KS3 Biology — Recall & Retrieval

Cells and organisation

1.

What is a cell?

A cell is the basic structural unit of a living organism.

2.

Why are cells described as the fundamental unit of living organisms?

Cells are the fundamental unit because all living organisms are made of one or more cells, and cells carry out the processes needed for life.

3.

What is a unicellular organism?

A unicellular organism is an organism made of only one cell.

4.

What is a multicellular organism?

A multicellular organism is an organism made of many cells.

5.

How can a light microscope be used to observe cells?

A light microscope uses lenses to magnify cells so that they can be seen.

6.

How can a cell image viewed through a light microscope be recorded?

A cell image can be recorded by drawing a labelled biological drawing or by taking a photograph through the microscope.

7.

What is the function of the cell wall?

The cell wall supports and strengthens a plant cell and helps it keep its shape.

8.

What is the function of the cell membrane?

The cell membrane controls what substances enter and leave the cell.

9.

What is the function of the cytoplasm?

The cytoplasm is where many of the chemical reactions needed for life take place.

10.

What is the function of the nucleus?

The nucleus contains the genetic material and controls the activities of the cell.

11.

What is the function of the vacuole?

The vacuole contains cell sap and helps maintain pressure inside a plant cell, helping it stay firm.

12.

What is the function of mitochondria?

Mitochondria are where aerobic respiration takes place, releasing energy for the cell.

13.

What is the function of chloroplasts?

Chloroplasts contain chlorophyll and are where photosynthesis takes place.

14.

Which cell structures are found in both plant and animal cells?

Plant and animal cells both contain a cell membrane, cytoplasm, nucleus and mitochondria.

15.

Which cell structures are found in plant cells but not animal cells?

Plant cells have a cell wall, chloroplasts and a large permanent vacuole, which animal cells do not have.

16.

What is diffusion?

Diffusion is the net movement of particles from an area of higher concentration to an area of lower concentration.

17.

In which direction do particles move during diffusion?

Particles move from a higher concentration to a lower concentration during diffusion.

18.

What role does diffusion have in moving materials into and out of cells?

Diffusion allows substances such as oxygen and carbon dioxide to move into and out of cells.

19.

How are some unicellular organisms structurally adapted to survive?

Unicellular organisms can have structures or features that help them obtain food, remove waste, move or exchange substances efficiently.

20.

What is a structural adaptation?

A structural adaptation is a physical feature of an organism that helps it survive in its environment.

21.

What is a tissue?

A tissue is a group of similar cells working together to carry out a particular function.

22.

What is an organ?

An organ is a group of different tissues working together to carry out a particular function.

23.

What is an organ system?

An organ system is a group of organs working together to perform a major function.

24.

What is an organism?

An organism is an individual living thing.

25.

What is the correct order of organisation from cells to organisms?

The correct order is cells → tissues → organs → organ systems → organism.

The skeletal and muscular systems

1.

What is the human skeleton?

The human skeleton is the framework of bones that supports and protects the body.

2.

What are the four main functions of the human skeleton?

The four main functions are support, protection, movement and blood cell production.

3.

How does the skeleton support the body?

The skeleton supports the body by providing a strong framework that holds the body upright.

4.

How does the skeleton protect internal organs?

Bones protect important internal organs, such as the skull protecting the brain and the ribs protecting the heart and lungs.

5.

How does the skeleton help the body move?

The skeleton provides attachment points for muscles, allowing muscles to move bones at joints.

6.

How does the skeleton help make blood cells?

Blood cells are made in bone marrow inside some bones.

7.

What is a joint?

A joint is a place where two or more bones meet.

8.

What is the function of a joint?

Joints allow bones to move relative to each other.

9.

What is cartilage?

Cartilage is a smooth, tough tissue found at the ends of bones at many joints.

10.

What is the function of cartilage at a joint?

Cartilage reduces friction and cushions the ends of bones as they move.

11.

What are ligaments?

Ligaments are strong bands of connective tissue that join bones to other bones.

12.

What is the function of ligaments?

Ligaments hold bones together and help stabilise joints.

13.

What are tendons?

Tendons are strong connective tissues that attach muscles to bones.

14.

What is the function of tendons?

