examining and classifying plants

Nancy Larson®

Science 4

Booklet B

Examiningand Classifying

Plants

Botany

Botanist

Teacher’s Edition

Science 4 3© Nancy Larson. All rights reserved.

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Vascular and Nonvascular Plants1 A group of cells that works together in an organism to perform a specific

function is called tissue. One type of tissue found in the roots, stems, and leaves of

most plants is vascular tissue. Plants with vascular tissue are called vascular plants.

Examples of vascular plants are trees, grasses, ferns, and vegetable plants such as

tomato plants.

2 Vascular tissue is made of cells that join together to form tube-like structures

that allow fluids to move throughout the plant. There are two types of vascular

tissue—xylem and phloem. The function of xylem tissue is to bring water and nutrients

from the roots, through the stem, and into the leaves of the plant. The function of

phloem tissue is to bring the food made in the leaves to all parts of the plant.

Cross Section of aCelery Stem

3 Plants that do not have xylem and phloem tissues are called nonvascular plants.

Nonvascular plants do not have roots to take up water. Instead, the leaves of the

plant absorb moisture from the air and from rainwater. Nonvascular plants are low-

growing plants and are usually found in damp, shady places. Because they do not need

to rely on a root system for water, nonvascular plants can grow on rocks or tree

trunks. Mosses are examples of nonvascular plants.

Celery

xyle

m

phlo

em

Lesson 12

(green)

leaves

(green)

stems

roots

(scientific drawing of

celery stem)

(blue)

(red)

Science 44 © Nancy Larson. All rights reserved.

This page may not be reproduced w

ithout permission of N

ancy Larson.

Lesson 13 How Plants Make Their Own Food

1 Plants make their own food through a process called photosynthesis. Most

photosynthesis occurs in cells in the leaves of plants. During photosynthesis, the

energy from sunlight is used to change water and carbon dioxide into glucose and

oxygen. Glucose, a form of sugar, is the plant’s food.

The Process of Photosynthesis

Water travels through the xylem from the roots to cells in the leaves.

Air, which contains carbon dioxide, enters the undersides of leaves through tiny openings called stomata.

Energy from sunlight is absorbed by chlorophyll in the chloroplasts of leaf cells.

Water and carbon dioxide are changed into glucose and oxygen.

Glucose travels through the phloem from the leaves to all parts of the plant.

Some of the oxygen leaves the leaf through the stomata.

(blue)

(orange)

(yellow)

(purple)

(red)

(green)

(yellow)(yellow)

CO2 (orange)

(orange)

O2 (green)

(green)

(blue)H2O (blue)

(red)C6H12O6 (red)

(blue) (orange) (yellow) (red) (green)

H2O CO2 C6H12O6 O2

(purple)

(purple)

water + carbon dioxide + energy (sunlight) glucose + oxygen


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How Plants Reproduce1 Most plants reproduce from seeds. Some plants, such as pine trees, have seeds in

cones. Other plants, such as sunflowers, have seeds that develop from flowers.

2 Plants that do not have seeds reproduce from spores. A spore is a single cell that

can grow into a new plant. Ferns and mosses are examples of plants that reproduce

from spores.

Plant Reproduction

Lesson 14

Plants

seeds spores

cones flowers

sunflowerspine trees ferns mosses


(brown)(brown)



ancy Larson.

3 Some plants that produce seeds or spores can also reproduce from parts of the

plant. Reproduction from a part of a plant, such as a stem or root, is called vegetative

reproduction.

Vegetative Reproduction

RhizomeRunner

ginger plantstrawberry plant

Tuber Bulb

onion plantpotato plant

aboveground stem

Lesson 14

underground stem or root

underground stem

underground stem

(shade one potato red) bud

(red)

(red) (red) (red)

(red)

(red)


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Gymnosperms1 Plants with seeds in cones are called gymnosperms. The largest group of

gymnosperms is called conifers. Most conifers have very narrow, pointed leaves, called

needles, that grow in pairs or bunches. Conifers are able to survive in harsh weather

conditions because their thin, narrow leaves allow less water to evaporate when it is

cold or dry. Conifers with needles include pines, firs, and spruces. Other conifers,

such as junipers and cedars, have short, flat, scaly leaves.

2 Most conifers are evergreens. Plants that are evergreen stay green and keep

their leaves throughout the year. A few conifers drop their leaves in the fall. Trees

that drop their leaves each year are called deciduous trees.

3 The rapid growth of conifers makes them an important renewable resource. The

wood from conifers provides lumber for building and pulp that is used to make paper.

Types of Conifers

Leaves of Conifers

cedar

Lesson 18

(tape leaves of conifers)

pinespruce




ancy Larson.

Life Cycle of Gymnosperms1 Gymnosperms grow from seeds. Seeds of gymnosperms begin in cones.

