Science Exam Lesson 4

What are the 3 main types of unicellular organisms?

Bacteria, Protozoa, and Unicellular Fungi

Name 1 helpful kind of bacteria and 1 harmful type of bacteria.

Good – bacteria in your intestine that help you break down food

Bad – E. Coli, listeria, and salmonella

List 3 different characteristics of protozoa.

They live in water

B. They can move and hunt for food

C. They range in size from 10 mim to 20 cm.

What is 1 characteristic of unicellular fungi? What benefits do

unicellular fungi have on humans?

The most common unicellular fungi is yeast. Some forms of yeast are

used to make beer and bread. They are used in cancer research

because they are easy to grow.

List 3 different characteristics of amoebas.

A. They can alter their shape

B. They can be found in the protozoa, unicellular fungi, algae, and

animal groups

C. They can be seen with a light microscope

What is phagocytosis?

This is how unicellular organisms feed. The organisms extend their

pseudopods (tentacles) to surround their food. The pseudopods

connect and brings the food inside the organism for digestion.

How do unicellular organisms move?

A. They move by using their pseudopods

B. Some have flagella (hair-like structures) that move rapidly

How do unicellular organisms reproduce?

Asexual reproduction- they duplicate everything inside themselves and

split in two

How do unicellular organisms exchange gases (breathe)?

They breathe through diffusion. Diffusion is the movement of

substances from an area of high concentration (many) to an area of

low concentration (not much).

How do multicellular organisms feed?

A. Fungi – break down food outside of themselves and then absorb

the nutrients

B. Plants – Photosynthesis

C. Animals – they consume food through their mouth and digest the

food internally

How do multicellular organisms move?

A. Plants – they cannot move by themselves

B. Animals – they walk on 1 or more limbs

What 2 ways do multicellular organisms reproduce?

A. Fungi – asexual reproduction  make clones of themselves

B. Plants and animals  sexual reproduction  2 organisms make 1

organism

13. What are gametes?

Gametes are the cells produced by the parents and then are fertilized

to produce an offspring.

Explain gas exchange in multicellular animals.

A. Algae – diffusion

B. Rest of the animals – O2 (oxygen) is sent through the nose or

mouth and into the lungs (alveolus). From there (O2) oxygen is sent into the

blood stream. (CO2) Carbon dioxide is removed from the blood and exhaled through

the mouth or nose. Fish use gills to get oxygen from the water.

Explain gas exchange in multicellular plants.

A. Algae – diffusion

B. Water plants – water passes over the plant and provides CO2. The plant

then releases oxygen into the water

C. Land Plants – CO2 enters and O2 exits through tiny holes in the leaves

called stomata