B6 - Microscopic life in water

Question 1

Why are algal blooms dangerous?

Answer 1

Algal blooms are dangerous because they release toxins into the water as they decompose.

Question 2

What are the two types of plankton?

Answer 2

The two types of plankton are:

• phytoplankton
• zooplankton

Question 3

What are phytoplankton?

Answer 3

Phytoplankton are microscopic plants.

Question 4

What are zooplankton?

Answer 4

Zooplankton are microscopic animals.

Question 5

Why are phytoplankton producers?

Answer 5

They are producers because they photosynthesise to make food.

Question 6

What happens to the number of plankton in winter?

Answer 6

The number of plankton in winter decreases as the water gets cold.

Question 7

What are advantages to living in water?

Answer 7

• organisms do not dry out, so there is no dehydration
• in a large volume of water there is less variation in temperature during the year
• organisms can grow bigger
• organisms can dispose of waste without losing water

Question 8

What are the disadvantages to living in water?

Answer 8

• organisms can find it difficult to maintain water balance in their cells
• some organisms find it difficult to move against the currents

Question 9

When phytoplankton levels drop, why do zooplankton levels drop?

Answer 9

Because zooplankton feed on phytoplankton so they will have less food.

Question 10

What is a contractile vacuole?

Answer 10

A structure in amoeba that removes excess water.

Question 11

Describe the process of amoeba removing excess water.

Answer 11

1) energy is used to collect excess water in small vacuoles
2) small vacuoles merge to form a large contractile vacuole
3) the contractile vacuole bursts, emptying its contents

Question 12

What are grazing food webs?

Answer 12

Grazing food webs are food webs that begin with green plants.

Question 13

What is marine snow?

Answer 13

Marine snow is organic matter that falls from the surface of oceans to the depths where it is used for feed.

Question 14

Wha tare the different types of water pollution?

Answer 14

• organic matter from sewage
• oil from factories or oil tankers at sea
• PCB’s from old electrical equipment
• fertilisers from farms
• pesticides from farms
• detergents from homes and factories

Question 15

How does air pollution affect aquatic life?

Answer 15

Burning fossils fuels can cause acid rain which can turn lakes acidic and kill animals in the lake.

Question 16

What is eutrophication?

Answer 16

Eutrophication is the process of water becoming rich in fertilisers, causing algae to bloom and block sunlight preventing creatures and plants from photosynthesising/surviving.

Question 17

What are biological indicators?

Answer 17

Organisms which live in water - their presence tells scientists how polluted the water is.

Question 18

What are the problems with DDT and PCB’s?

Answer 18

They are not broken down by the body and therefore accumulate over time.