Tendons transmit the force of a contracting muscle to a bone, causing movement.

15.

What is biomechanics?

Biomechanics is the study of how forces and movements affect living organisms, including how muscles and bones produce movement.

16.

How do muscles and bones work together to produce movement?

Muscles contract and pull on tendons, which pull on bones to produce movement at joints.

17.

What happens to a muscle when it contracts?

When a muscle contracts, it becomes shorter and usually thicker.

18.

How can the force exerted by a muscle be measured?

The force exerted by a muscle can be measured using a force meter or other suitable measuring device.

19.

What is an antagonistic pair of muscles?

An antagonistic pair is two muscles that work together to move a joint in opposite directions.

20.

Why do muscles work in antagonistic pairs?

Muscles work in antagonistic pairs because muscles can pull but cannot push.

21.

What happens when one muscle in an antagonistic pair contracts?

When one muscle contracts, it pulls the bone in one direction.

22.

What happens to the other muscle when its partner contracts?

The other muscle relaxes and is stretched as its partner contracts.

23.

What is an example of an antagonistic pair of muscles?

The biceps and triceps are an example of an antagonistic pair of muscles.

24.

How do antagonistic muscles move a bone in different directions?

One muscle contracts to pull a bone in one direction, while the opposing muscle contracts to pull it back in the other direction.

25.

Why are muscles needed to move bones?

Muscles are needed because bones cannot move themselves; muscles provide the forces that move bones.

Nutrition and digestion

1.

What are the seven components of a healthy human diet?

The seven components are carbohydrates, lipids, proteins, vitamins, minerals, dietary fibre and water.

2.

Why does the body need carbohydrates?

Carbohydrates provide energy for activities and chemical reactions in the body.

3.

Why does the body need lipids?

Lipids provide energy, form part of cell membranes and help insulate the body.

4.

Why does the body need proteins?

Proteins are needed for growth and repair and are used to make important substances such as enzymes.

5.

Why does the body need vitamins?

Vitamins are needed in small amounts to keep the body healthy and allow important processes to occur.

6.

Why does the body need minerals?

Minerals are needed in small amounts for healthy growth and normal body functions.

7.

Why does the body need dietary fibre?

Dietary fibre helps food move through the digestive system and helps prevent constipation.

8.

Why does the body need water?

Water is needed for chemical reactions, transport of substances and many other processes in the body.

9.

What is meant by a person's energy requirement?

A person's energy requirement is the amount of energy their body needs from food to maintain normal activities and body functions.

10.

Why does the body need energy from food?

The body needs energy for movement, maintaining body temperature, growth, repair and other life processes.

11.

What factors can affect a person's daily energy requirement?

Energy requirements can be affected by age, body size, sex and level of physical activity.

12.

How can energy requirements in a healthy daily diet be calculated?

Energy requirements can be estimated by calculating the energy needed for the person's body functions and activities, using information such as body size, age and activity level.

13.

What is meant by an imbalance in the diet?

An imbalance in the diet occurs when a person's diet contains too much or too little of one or more nutrients or energy.

14.

What is obesity?

Obesity is a condition in which a person has an unhealthy amount of body fat, often caused by taking in more energy than the body uses over time.

15.

What is starvation?

Starvation is a severe lack of food or nutrients that prevents the body from getting enough energy and nutrients.

16.

What is a deficiency disease?

A deficiency disease is a disease caused by not getting enough of a particular nutrient.

17.

How can a lack of a particular nutrient cause a deficiency disease?

If the body does not receive enough of a nutrient it needs, a deficiency can prevent normal body processes and cause disease.

18.

What are the main organs of the human digestive system?

The main organs include the mouth, oesophagus, stomach, small intestine, large intestine, rectum and anus.

19.

What is the function of the mouth in digestion?

The mouth begins digestion by mechanically breaking food into smaller pieces and mixing it with saliva, which contains digestive enzymes.

20.

What is the function of the stomach in digestion?

The stomach stores and churns food and contains acid and enzymes that help digest proteins.

21.

What is the function of the small intestine in digestion?

The small intestine completes much of digestion and absorbs soluble digested nutrients into the blood.

22.

What is the function of the large intestine in digestion?