Gymnosperms have small male cones that produce pollen and larger female cones that

produce eggs. The male and female cones are the reproductive parts of the plant.

2 Wind carries pollen from male cones to female cones. The movement of pollen

from the male cones to the female cones is called pollination.

3 Pollen and eggs join together in the female cones. The joining of pollen and eggs

is called fertilization.

4 After fertilization, seeds begin to develop. During seed development, the

fertilized eggs develop into seeds inside the female cones.

5 When the seeds have fully developed, the female cone opens and releases the

seeds. The seeds are dispersed, or scattered. Seeds of gymnosperms usually have a

wing that allows the wind to carry the seeds away from the plant.

6 When a seed has the proper amount of warmth and water, it begins to grow, or

sprout. The sprouting of a seed is called germination. The seed contains stored food

to support the new plant until it can grow roots and leaves to produce its own food.

Not all seeds find favorable conditions needed to germinate.

7 A young plant, called a seedling, grows from a germinating seed. The seedling

begins with a root growing downward from the seed. A shoot that grows upward from

the seed becomes the stem and first leaves.

8 The seedling continues to grow until it becomes an adult plant. The adult plant

produces cones containing pollen or eggs, allowing the plant to reproduce and the life

cycle to continue.

Lesson 20


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Life Cycle of Gymnosperms

Seedling

Cone Development

Pollination

Seed DevelopmentGermination

Fertilization

Seed Dispersal

Adult Plant

Lesson 20

(brown)

(brown)

(green)

(green)

(brown)

(brown)

(largerorangedots)

F

F

(brown)(yellow dots)

FM

(brown)(orange dots)

(brown)

(red dots)

(brown)

(brown)

(green)

(yellow)

(blue)

(brown)

(red)




ancy Larson.

Flowers of Angiosperms1 An angiosperm grows from a seed that begins in a flower. The four parts of a

flower are the carpel, stamen, petal, and sepal.

2 A carpel—also called a pistil—is the female reproductive part of the flower.

Some flowers have only one carpel and others have many carpels. A carpel has three

parts—ovary, style, and stigma. The ovary is the part of the carpel that produces

eggs.

3 A stamen is the male reproductive part of the flower. The stamen has two

parts—anther and filament. The anther is the part of the stamen that produces pollen.

4 Petals surround the carpals and stamens. Some flowers have large, brightly

colored petals and others have very small petals that are not easily seen.

5 Sepals, which look like small leaves, are found at the base of many flowers.

Sepals are the protective covering for the flower bud before the flower opens.

Parts of a Flower

sepals

anther

filament style

ovary

stigma

petals

Lesson 21

stamenM

carpelF

(4 eggs)(orange)

(yel

low)

(red) (yellow)


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Life Cycle of Angiosperms1 Flower development of angiosperms begins with a flower bud, often enclosed in

sepals. During flower development, the sepals open, the petals grow larger, the ovary

produces eggs, and the anthers produce pollen.

2 The transfer of pollen from an anther to the ovary is called pollination. Animals

and wind help to pollinate flowers. Flowers pollinated by insects and birds usually have

brightly colored or large petals and are often scented. Flowers pollinated by the wind

usually have small petals that are not easily seen.

3 When pollen from an anther lands on a stigma of a flower, the pollen travels down

the style to reach the eggs in the ovary. The joining of pollen and eggs in the ovary is

called fertilization.

4 During seed development, fertilized eggs in the ovary grow into seeds. As the

seeds develop, the petals of the flower dry and fall away, and the ovary containing the

seeds develops into a fruit. Some plants, such as apple trees and tomato plants, have

fleshy fruits with seeds enclosed in soft outer layers. Other plants, such as pecan

trees and sunflowers, have dry fruits with seeds enclosed in hard outer coverings. The

function of a fruit is to protect the seeds while they are developing and to move the

seeds to new locations.

Seed Development

Lesson 22

Fleshy fruits

apple tomato

Dry fruits

sunflower seedspecans


5 The movement of seeds to new locations by wind, water, and animals is called

seed dispersal. Seeds with wings are often blown by the wind. Streams, rivers, and

rain can carry seeds to new locations. Fleshy fruits attract animals that eat the fruits

and spread the seeds. Dry fruits are often carried from the plant by animals such

as squirrels and birds. Some fruits and seeds are transported to new locations by

sticking to the coats of animals.

6 When a seed has the proper amount of warmth and water, it begins to grow, or

sprout. The sprouting of a seed is called germination. The seed contains stored food

to support the new plant until it can grow leaves to produce its own food.

7 A young plant, called a seedling, grows from a germinating seed. The seedling

begins with a root growing downward from the seed. A shoot that grows upward from

the seed becomes the stem and first leaves.

8 The seedling continues to grow until it becomes an adult plant. The adult plant

produces flowers containing pollen and eggs that allow the plant to reproduce and the

life cycle to continue.



ancy Larson.

