B4 Revision 113 Questions GCSE Gateway Biology B

Contents 1. Who planted that there? … 10 questions 2. Water, water everywhere … 19 questions 3. 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

Chapter 1 Who Planted That There? 10 Questions Back to contents page

Identify the parts of a plant cell Question 1 Identify the parts of a plant cell ? Cell wall Cytoplasm ? Cell membrane ? Nucleus ? Vacuole ? Chloroplasts ?

Question 2 What is the role of chloroplasts? To absorb light energy for photosynthesis

Where does photosynthesis mainly occur? 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

What is given out by photosynthesis? Oxygen through leaf pores Question 5 What is given out by photosynthesis? Oxygen through leaf pores

Locate the parts of a leaf Question 6 ? ? Locate the parts of a leaf ? ? ? ? ? ? ? ? ?

How are leaves adapted to photosynthesis? Question 7 Broad, so large surface area Thin, so short distance for gases to travel Contain chlorophyll to absorb light Have a network of veins for support and transport Stomata for gas exchange How are leaves adapted to photosynthesis?

The exchange of gases in the stomata is by ? 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 10 How 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

Question 10 How is the cellular structure of a leaf adapted for efficient photosynthesis? 2. Thin cuticle made of wax . . . To protect the leaf without blocking out light

Question 10 How is the cellular structure of a leaf adapted for efficient photosynthesis? 3. Palisade cell layer at top of leaf . . . Contains most of the chloroplast, to absorb more light

4. Air spaces in the spongy layer. . . Question 10 How is the cellular structure of a leaf adapted for efficient photosynthesis? 4. Air spaces in the spongy layer. . . Allow carbon dioxide to diffuse between the stomata and photosynthesising cells, and increase the surface area

Question 10 How is the cellular structure of a leaf adapted for efficient photosynthesis? 5. Palisade cells contain many chloroplasts. . . To absorb all the available light

Water, Water Everywhere Chapter 2 Water, Water Everywhere 19 Questions Back to contents page

Question 1 How does water move in and out of plant cells? Through the cell wall and membrane

What is the role of the plant cell wall? Question 2 What is the role of the plant cell wall? To provide support

A lack of water can cause…? Question 3 A lack of water can cause…? Plants to droop (wilt)

Describe how water travels through a plant Question 4 Absorption from soil through root hairs Transport through the plant to the leaves Evaporation from the leaves (transpiration) Describe how water travels through a plant

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) What is osmosis?

Question 7 Osmosis is a type of ? Diffusion

‘partially permeable’ Question 8 A membrane that allows some small molecules to pass through but not larger molecules Explain the term ‘partially permeable’

Question 9 What is essential for the support of plants? The inelastic wall and water

What is so special about root hairs? Question 10 By increasing the surface area, root hairs increase the ability of roots to take up water by osmosis What is so special about root hairs?

Transpiration provides plants with water for…? Question 11 Cooling Photosynthesis Support 4. Movement of minerals Transpiration provides plants with water for…?

Question 12 How is a leaf adapted to reduce excessive water loss? Waxy cuticle 2. Small number of stomata on upper surface

Question 13 An animal cell does not have a cell wall It will: Swell and burst (lysis) when too much water enters Shrink, causing crenation, when too much water leaves Describe the effects of water uptake and loss on animal cells

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 The shrinking of a plant cell due to loss of water, the cell membrane pulls away from the cell wall Explain the term ‘plasmolysis’

Question 18 Plant cells which are full of water with their walls bowed out and pushing against neighbouring cells are turgid Explain the term ‘turgid’

Question 19 Changes in guard cell turgidity to regulate stomatal apertures 2. Number, distribution, position and size of stomata How is the cellular structure of a leaf adapted to reduce water loss?

Chapter 3 Transport In Plants 10 Questions Back to contents page

Water and mineral uptake, anchorage Question 1 What 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

What is the function of xylem? Question 3 Transpiration, movement of water and minerals from the roots to the shoot and leaves What is the function of xylem?

What is the function of phloem? Question 4 Translocation, movement of food substances (sugars) up and down stems to growing and storing tissues What is the function of phloem?

