B4 Revision

B4 Revision

GCSE Gateway Biology B

113 Questions

Contents1. Who planted that there? … 10 questions

2. Water, water everywhere … 19 questions3. Transport in plants … 10 questions

4. Plants need minerals too …19 questions

5. Energy flow … 16 questions

6. Farming … 22 questions

7. Decay … 9 questions

8. Recycling … 8 questions

Who Planted That There?

Chapter 1

10 Questions

Back to contents page

Question 1

Identify the parts of a plant cell

?

?

??

?

?

Cell wallCytoplasm

Cell membrane

Nucleus

ChloroplastsVacuole

Question 2

What is the role of

chloroplasts?

To absorb light energy for

photosynthesis

Question 3

Where does photosynthesis mainly occur?

In the leaves

Question 4

What 2 things are needed for photosynthesis

?

Water thought the roots

Carbon dioxide through leaf

pores

Question 5

What is given out by

photosynthesis?

Oxygen through leaf

pores

Question 6

Locate the

parts of a leaf

?

?

?

?

? ? ?

?

?

?

?

Question 7

How are leaves adapted to

photosynthesis?

1. Broad, so large surface area

2. Thin, so short distance for gases to travel

3. Contain chlorophyll to absorb light

4. Have a network of veins for support and transport

5. Stomata for gas exchange

Question 8

The exchange of gases in the stomata is by ?

Diffusion

Question 9

How is the structure of a leaf palisade cell related to its function?

It contains many

chloroplasts

Question 10How is the cellular structure of a leaf adapted for efficient photosynthesis?

(Complete the sentence)

1. Epidermis is thin and transparent . . .

To allow more light to reach the palisade cells


2. Thin cuticle made of wax . . .

To protect the leaf without blocking out light


3. Palisade cell layer at top of leaf. . .

Contains most of the chloroplast, to absorb more light


4. Air spaces in the spongy layer. . .

Allow carbon dioxide to diffuse between the stomata and photosynthesising cells, and

increase the surface area


5. Palisade cells contain many chloroplasts. . .

To absorb all the available light

Water, Water Everywhere

Chapter 2

19 Questions


Question 1

How does water move in

and out of plant cells?

Through the cell wall and membrane

Question 2

What is the role of the plant cell

wall?

To provide support

Question 3

A lack of water can cause…?

Plants to droop (wilt)

Question 4

Describe how water travels

through a plant

1.Absorption from soil through root hairs

2.Transport through the plant to the leaves

3.Evaporation from the leaves (transpiration)

Question 5

Healthy plants must do what?

They must balance water

loss with water uptake

Question 6

What is osmosis?

The movement of water across a partially

permeable membrane from an area of high

concentration ( ie. dilute solution) to an area of high concentration (ie. concentrated solution)

Question 7

Osmosis is a type of ?

Diffusion

Question 8

Explain the term

‘partially permeable’

A membrane that allows some

small molecules to pass through but not larger

molecules

Question 9

What is essential for

the support of plants?

The inelastic wall and water

Question 10

What is so special about

root hairs?

By increasing the surface

area, root hairs increase the

ability of roots to take up water

by osmosis

Question 11

Transpiration provides

plants with water for…?

1. Cooling

2. Photosynthesis

3. Support

4. Movement of minerals

Question 12

How is a leaf adapted to

reduce excessive

water loss?

1. Waxy cuticle

2. Small number of stomata on upper surface

Question 13

Describe the effects of water uptake and loss on animal cells

An animal cell does not have a cell wall

It will:

1.Swell and burst (lysis) when too

much water enters

2.Shrink, causing crenation, when too much water leaves

Question 14

How are plants supported by

the turgor pressure within

cells?

By the wall pressure acting

against inelastic cell

wall

Question 15

What is essential for

the support of plants?

The inelastic wall and water

Question 16

Explain the term

‘flaccid’

floppy

Question 17

Explain the term

‘plasmolysis’

The shrinking of a plant cell due to loss of water, the cell

membrane pulls away from the

cell wall

Question 18

Explain the term

‘turgid’

Plant cells which are full of water with their walls bowed out and

pushing against neighbouring

cells are turgid

Question 19

How is the cellular

structure of a leaf adapted to reduce water

loss?