The large intestine absorbs water from the remaining material and forms faeces.

23.

What is an enzyme?

An enzyme is a biological catalyst that speeds up chemical reactions without being used up.

24.

How do enzymes help digest food?

Digestive enzymes break large, insoluble food molecules into smaller, soluble molecules that can be absorbed into the blood.

25.

What is the importance of bacteria in the human digestive system?

Bacteria in the human digestive system help break down some substances in food and can produce useful substances for the body.

Nutrition and digestion — Plant nutrition

1.

What process do plants use to make carbohydrates?

Plants use photosynthesis to make carbohydrates.

2.

Where in a plant are carbohydrates made by photosynthesis?

Carbohydrates are made mainly in the leaves, inside chloroplasts.

3.

What is needed for photosynthesis to take place?

Photosynthesis needs light energy, carbon dioxide and water.

4.

Why do plants need carbohydrates?

Plants use carbohydrates for energy, growth and making other substances needed by the plant.

5.

How do plant roots obtain water from the soil?

Water enters plant roots from the soil by osmosis.

6.

How do plant roots obtain mineral nutrients from the soil?

Mineral nutrients enter plant roots from the soil, often by active transport.

7.

Why do plants need mineral nutrients?

Plants need mineral nutrients for healthy growth and to make important substances.

8.

Why is water important to plants?

Water is needed for photosynthesis, transport of substances and keeping plant cells firm.

9.

How are roots adapted to absorb water and mineral nutrients?

Roots have many root hair cells, giving them a large surface area for absorbing water and mineral nutrients.

10.

How do plants use the carbohydrates made by photosynthesis?

Plants use carbohydrates for respiration, growth and making substances such as cellulose and starch.

11.

What is the role of leaves in photosynthesis?

Leaves absorb light and carbon dioxide and contain chloroplasts where photosynthesis takes place.

12.

Why are leaves well suited to making carbohydrates by photosynthesis?

Leaves are broad and thin, giving them a large surface area for absorbing light and a short distance for gases to diffuse.

13.

What is the source of the water used by plants for photosynthesis?

The water used in photosynthesis comes from the soil and is absorbed by the roots.

14.

What is the source of the mineral nutrients needed by plants?

Mineral nutrients come from the soil and are absorbed by the plant roots.

15.

Why are mineral nutrients important for healthy plant growth?

Mineral nutrients are needed to make substances required for healthy growth and normal plant functions.

16.

How do roots help plants obtain substances from the soil?

Roots provide a large surface area for absorbing water and mineral nutrients from the soil.

17.

What would happen to a plant if it could not obtain enough water?

Without enough water, a plant may wilt and photosynthesis and growth will be reduced.

18.

What would happen to a plant if it could not obtain enough mineral nutrients?

Without enough mineral nutrients, a plant may grow poorly and develop deficiency symptoms.

19.

Why do plants need both water and mineral nutrients from the soil?

Plants need water for photosynthesis and other processes, while mineral nutrients are needed to make important substances and support growth.

20.

How are water and mineral nutrients transported from roots to the rest of a plant?

Water and mineral nutrients are transported from the roots to other parts of the plant through xylem vessels.

21.

How does photosynthesis provide carbohydrates for plants?

Photosynthesis uses light energy to convert carbon dioxide and water into glucose, which is a carbohydrate.

22.

Why are carbohydrates important to plants?

Carbohydrates provide energy and are used to build materials needed for plant growth and storage.

23.

What is the relationship between leaves, roots and plant nutrition?

Leaves make carbohydrates by photosynthesis, while roots absorb water and mineral nutrients needed by the plant.

24.

How do plants obtain the materials they need for healthy growth?

Plants obtain carbon dioxide from the air, water and mineral nutrients from the soil, and light energy from the Sun.

25.

How do photosynthesis and root absorption help a plant survive?

Photosynthesis provides carbohydrates, while roots supply water and mineral nutrients, allowing the plant to grow, carry out life processes and survive.

Gas exchange systems

1.

What is gas exchange?

Gas exchange is the movement of gases, such as oxygen and carbon dioxide, between an organism and its surroundings.

2.

What is the function of the human gas exchange system?