Question 5 What do xylem and phloem form? Continuous systems in leaves, stems and roots

Question 6 Thick strengthened cellulose wall with a hollow lumen (dead cells) Describe the structure of xylem

Describe the structure of phloem Columns of living cells Question 7 Describe the structure of phloem Columns of living cells

The evaporation and diffusion of water from inside leaves Question 8 What is transpiration? The evaporation and diffusion of water from inside leaves

Question 9 Transpiration rate is increased by…? Increase in light intensity 2. Increase in temperature 3. Increase in air movement 4. Decrease in humidity Transpiration rate is increased by…?

Question 10 Why 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

Question 10 Why does the rate of transpiration 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

Question 10 Why does the rate of transpiration 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

Question 10 Why does the rate of transpiration 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 Plants Need Minerals Too 19 Questions Back to contents page

Fertilisers contain mineral such as …? Question 1 Nitrates Phosphates Potassium 4. Magnesium compounds Fertilisers contain mineral such as …?

Question 2 Poor plant growth may be caused by …? A lack of one or more minerals in the soil

Dissolved minerals are absorbed by …? 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

Why do plants require phosphates? For respiration and growth Question 5 Why do plants require phosphates? For respiration and growth

Question 6 Why do plants require potassium compounds? For respiration and photosynthesis

Why do plants require magnesium compounds? Question 7 Why do plants require magnesium compounds? For photosynthesis

What would a lack of nitrate cause? Poor growth and yellow leaves 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 What would a lack of potassium cause? Poor flower and fruit growth, and discoloured leaves

What would a lack of magnesium cause? Question 11 What would a lack of magnesium cause? Yellow leaves

Question 12 Where are minerals usually present? In soil, in quite low concentration

Why is nitrogen required? To make amino acids and proteins Question 13 Why is nitrogen required? To make amino acids and proteins

Why is phosphorus required? To make DNA and cell membranes 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)

Why is magnesium required? Question 16 Why is magnesium required? To make chlorophyll

How are minerals taken up into root hair cells? Question 17 How are minerals taken up into root hair cells? By active transport

Describe active transport Question 18 Active transport can move substances from low concentration to high concentration Describe active transport

Active transport uses energy from …? Question 19 Active transport uses energy from …? Respiration

Chapter 5 Energy Flow 16 Questions Back to contents page

An organism that makes organic material 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

What do plants produce when they photosynthesise? Question 4 What do plants produce when they photosynthesise? Biomass

Name three fuels that come from biomass Question 5 Name three fuels that come from biomass Wood Alcohol Biogas

What is a pyramid of numbers? Question 6 A diagram to show the number of living organisms present at each trophic level in an ecosystem What is a pyramid of numbers?

What is a pyramid of biomass? Question 7 A diagram to show the masses of living organisms present at each trophic level in an ecosystem What is a pyramid of biomass?

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 Heat from respiration 2. Egestion

Question 10 Name two methods of transferring energy from biomass 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 What does the word ‘trophic’ mean?

Question 12 The shape of a pyramid of biomass shows that the energy level decreases with increasing trophic level Explain how the efficiency of energy transfer explains the shape of pyramids of biomass

Question 13 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 Explain how the efficiency of energy transfer the limited length of food chains

What is the formula to calculate the efficiency of energy transfer ? Question 14 Efficiency = Energy used for growth ÷ Energy supplied What is the formula to calculate the efficiency of energy transfer ?

Give three reasons for developing biofuels Question 15 Give three reasons for developing biofuels Renewable 2. Reduces air pollution 3. Energy self-reliance

Discuss choice of use of biofuel 2. Feeding it to livestock Question 16 Discuss choice of use of biofuel Eating it 2. Feeding it to livestock 3. Using it as a fuel 4. Growing the seeds

Chapter 6 Farming 22 Questions Back to contents page

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 1. Greenhouses 2. Hydroponics 3. Fish farms 4. Battery hens Some farmers use special methods to increase their production of food such as …?

