from roots to leaves.

Lignin

Substance that stiffens wood and strengthens cell walls.

Tracheids

Water-conducting cells found in conifers.

Vessels

Large xylem tubes found in broadleaf trees; more efficient than tracheids.

Conifers

Cone-bearing trees; contain only tracheids.

Angiosperms

Flowering plants; contain both tracheids and vessels.

Secondary Growth

Growth in width of the stem.

Pith

Center of a young woody stem; loosely packed cells functioning mainly for water storage.

Heartwood

Older inner wood; provides structural support only.

Sapwood

Younger outer wood; actively conducts water and minerals.