1.Changes in guard cell turgidity to

regulate stomatal apertures

2. Number, distribution,

position and size of stomata

Transport In Plants

Chapter 3

10 Questions


Question 1What is the role of the …

Stem:Support, transport

Leaf:Photosynthesis

Flower:Reproduction

Root:Water and mineral uptake, anchorage

Question 2

Describe the arrangement of

xylem and phloem in a

dicotyledonous root, stem and

leaf

Vascular bundles

Question 3

What is the function of

xylem?

Transpiration, movement of

water and minerals from

the roots to the shoot and

leaves

Question 4

What is the function of phloem?

Translocation, movement of food

substances (sugars) up and down stems to growing and

storing tissues

Question 5

What do xylem and phloem

form?

Continuous systems in

leaves, stems and roots

Question 6

Describe the structure of

xylem

Thick strengthened cellulose wall with a hollow lumen (dead cells)

Question 7

Describe the structure of

phloem

Columns of living cells

Question 8

What is transpiration?

The evaporation

and diffusion of water from inside leaves

Question 9

Transpiration rate is

increased by…?

1.Increase in light intensity

2. Increase in temperature

3. Increase in air movement

4. Decrease in humidity

Question 10Why does the rate of transpiration

increase when …(Complete the sentence)

1. There is an increase in light intensity?

Because the stomata opens up. This allows more water to

escape


increase when …

2. There is an increase in temperature?

Because as the temperature increases, the random movement of water molecules increases and more

water escapes


increase when …

3. There is an increase in air movement?

Because wind causes more molecules near stomata to be

removed. This increases evaporation and diffusion from inside the leaf


increase when …

4. There is an decrease in humidity?

Because in dry conditions there is a very low concentration of water molecules outside the leaf. This

causes more diffusion of water from inside the leaf to the outside

Plants Need Minerals Too

Chapter 4

19 Questions


Question 1

Fertilisers contain mineral

such as …?

1. Nitrates

2. Phosphates

3. Potassium

4. Magnesium compounds

Question 2

Poor plant growth may be caused by …?

A lack of one or more

minerals in the soil

Question 3

Dissolved minerals are absorbed by

…?

The roots from the soil

Question 4

Why do plants require

nitrates?

For protein, which are

needed for cell growth

Question 5


phosphates?

For respiration and growth

Question 6


potassium compounds?

For respiration and

photosynthesis

Question 7


magnesium compounds?

For photosynthesis

Question 8

What would a lack of nitrate

cause?

Poor growth and yellow

leaves

Question 9

What would a lack of

phosphate cause?

Poor root growth and discoloured

leaves

Question 10


potassium cause?

Poor flower and fruit

growth, and discoloured

leaves

Question 11


magnesium cause?

Yellow leaves

Question 12

Where are minerals usually

present?

In soil, in quite low

concentration

Question 13

Why is nitrogen required?

To make amino acids and proteins

Question 14

Why is phosphorus

required?

To make DNA and cell

membranes

Question 15

Why is potassium required?

To help enzymes (in

photosynthesis and respiration)

Question 16

Why is magnesium required?

To make chlorophyll

Question 17

How are minerals taken

up into root hair cells?

By active transport

Question 18

Describe active transport

Active transport can move

substances from low concentration

to high concentration

Question 19

Active transport uses

energy from …?

Respiration

Energy Flow

Chapter 5

16 Questions


Question 1

What does

‘producer’

mean?

An organism that makes

organic material

Question 2

What does

‘consumer’

mean?

Organisms in an ecosystem that use up organic

matter produced by other

organisms

Question 3

Where does the energy in a food chain

come from?

It comes from plants

absorbing sunlight

Question 4

What do plants produce when

they photosynthesise

?

Biomass

Question 5

Name three fuels that come from biomass

1. Wood

2. Alcohol

3. Biogas

Question 6

What is a pyramid of numbers?