1. No artificial fertilisers Describe organic farming methods Question 5 1. No artificial fertilisers 2. No herbicides 3. No pesticides Describe organic farming methods

By introducing a new predator or removing an old one Question 6 Describe how pests can be controlled biologically by introducing predators By introducing a new predator or removing an old one

Describe intensive farming Question 7 Trying to produce as much food as possible from the land, plants and animals available Describe intensive farming

What is an advantage of intensive farming? 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 What are disadvantages of intensive farming?

Describe how plants can be grown without soil (hydroponics) 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 Use of animal manure and compost 2. Crop rotation 3. Use of nitrogen-fixing crops 4. Weeding 5. Varying seed planting times Describe organic farming techniques

Explain an advantage of biological control No harmful chemicals used 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 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 Explain how removing one organism from a food chain or web may affect other organisms

Question 16 How do intensive food production improve the efficiency of energy transfer by reducing energy transfer? Reduce energy transfer to competing plants 2. Reduce energy transfer to pests 3. Reduces heat loss from animals

Because there are fewer weeds in crops Question 17 Explain how intensive food production improves the efficiency of energy transfer … 1. To competing plants? Because there are fewer weeds in crops

Question 17 Explain how intensive food production improves the efficiency of energy transfer … 2. To pests? Because there are fewer pests to attack and east crops or cause disease in livestock

Question 17 Explain how intensive food production improves the efficiency of energy transfer … 3. As heat? Because less heat is lost from animals kept in sheds and their movement is restricted

How can pesticides accumulate in food chains? Question 18 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 How can pesticides accumulate in food chains?

Question 19 1. Better control of mineral levels 2. Better control of disease Describe two advantages of hydroponics

Question 20 1. Lack of support for plants 2. Requires additional fertilisers Describe two disadvantages of hydroponics

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 Describe three advantages of organic farming methods

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

Chapter 7 Decay 9 Questions Back to contents page

Question 1 What four things are needed in the process of decay? 1. Presence of micro organisms 2. Temperature 3. Oxygen 4. Moisture What four things are needed in the process of decay?

Question 2 How can materials be recycled? Materials can decay and can therefore be recycled

Question 3 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 Describe an experiment to show that decay is caused by decomposers (bacteria and fungi)

Question 4 Name two things that micro organisms can be used for 1. Breaking down human waste (sewage) 2. Breaking down plant waste (compost) Name two things that micro organisms can be used for

Name six food preservation techniques that reduce the rate of decay Question 5 1. Canning 2. Cooling 3. Freezing 4. Drying 5. Adding salt / sugar 6. Adding vinegar Name six food preservation techniques that reduce the rate of decay

What do detritivores feed on and give examples? 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 8 Explain 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

The high temperature kills bacteria Question 8 Explain how the following food preservation method reduces the rate of decay … 2. Cooling The high temperature kills bacteria

Question 8 Explain how the following food preservation method reduces the rate of decay … 3. Freezing Freezing kills and slows down the growth of others. Freezing food stops bacteria from reproducing

Without water, bacteria and fungi cannot feed and grow Question 8 Explain how the following food preservation method reduces the rate of decay … 4. Drying Without water, bacteria and fungi cannot feed and grow

This is an example of osmosis Question 8 Explain how the following food preservation method reduces the rate of decay … 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

Question 8 Explain how the following food preservation method reduces the rate of decay … 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

An organism that breaks down dead organic matter Question 9 Explain the term ‘saprophyte’ An organism that breaks down dead organic matter

Chapter 8 Recycling 8 Questions Back to contents page

As plants and animals grow, what happens? 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 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 Explain how carbon is recycled in nature

Question 4 Explain how nitrogen is recycled in nature 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 Explain how nitrogen is recycled in nature

What percentage of the air is nitrogen Question 5 What percentage of the air is nitrogen 78%

Why can nitrogen not be used directly by animals or plants? Question 6 Why can nitrogen not be used directly by animals or plants? It is too unreactive

What do soil bacteria and fungi release and how? 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 Marine organisms make shells made of carbonates 2. Shells become limestone 3. Carbon returns to air as carbon dioxide during volcanic eruption or weathering Explain how carbon is recycled in the sea

End Of B4 Revision Back to contents page