The human gas exchange system takes oxygen into the body and removes carbon dioxide.

3.

What are the main structures of the human gas exchange system?

The main structures are the nose or mouth, trachea, bronchi, bronchioles and lungs containing alveoli.

4.

What is the function of the trachea?

The trachea carries air into and out of the lungs.

5.

What is the function of the bronchi?

The bronchi are two tubes that carry air from the trachea into each lung.

6.

What is the function of the bronchioles?

The bronchioles are smaller airways that carry air through the lungs to the alveoli.

7.

What is the function of the alveoli?

The alveoli are tiny air sacs where oxygen and carbon dioxide are exchanged between the air and blood.

8.

How are alveoli adapted for efficient gas exchange?

Alveoli have a large surface area, thin walls and a good blood supply, allowing gases to diffuse quickly.

9.

Which gases are exchanged between the alveoli and the blood?

Oxygen moves from the alveoli into the blood, while carbon dioxide moves from the blood into the alveoli.

10.

What is inhalation?

Inhalation is the process of breathing air into the lungs.

11.

What happens to the diaphragm during inhalation?

During inhalation, the diaphragm contracts and flattens.

12.

What happens to the volume of the chest during inhalation?

The volume of the chest increases during inhalation.

13.

What happens to the pressure inside the lungs during inhalation?

The pressure inside the lungs decreases during inhalation.

14.

What is exhalation?

Exhalation is the process of breathing air out of the lungs.

15.

What happens to the diaphragm during exhalation?

During exhalation, the diaphragm relaxes and becomes domed-shaped.

16.

What happens to the volume of the chest during exhalation?

The volume of the chest decreases during exhalation.

17.

What happens to the pressure inside the lungs during exhalation?

The pressure inside the lungs increases during exhalation.

18.

How does a change in pressure cause air to move into and out of the lungs?

Air moves from areas of higher pressure to areas of lower pressure, so changes in lung pressure cause air to enter or leave the lungs.

19.

What is lung volume?

Lung volume is the amount of air contained in the lungs.

20.

How can lung volume be measured?

Lung volume can be measured using a spirometer.

21.

How does exercise affect breathing?

Exercise increases breathing rate and usually increases the depth of breathing because muscles need more oxygen and produce more carbon dioxide.

22.

How can asthma affect the gas exchange system?

Asthma can narrow the airways, making it harder for air to move into and out of the lungs.

23.

How can smoking damage the gas exchange system?

Smoking can damage the lungs and reduce the efficiency of gas exchange.

24.

What are two effects of smoking on the lungs?

Smoking can damage the alveoli and increase the risk of lung diseases such as lung cancer.

25.

What is the role of stomata in gas exchange in plants?

Stomata are tiny openings in plant leaves that allow gases such as carbon dioxide and oxygen to move into and out of the leaf.

Human reproduction

1.

What is reproduction?

Reproduction is the process by which living organisms produce offspring of their own species.

2.

What are the main organs of the male reproductive system?

The main male reproductive organs include the testes, sperm ducts, penis and glands that add fluid to sperm.

3.

What are the main organs of the female reproductive system?

The main female reproductive organs include the ovaries, oviducts, uterus, cervix and vagina.

4.

What is the function of the testes?

The testes produce sperm and the male sex hormone testosterone.

5.

What is the function of the sperm ducts?

The sperm ducts carry sperm from the testes towards the urethra.

6.

What is the function of the penis?

The penis transfers sperm into the female reproductive system during sexual intercourse.

7.

What is the function of the ovaries?

The ovaries produce eggs and female sex hormones.

8.

What is the function of the oviducts?

The oviducts carry eggs from the ovaries towards the uterus and are usually where fertilisation occurs.

9.

What is the function of the uterus?

The uterus is where a fertilised egg develops into a foetus during pregnancy.

10.

What is the function of the vagina?

The vagina is a muscular passage that receives sperm during sexual intercourse and forms the birth canal.

11.

What are gametes?

Gametes are reproductive cells that contain genetic information and can fuse during fertilisation.

12.

What are the male and female gametes in humans?

The male gamete is the sperm cell and the female gamete is the egg cell.

13.

What happens during the menstrual cycle?

