chapter 4 plants. lesson 1 how do leaves help a plant? leaves are organs made of cells and tissues ...
TRANSCRIPT
Chapter 4
Plants
Lesson 1 How do leaves help a plant?
Leaves are organs made of cells and tissues Plants make their own food called glucose Leaves contain various tissues. Each tissue
has a particular cells that perform certain roles
Leaves have openings in the bottom to let air in and out
Plants make their own food. They are called PRODUCERS Producers- organisms that make their own
food. Humans are consumers. Consumers- CANNOT make their own
food. Most of a plant’s food is made in its
leaves. The top layer of a leaf is smooth and this
protects the plant. The bottom layer of a leaf looks like a
sponge. It has spaces that air can pass through.
Parts of a Leaf
PhotosynthesisThe process in which plants make sugar
for food Plants perform photosynthesis by using:
Carbon dioxideWaterSunlight
Photosynthesis occurs in the chloroplastsChloroplasts make the plant green
Sunlight provides the cells the energy they need for photosynthesis.
A plant’s roots get the water. The water enters the chloroplasts. Carbon dioxide comes from the atmosphere
(air). Carbon dioxide enters the plant through its
leaves (bottom). Carbon dioxide then enters the chloroplasts. The water and carbon dioxide combined are
used to make sugar. Photosynthesis makes OXYGEN for humans and
animals. Photosynthesis also makes GLUCOSE (sugar) for
plants to grow. This means that plants make glucose (sugar),
their food, during the day. They don’t use all of their food during the day;
they save some for night time.
Cellular respiration- plants use oxygen with food to get the energy they need for growth, repairs, and reproduction
Sugar moves from the leaves to other parts of the plant where it is stored and later provides energy. It also forms cellulose, a chemical that makes up the strong cell walls.
Carbon dioxide + water + sunlight → oxygen + sugar
Lesson 2How do stems and roots help a plant?
Stems- plant organs that hold leaves, flowers, and fruit on a plant
Xylem and phloem tissues are tubes that transport substances within vascular plants
Stems Leaves grow on stems. Stems are plants’ organs (heart,
kidney). Stems help leaves get more sunlight. Stems also hold fruit and flowers on
plants. Some stems have thorns (roses). Thorns are a plant’s protection. A thorn is a sharp point. There are two kinds of stems:
Woody stems (trees and bushes) Non-woody stems (dandelions)
Parts of a Stem Inside a stem there are
tubes that transport (carry) things: Minerals Water Nutrients
There are two types of tubes: Xylem Phloem
XylemTubes that carry AWAY water and
minerals from the roots to the leaves.
The roots take water from the soil.The water has minerals in it that
came from the soil (like fertilizer).Plants use these minerals for
photosynthesis.
PhloemThese are tubes that carry sugar
from the leaves to the rest of the plant.
In trees, the phloem is the innermost layer of the bark.
The bark protects the phloem.
RootsRoots are plant organsThey grow in the groundRoots are strongThey hold the plant in placeRoots also help the plant get
WATER from the ground
Different Kinds of Roots Taproots- a large root that grows
straight down Fibrous root- many roots grow out in all
directions / the roots divide into smaller and smaller roots
Lesson 3 How do plants reproduce?
Parts of a flower: Petals- colorful outer area of the flower Stamen- the male part of the flower (a
single flower may have many stamens) Anthers- tissues at the top of each stamen
(where pollen is located) Filament- holds the anthers
Pistil- the female part of the flower (has a bottle-like shape) Stigma- receives pollen during civilization Ovary- female reproductive organ
Pollination Pollination is the moving of pollen from
the stamen to the pistil But how is this possible if plants don’t
move? Wind, insects (bees), water, birds, and
even bats can move pollen Flowers attract these organisms to come
and eat the flower When they rub against the flower,
stamen cells attach to them
When they go to another flower, they drop the pollen down to the pistil
They join with egg cells in the pistil This is called fertilization (just like how
babies are made) DNA carries information about how a
plants looks and works The sperm cell has half of the male
parent’s DNA The egg has half of the female parent’s
DNA This DNA combined causes new plants
to look similar to their parents
Seeds Parts of a seed:
Seed coat- protects the embryo Embryo- where the new plant is formed Endosperm- surrounds the embryo
A seed has one or two cotyledons. Seeds of plants with one cotyledon are called monocots, while seeds of plants with two cotyledon are called dicots
http://www.brainpop.com/science/diversityoflife/seedplants/
Spreading Seeds Seeds can be spread through a variety
of ways Animals Humans Wind Water
Affects rate of plant growth: DNA Environment
Spores Spores are single plant cells that are not
fertilized like seeds, but can grown into a new plant.
Many plants reproduce asexually, (with only one parent)
Some plants can reproduce both sexually and asexually
There are some plants that are cones that contain seeds. These seeds are moved through wind, birds, insects, etc. and these help spread the seeds.
Monocot & DicotMonocot Dicot
A monocot seed, like corn, has one area of stored food, while a dicot has two areas that are easily split apart such as a bean
A monocot has veins that are parallel, while a dicot’s veins branch out
Most monocots have fibrous root systems. Most dicots have taproot systems.