A diagram to show the

number of living organisms

present at each trophic level in an ecosystem

Question 7

What is a pyramid of biomass?

A diagram to show the

masses of living organisms

present at each trophic level in an ecosystem

Question 8

How does energy from the

sun flow through food

chains?

By photosynthesis

and feeding

Question 9

Name two less useful forms that energy is transferred to

at each stage in the food chain

1. Heat from respiration

2. Egestion

Question 10

Name two methods of transferring energy from

biomass

1. Burning fast growing trees

2. Fermenting biomass using

bacteria or yeast

Question 11

What does the word

‘trophic’

mean?

The level at which an organism gets its food.

Primary producers are level one

Primary consumers are level two

Secondary consumers are level three

Question 12

Explain how the efficiency of energy

transfer explains the shape of pyramids of

biomass

The shape of a pyramid of

biomass shows that the energy level decreases with increasing

trophic level

Question 13

Explain how the efficiency of energy transfer the limited

length of food chains

As each trophic level ‘loses’ up to

90% of the available energy,

the length of a food chain is

limited to a small number of links

Question 14

What is the formula to calculate the

efficiency of energy transfer ?

Efficiency =

Energy used for growth

÷

Energy supplied

Question 15

Give three reasons for developing

biofuels

1. Renewable

2. Reduces air pollution

3. Energy self-reliance

Question 16

Discuss choice of use of biofuel

1. Eating it

2. Feeding it to livestock

3. Using it as a fuel

4. Growing the seeds

Farming

Chapter 6

22 Questions


Question 1

What do pesticides do?

Kill pests

Question 2

What do herbicides do?

Kill plants (weeds)

Question 3

Give two examples of

pesticides

1. Insecticides (to kill insects)

2. Fungicides (to kill fungi)

Question 4

Some farmers use special methods to

increase their production of

food such as …?

1. Greenhouses

2. Hydroponics

3. Fish farms

4. Battery hens

Question 5

Describe organic farming

methods

1. No artificial fertilisers

2. No herbicides

3. No pesticides

Question 6

Describe how pests can be

controlled biologically by

introducing predators

By introducing a new predator or removing an old

one

Question 7

Describe intensive farming

Trying to produce as

much food as possible from

the land, plants and animals

available

Question 8

What is an advantage of

intensive farming?

It is efficient

Question 9

What are disadvantages

of intensive farming?

1. It raises ethical dilemmas

2. Pesticides may enter and accumulate in

food chains

3. Pesticides may harm organisms which are

not pests

Question 10

Describe how plants can be grown without

soil (hydroponics)

The plant roots are in specially treated water that contains

the required amounts of

fertiliser and oxygen

Question 11

Describe possible uses

of hydroponics

1. Glasshouse tomato

2. Plant growth in areas of barren soil

Question 12

Describe organic farming

techniques

1.Use of animal manure and compost

2. Crop rotation

3. Use of nitrogen-fixing crops

4. Weeding

5. Varying seed planting times

Question 13

Explain an advantage of

biological control

No harmful chemicals used

Question 14

Explain a disadvantage of biological

control

Takes a long time and often do not kill all

the pests

Question 15

Explain how removing one

organism from a food chain or

web may affect other organisms

Some animal populations may increase because

fewer are eaten while others may decrease because predators

are short of food and have to eat something

else

Question 16

How do intensive food production

improve the efficiency of

energy transfer by reducing

energy transfer?

1. Reduce energy transfer to

competing plants

2. Reduce energy transfer to pests

3. Reduces heat loss from animals

Question 17Explain how intensive food production

improves the efficiency of energy transfer …

1. To competing plants?

Because there are fewer weeds in crops



2. To pests?

Because there are fewer pests to attack and east crops or cause disease in livestock



3. As heat?

Because less heat is lost from animals kept in sheds and

their movement is restricted

Question 18

How can pesticides

accumulate in food chains?