During the menstrual cycle, an egg matures and is released from an ovary. The lining of the uterus thickens and is later shed if pregnancy does not occur.

14.

What is fertilisation?

Fertilisation is the fusion of a sperm cell and an egg cell to form a fertilised egg cell.

15.

Where does fertilisation normally occur in humans?

Fertilisation normally occurs in an oviduct.

16.

What is gestation?

Gestation is the period during which a developing baby grows inside the uterus before birth.

17.

Where does the foetus develop during pregnancy?

The foetus develops in the uterus during pregnancy.

18.

What is the function of the placenta?

The placenta allows substances such as oxygen and nutrients to pass from the mother's blood to the foetus and waste substances such as carbon dioxide to pass back.

19.

How can maternal lifestyle affect the developing foetus?

A mother's lifestyle can affect the development and health of the foetus because substances taken into the mother's body can reach the foetus.

20.

How can smoking during pregnancy affect the foetus?

Smoking during pregnancy can reduce the oxygen supply to the foetus and increase the risk of poor growth and other health problems.

21.

How can alcohol consumption during pregnancy affect the foetus?

Alcohol consumption during pregnancy can damage the developing foetus and affect its growth and development.

22.

How does the placenta provide the foetus with substances needed for growth?

The placenta allows useful substances such as oxygen and nutrients to pass from the mother's blood to the foetus.

23.

How does the placenta prevent the mother's and foetus's blood from directly mixing?

The mother's and foetus's blood are kept separate, although substances can move between them across the placenta.

24.

What happens during birth?

During birth, muscles in the uterus contract, the cervix widens and the baby passes through the vagina.

25.

What are the main stages of human reproduction from fertilisation to birth?

The main stages are fertilisation → development of the embryo and foetus in the uterus → birth.

Plant reproduction

1.

What are the main reproductive structures of a flower?

The main reproductive structures of a flower are the anther, filament, stigma, style, ovary and ovules.

2.

What is the function of the anther?

The anther produces and releases pollen grains containing the male reproductive cells.

3.

What is the function of the stigma?

The stigma receives pollen and is often sticky so pollen can attach to it.

4.

What is the function of the ovary?

The ovary contains the ovules and develops into the fruit after fertilisation.

5.

What is the function of the ovule?

The ovule contains the female reproductive cell and develops into a seed after fertilisation.

6.

What is pollination?

Pollination is the transfer of pollen from an anther to a stigma of a flower of the same species.

7.

What is insect pollination?

Insect pollination occurs when insects transfer pollen between flowers.

8.

What is wind pollination?

Wind pollination occurs when pollen is carried from one flower to another by the wind.

9.

What is the difference between insect-pollinated and wind-pollinated flowers?

Insect-pollinated flowers often have bright petals, scent and nectar, while wind-pollinated flowers often have exposed anthers and feathery stigmas.

10.

How are insect-pollinated flowers adapted for pollination?

Insect-pollinated flowers may have brightly coloured petals, scent, nectar and sticky pollen to attract insects and help pollen stick to them.

11.

How are wind-pollinated flowers adapted for pollination?

Wind-pollinated flowers often have exposed anthers, large feathery stigmas and produce large amounts of small, light pollen.

12.

What happens when pollen lands on a suitable stigma?

When pollen lands on a suitable stigma, it can grow a pollen tube down towards an ovule.

13.

What is fertilisation in flowering plants?

Fertilisation in flowering plants is the fusion of the male reproductive cell from pollen with the female reproductive cell in an ovule.

14.

Where does fertilisation take place in a flowering plant?

Fertilisation takes place inside an ovule in the ovary.

15.

What happens to an ovule after fertilisation?

After fertilisation, an ovule develops into a seed.

16.

What happens to the ovary after fertilisation?

After fertilisation, the ovary develops into a fruit.

17.

What is a seed?

A seed contains a young plant embryo and stored food, surrounded by a protective seed coat.

18.

What is a fruit?

A fruit is a structure that develops from the ovary and contains or protects seeds.

19.

Why are seeds dispersed away from the parent plant?

Seeds are dispersed away from the parent plant to reduce competition for resources such as light, water and minerals.

20.

What are some different methods of seed dispersal?

