Childrens Illustrated Encyclopedia

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Biology

Botany

the study of plants and flowers is

called botany. It is one of the two

main branches

of biology.

the natural world is full of marvels

and mysteries: the beautiful colors of a

flower, the magnificent display of a peacock,

the magic of new life when a child is born.

Biology is the science of all living things,

from the tiniest microscopic organisms

(living things) to the largest whales in the

sea; it is the study of all plants and animals

and their environments, or surroundings.

Biologists study how living things grow, feed,

and move, how they reproduce, and how they

evolve (change) over long periods of time.

Biology covers an enormous range of topics and

deals with millions of species (kinds) of organisms.

Because of this, biology is divided into different

specialized branches, such as anatomy, which

deals with the structure of living things, and physiology, which is

concerned with the way animals and plants function. Biology is important

in other sciences and professions that deal with living things, such as

agriculture, forestry, and medicine.

hIstory of BIology

the greek philosopher aristotle was one of

the first biologists. he studied birds and

animals in about 350 bce. during the 17th

century, the english scientist robert hooke

discovered living cells through the newly

invented microscope. In 1953, english

scientist francis Crick and american

scientist James watson discovered the

structure of deoxyribonucleic acid

(dna), the chemical that controls all

cells and life patterns.

human BIology

human biology is

concerned with

all the different

systems of the

human body.

these include the

digestive system, the

circulatory system, the

respiratory (breathing) system,

the reproductive system, the

nervous system, and the

muscular and skeletal systems.

Clump of a frog’s

newly laid eggs,

called frogspawn

Zoology

Zoology, the other

main branch of

biology, is the

scientific study

of animals.

taxonomy

Biologists classify living

organisms into different

groups so they can understand

the relationships between them.

this is called taxonomy. for

instance, butterflies and moths

belong to the same taxonomic

group, called lepidoptera.

Francis Crick (left) and James Watson

Botanists study the

structure of plants and

how they reproduce.

Stamen of flower

laBoratory

a biologist works in a specially

equipped room called a laboratory.

Biologists use a variety of techniques to

study animals and plants. they may

dissect (cut up) specimens or use

powerful microscopes to probe into

the structure of tiny microscopic

organisms, such as cells and bacteria.

Zoologists

study the

life and growth

of animals.

Chemistry

darwin, charles

evolution

genetics

human body

Plants

reproduction

EvEryday biology

there are biological processes going on all

around us. for example, bread dough rises when

it is left in a warm place. this is because live yeast

in the dough gives off gas that makes the dough

expand, a process called fermentation.

Carbon dioxide gas

makes the dough rise.

Cross-section

of stamen

Tiger pierid butterfly

of Central and

South America

Once the bread is cooked, it is full of

little holes made by the gas bubbles.

Yeast is made up of single-celled living organisms.

Yeast cells obtain their energy from the dough mixture

and give off carbon dioxide gas in the process.

Hairstreak

butterfly of

South America

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