Classification of living organisms

Everything in the world can be divided into three groups: some are living now, others were once alive, and some were __________.

never alive.

Scientists who study living organisms are called __________.

biologists.

There is an estimated total of __________ types of living organisms on the Earth.

8.7 million.

The sorting of living organisms into groups based on their similarities and common characteristics is called __________.

classification.

Biologists have classified all living organisms into five groups called __________.

kingdoms.

The protist kingdom includes organisms that have a very simple __________.

structures.

Bacteria are important because many of them break down __________ animals and plants.

dead.

The kingdom Monera includes __________ and blue-green algae.

bacteria.

Protists can make their own food because they have __________.

chlorophyll.

Fungi obtain nutrients from other sources by growing on __________ they can use.

dead plants or animals.

The multicellular organisms that contain green substance called chlorophyll are __________.

plants.

Mosses reproduce by making __________; they do not make seeds.

spores.

Ferns are bigger plants than __________.

mosses.

Conifers produce __________ which are formed inside the cone.

seeds.

Flowering plants are further divided into two major groups based on their __________ structure.

seed.

A monocot flower has __________ petals or a number which is divisible by three.

three.

The xylem and phloem are well organized in the stems of __________ plants, in the form of a ring.

dicot.

All leaves have networks of __________ for nutrient transport.

veins.

The underground part of the plant that makes up the roots is called __________.

roots.

Animals can be classified into two main groups: invertebrates and __________.

vertebrates.

Invertebrates do not have a bony skeleton with a __________.

backbone.

Sponges are the simplest form of __________.

animals.

Insects are characterized by having segmented bodies and a hard __________.

external skeleton.

Vertebrates have a __________, bony internal skeleton.

hard.

Fish breathe through __________.

gills.

Amphibians spend part of their life in __________ and part on land.

water.

Reptiles lay eggs with thick __________.

shells.

Birds are the only animals that have __________.

feathers.

Mammals are covered with __________ and hair.

fur.

Threats to biodiversity include deforestation, hunting, and __________.

pollution.

Extinction is the disappearance of __________ when all members die.

species.

Species in danger of becoming extinct are called __________ species.

endangered.

To conserve endangered species, one should say no to buying products made from __________ animals.

endangered.

Reforestation is an action that helps in __________ ecosystems.

conserving.

There are more than __________ different kinds of animals.

one million.

Monocots are not usually __________.

woody.

Dicots often have very brightly colored and scented __________.

flowers.

Plants vary in __________ and sizes.

shapes.

The __________ kingdom includes mushrooms and yeast.

Fungi.

The organisms in the animal kingdom obtain energy for life processes by eating __________ and plants.

other animals.