Seeds can be dispersed by wind, animals, water or explosive mechanisms.

21.

How can wind disperse seeds?

Wind can carry lightweight seeds or seeds with structures such as wings or parachutes away from the parent plant.

22.

How can animals disperse seeds?

Animals can disperse seeds by eating fruits and later passing the seeds out, or by carrying seeds attached to their bodies.

23.

How can water disperse seeds?

Water can carry seeds that float from one place to another.

24.

What measurements could be taken in a quantitative investigation of seed dispersal?

Measurements could include the distance travelled by seeds, the number of seeds dispersed and the proportion dispersed by each method.

25.

How can the effectiveness of different seed dispersal mechanisms be compared?

Different mechanisms can be compared by measuring factors such as the distance seeds travel, the number dispersed and how effectively they move away from the parent plant.

Health

1.

What is a drug?

A drug is a substance that changes the way the body works.

2.

What is a recreational drug?

A recreational drug is a drug taken for enjoyment or its effects rather than to treat a medical condition.

3.

What is meant by substance misuse?

Substance misuse means using a substance in a way that can cause harm to a person's health or wellbeing.

4.

What is the difference between a medicinal drug and a recreational drug?

A medicinal drug is used to prevent, diagnose or treat illness, while a recreational drug is generally taken for its effects rather than medical treatment.

5.

How can recreational drugs affect behaviour?

Recreational drugs can change behaviour by affecting mood, alertness, judgement and reactions.

6.

How can recreational drugs affect physical health?

Recreational drugs can harm physical health and may damage organs or increase the risk of illness and injury.

7.

How can recreational drugs affect the brain?

Recreational drugs can affect the brain by changing the activity of nerve cells and altering mood, thinking and behaviour.

8.

How can recreational drugs affect the nervous system?

Recreational drugs can change how the nervous system sends and processes signals around the body.

9.

How can recreational drugs affect coordination?

Some recreational drugs can reduce coordination by affecting the brain and nervous system.

10.

How can recreational drugs affect a person's ability to make decisions?

Recreational drugs can affect decision-making by changing judgement and how a person responds to risks.

11.

How can recreational drugs affect heart rate?

Some recreational drugs can increase or decrease heart rate.

12.

How can recreational drugs affect breathing?

Some recreational drugs can change breathing rate or make breathing slower and less effective.

13.

How can recreational drugs affect normal body functions?

Recreational drugs can interfere with normal body functions by changing how the brain, nervous system and organs work.

14.

What is drug dependence?

Drug dependence is when a person becomes reliant on a drug and finds it difficult to stop taking it.

15.

How can repeated use of some recreational drugs lead to dependence?

Repeated use of some drugs can cause changes in the brain that lead to dependence and a strong desire to keep using the drug.

16.

Why can drug dependence make it difficult to stop using a drug?

Dependence can make stopping difficult because a person may experience strong cravings or withdrawal symptoms.

17.

Why can taking too much of a recreational drug be dangerous?

Taking too much of a recreational drug can cause poisoning, serious harm or even death.

18.

How can recreational drugs affect short-term behaviour?

Recreational drugs can cause short-term changes such as altered mood, reduced coordination, poor judgement or changes in alertness.

19.

How can recreational drugs affect long-term health?

Long-term misuse can lead to dependence, damage to organs and an increased risk of serious diseases.

20.

How can substance misuse affect everyday life?

Substance misuse can affect school or work, relationships, finances and a person's physical and mental wellbeing.

21.

How can recreational drugs affect the senses?

Some recreational drugs can alter the senses, causing changes in how a person sees, hears or feels things.

22.

How can recreational drugs affect movement and coordination?

Recreational drugs can affect movement and coordination by changing the activity of the brain and nervous system.

23.

How can recreational drugs affect judgement?

Recreational drugs can affect judgement, making a person more likely to take risks or make unsafe decisions.

24.

Why can different recreational drugs have different effects on the body?

Different drugs contain different chemicals that act on different parts of the brain and body, so their effects can differ.

25.

Why is it important to understand the effects and risks of recreational drugs?

Understanding the effects and risks of recreational drugs helps people make informed decisions and reduce the risk of harm.

Photosynthesis

1.