The pesticide in the organisms low

down the food chain gets passed

on to predators higher up in the

chain, and they get a lethal dose

Question 19

Describe two advantages of hydroponics

1. Better control of mineral

levels

2. Better control of disease

Question 20

Describe two disadvantages of hydroponics

1. Lack of support for

plants

2. Requires additional fertilisers

Question 21

Describe three advantages of

organic farming methods

1. Expensive chemicals do not have to be

bought

2. No chemical build pollution or build up

in food chains

3. Some people think the products taste

better

Question 22

Describe two disadvantages

of organic farming methods

1. Biological control methods are slow

and do not kill pests

2. Crop yields are reduced and cost of products are

higher

Decay

Chapter 7

9 Questions


Question 1

What four things are

needed in the process of

decay?

1. Presence of micro organisms

2. Temperature

3. Oxygen

4. Moisture

Question 2

How can materials be

recycled?

Materials can decay and can therefore be

recycled

Question 3

Describe an experiment to

show that decay is caused by decomposers (bacteria and

fungi)

1. Two samples of soil are collected

2. One sample is heated but not burned

3. Both samples are weighed and then put in sealed flasks containing

limewater

4. After two days the soil samples are re-weighed

5. Only the fresh soil sample loses mass

6. The limewater in the flask containing the fresh soil turns from clear to

milky.

7. This shows that carbon dioxide is produced

Question 4

Name two things that

micro organisms can

be used for

1. Breaking down human waste

(sewage)

2. Breaking down plant waste (compost)

Question 5

Name six food preservation

techniques that reduce the rate

of decay

1. Canning

2. Cooling

3. Freezing

4. Drying

5. Adding salt / sugar

6. Adding vinegar

Question 6

What do detritivores feed on and

give examples?

They feed on dead and decaying

material (detritus), such as

earthworms, maggots, woodlice,

etc

Question 7

How do detritivores increase the

rate of decay?

They produce larger surface

area

Question 8Explain how the following food

preservation method reduces the rate of decay …

1. Canning

The food is heated to kill bacteria. The food is then put into cans and sealed while it is

still hot. This forms a vacuum and prevents the entry of oxygen and bacteria



2. Cooling

The high temperature kills bacteria



3. Freezing

Freezing kills and slows down the growth of others. Freezing food stops bacteria from

reproducing



4. Drying

Without water, bacteria and fungi cannot feed and grow



5. Adding salt or sugar

A high concentration of sugar or salt solution kills some bacteria and fungi and

stops the growth of others.This is an example of osmosis



6. Adding vinegar

Vinegar is an acid. Very few bacteria can grow in acid conditions.

Food such as pickled eggs and chutney are preserved in this way

Question 9

Explain the term

‘saprophyte’

An organism that breaks down dead

organic matter

Recycling

Chapter 8

8 Questions


Question 1

As plants and animals grow,

what happens?

They take in chemicals and

incorporate elements from these into their

bodies

Question 2

What happens when plants and animal

die and decay?

The elements are recycled. These

elements include:

• Carbon

2. Nitrogen

Question 3

Explain how

carbon is recycled in nature

1. Plants remove carbon dioxide from air by photosynthesis

2. Feeding passes carbon compounds along a food chain or web

3. Plants and animals release carbon dioxide into the air, as a product of

respiration

4. Soil bacteria and fungi, acting as decomposers, release carbon dioxide

into the air

5. Burning of fossil fuels (combustion) releases carbon dioxide

Question 4

Explain how

nitrogen is recycled in nature

1. Plants take in nitrates from the soil to make protein for growth

2. Feeding passes nitrogen compounds along a food chain

or web

3. Nitrogen compounds in dead plants and animal are broken down by decomposers into

nitrates and returned to the soil

Question 5

What percentage of

the air is nitrogen

78%

Question 6

Why can nitrogen not

be used directly by animals or

plants?

It is too unreactive

Question 7

What do soil bacteria and fungi release

and how?

Soil bacteria and fungi, acting as decomposers, release carbon dioxide into the

air by respiration

Question 8

Explain how

carbon is recycled

in the sea

1.Marine organisms make shells made of carbonates

2. Shells become limestone

3. Carbon returns to air as carbon dioxide during volcanic eruption or

weathering

End Of B4 Revision


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