Lesson 23


Life Cycle of Angiosperms

Seedling

Flower Development

Pollination

Seed DevelopmentGermination

Fertilization

Seed Dispersal

Adult Plant

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Lesson 23

(yellow)

(green)

(yellow)

(green)

(brown)

(yellow) (yellow andblack)

(yellow)

(orange dots)

(brown)

(brown)

(brown)

(green)

wind, water, animals


Leaves of Angiosperms1 A leaf of an angiosperm is often called a broad leaf. The leaf usually has two

parts—the leaf blade and the leafstalk. The leaf blade is the broad, flat part of the

leaf. The leafstalk attaches the leaf blade to the stem of the plant.

2 Veins in the leaf blade contain xylem and phloem tissues that carry water and

minerals to the leaf and transport the glucose produced in the leaf to other parts of

the plant. The large main vein that extends outward from the leafstalk is called the

midrib vein.

3 The edge of a leaf blade is called the leaf margin. The leaf margin may be smooth

or toothed. A toothed leaf margin looks similar to a saw blade.

4 Broad leaves are classified as simple leaves or compound leaves. A simple leaf is

an individual blade at the end of a leafstalk. Some simple leaves have lobes. A lobe is a

projection on a leaf.

5 A compound leaf is a leaf blade that is divided into leaflets on a leafstalk. Each

leaflet looks like a small leaf. The leaflets may be arranged in a feather-like pattern

called pinnate or in a finger-like pattern called palmate.

Leaf of an Angiosperm



ancy Larson.

Lesson 24

(leaf rubbing)

(description of leaf)


palmate(finger-like)

pinnate(feather-like)

Simple Leaves

Compound Leaves

1. 2. 3.

4. 5.

6. 7.

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Lesson 24

leaflet

lobed

smooth

lobed

toothed

toothedsmoothsmooth

midribvein

leafstalk

lobe


Dichotomous Key for Tree Identification1 A dichotomous key can be used to identify organisms. In a dichotomous key,

a choice of two characteristics is given at each level. The choices help lead to

identification of an organism. The dichotomous key shown below can be used to

identify a tree by examining its leaves.

Leaf of a Tree

Needle-like or scaly leafpp. 18–40* Broad leaf

Simple leaf Compound leaf

Not lobed Lobed Pinnate(feather-like)pp. 130–150

Palmate(finger-like)pp. 151–153

Smoothpp. 41–53

Toothedpp. 54–81

*Trees: A Guide to Familiar American Trees, Herbert S. Zim and Alexander C. Martin, St.

Martin’s Press, New York.



ancy Larson.

Lesson 25

With acornpp. 82–103

(84, 96)

No acornpp. 108–113,

116–129


Scientific Method1 The scientific method is an organized way scientists test an idea. It begins with a

question. The next step is to collect information about the question.

2 After information is collected, an educated prediction, called a hypothesis, is

made. A hypothesis is what you think, based on the information you have collected,

might be the answer to the question.

3 The next step is to design an experiment to test the hypothesis. The description

of the materials needed and the procedure to follow should be clear enough so that

someone else can repeat the experiment. In the experiment, all of the conditions

except the one being tested should remain the same. The conditions that are the same

are called control variables. The one condition that is different during the experiment

is called the independent variable.

4 Now conduct the experiment several times. The same materials and steps should

be used each time.

5 During the experiment, observe and record what happens. The observations

recorded are called data. Data can be written descriptions, drawings, or

measurements. Data can often be presented on a chart, diagram, or graph so that

everyone can review it easily.

6 After the data is recorded, it is time to analyze the data and write a conclusion. The

conclusion should state whether your hypothesis was correct or not correct and how the

conclusion is supported by the data. After the experiment is completed, new questions can

be investigated on the basis of the results of the experiment.

Analyze data and write a conclusion

Design and conduct experiment

Observe and record data

Ask a question Make a hypothesisCollect information

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Lesson 15




ancy Larson.

Question: Will adding salt to water affect the growth of roots on a cutting?

Hypothesis:

I predict that salt affect the growth of roots on a cutting.

Design of the Experiment:

Control variables: cuttings from same plant, type of containers, amount of water, location of containers

Independent variable: presence or absence of salt in the water

Materials: 2 clear containers, water, salt, spoon, cuttings from a plant

Steps or procedures used to conduct this experiment:1. Put the same amount of water in each container. Add a spoonful of salt to

one container. Stir or swirl to dissolve salt. Label the containers.2. Put the same number of cuttings in each container.3. Put the containers in the same location near light.

(will/will not)

Record Data:

Date Observations

Rooting Plants in Salt Water ExperimentLesson 15


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Analyze the Data: What happened in this experiment?

What is a new question you could investigate?

Conclusion: What did you learn from this experiment?

Lesson 15

S4(1e)-SB-002S4(1e)-SBTM-002

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examining and classifying plants

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