What is photosynthesis?

Photosynthesis is the process by which plants, algae and some microorganisms use light energy to make organic molecules from carbon dioxide and water.

2.

What are the reactants needed for photosynthesis?

The reactants are carbon dioxide and water.

3.

What are the products of photosynthesis?

The products are glucose and oxygen.

4.

What is the word summary for photosynthesis?

Carbon dioxide + water → glucose + oxygen.

5.

Where does the energy for photosynthesis come from?

The energy comes from light, mainly from the Sun.

6.

Which organisms carry out photosynthesis?

Plants, algae and some microorganisms carry out photosynthesis.

7.

How do plants use sunlight during photosynthesis?

Plants absorb light energy using chlorophyll in their chloroplasts.

8.

What are organic molecules?

Organic molecules are carbon-containing molecules made by living organisms, such as glucose.

9.

Why are organic molecules made during photosynthesis important to living organisms?

Organic molecules provide materials and stored energy needed for growth and life processes.

10.

How does photosynthesis provide an energy store for plants?

Photosynthesis converts light energy into chemical energy stored in glucose.

11.

Why do animals depend on photosynthetic organisms for energy?

Animals depend on photosynthetic organisms because they obtain energy by eating plants, algae or organisms that depend on them.

12.

Why do almost all living organisms on Earth depend on photosynthesis?

Almost all living organisms depend on photosynthesis because it provides the organic molecules and energy that form the basis of most food chains.

13.

How does photosynthesis help maintain oxygen levels in the atmosphere?

Photosynthesis releases oxygen into the atmosphere.

14.

How does photosynthesis affect carbon dioxide levels in the atmosphere?

Photosynthesis removes carbon dioxide from the atmosphere.

15.

Why are plants and algae important for the balance of gases in the atmosphere?

Plants and algae help maintain the balance of oxygen and carbon dioxide in the atmosphere.

16.

What is the function of a leaf in photosynthesis?

A leaf is the main organ where photosynthesis takes place.

17.

How are leaves adapted to absorb sunlight?

Leaves are broad and contain many chloroplasts, allowing them to absorb large amounts of light.

18.

How are leaves adapted to allow carbon dioxide to enter?

Stomata allow carbon dioxide to enter the leaf.

19.

How are leaves adapted to transport water to photosynthesising cells?

Water is transported to photosynthesising cells through the plant's transport tissues.

20.

Why are most leaves broad and thin?

Most leaves are broad to provide a large surface area for absorbing light and thin to provide a short distance for gases to diffuse.

21.

Why do leaves contain chlorophyll?

Chlorophyll absorbs light energy needed for photosynthesis.

22.

How are chloroplasts adapted for photosynthesis?

Chloroplasts contain chlorophyll and provide the structures where photosynthesis takes place.

23.

How does the arrangement of cells inside a leaf help photosynthesis?

The arrangement of cells allows light to reach photosynthesising cells while providing spaces for carbon dioxide to move through the leaf.

24.

How do stomata help a leaf carry out photosynthesis?

Stomata allow carbon dioxide to enter and oxygen to leave the leaf.

25.

How do the adaptations of leaves make photosynthesis more efficient?

Broad, thin leaves, chloroplasts containing chlorophyll, suitable cell arrangements and stomata all help maximise the efficiency of photosynthesis.

Cellular respiration

1.

What is cellular respiration?

Cellular respiration is the chemical process in which cells break down organic molecules to release energy.

2.

Why is cellular respiration needed by living organisms?

Cellular respiration provides energy needed for life processes such as movement, growth and keeping the body warm.

3.

What happens to organic molecules during cellular respiration?

Organic molecules are broken down during cellular respiration, releasing energy.

4.

How does cellular respiration provide energy for life processes?

The released energy is used to power life processes.

5.

What is aerobic respiration?

Aerobic respiration is respiration that uses oxygen.

6.

What are the reactants of aerobic respiration?

The reactants are glucose and oxygen.

7.

What are the products of aerobic respiration?

The products are carbon dioxide, water and energy.

8.

What is the word summary for aerobic respiration?

Glucose + oxygen → carbon dioxide + water + energy.

9.

What is anaerobic respiration?

Anaerobic respiration is respiration that releases energy without using oxygen.

10.

When does anaerobic respiration occur in humans?

Anaerobic respiration occurs in human muscles when there is not enough oxygen for aerobic respiration, such as during vigorous exercise.

11.

What are the products of anaerobic respiration in humans?

The products of anaerobic respiration in humans are lactic acid and energy.

12.

What is the word summary for anaerobic respiration in humans?

Glucose → lactic acid + energy.

13.

What is fermentation?

Fermentation is anaerobic respiration carried out by microorganisms such as yeast.

14.

Which types of organisms can carry out fermentation?

Microorganisms such as yeast and some bacteria can carry out fermentation.

15.

What are the products of anaerobic respiration in microorganisms?

In yeast, the products are ethanol, carbon dioxide and energy.

16.

How does anaerobic respiration in microorganisms differ from anaerobic respiration in humans?

Humans produce lactic acid during anaerobic respiration, whereas yeast produces ethanol and carbon dioxide.

17.

How do the reactants of aerobic and anaerobic respiration differ?

Aerobic respiration requires oxygen, while anaerobic respiration does not.

18.

How do the products of aerobic and anaerobic respiration differ?

Aerobic respiration produces carbon dioxide and water, while anaerobic respiration produces different products depending on the organism.

19.

Why does anaerobic respiration provide less energy than aerobic respiration?

Anaerobic respiration releases less energy because glucose is not completely broken down.

20.

What happens to muscles when there is not enough oxygen for aerobic respiration?

Muscles produce lactic acid when there is not enough oxygen for aerobic respiration.

21.

What causes the need for anaerobic respiration during vigorous exercise?

Vigorous exercise increases the muscles' demand for energy faster than oxygen can be supplied.

22.

How can anaerobic respiration affect an organism?

Anaerobic respiration allows cells to continue releasing some energy but can lead to the build-up of lactic acid in muscles.

23.

How does aerobic respiration differ from anaerobic respiration in terms of oxygen?

Aerobic respiration requires oxygen, whereas anaerobic respiration occurs without oxygen.

24.

How does anaerobic respiration allow cells to release energy when oxygen is limited?

Anaerobic respiration allows cells to release some energy from organic molecules when oxygen is limited.

25.

Why is respiration essential for all living organisms?

Respiration is essential because cells need the released energy to carry out life processes.

Relationships in an ecosystem

1.

What is an ecosystem?

An ecosystem is a community of organisms interacting with each other and with their physical environment.

2.

What is meant by the interdependence of organisms?

Interdependence means organisms depend on other organisms for things such as food, pollination, shelter or reproduction.

3.

Why do organisms in an ecosystem depend on one another?

Organisms depend on one another for resources, food, reproduction and survival.

4.

What is a food web?

A food web shows how several food chains are linked together in an ecosystem.

5.

What do arrows in a food web represent?

Arrows in a food web show the direction of energy transfer from the organism being eaten to the organism that eats it.

6.

How can a change in one population affect other populations in a food web?

A change in one population can cause the populations of other organisms in the food web to increase or decrease.

7.

Why are insects important to many flowering plants?

Insects pollinate many flowering plants, allowing them to reproduce and produce seeds and fruits.

8.

What is insect pollination?

Insect pollination is the transfer of pollen from one flower to another by insects.

9.

How do insect-pollinated crops depend on insects?

Insect-pollinated crops depend on insects to transfer pollen between flowers so that fertilisation can occur.

10.

Why is insect pollination important for human food security?

Insect pollination is important for food security because many food crops depend on insect pollinators to produce fruits and seeds.

11.

What could happen to food production if insect pollinators declined?

A decline in insect pollinators could reduce the pollination and production of many crops.

12.

How can organisms affect their environment?

Organisms can change their environment through activities such as feeding, burrowing, growing and producing waste.

13.

How can an organism's environment affect its survival?

An organism's environment provides conditions and resources that affect its ability to survive and reproduce.

14.

What is meant by environmental conditions?

Environmental conditions are the physical and chemical conditions surrounding organisms, such as temperature, light and water availability.

15.

How can changes in environmental conditions affect populations?

Changes in environmental conditions can cause population sizes and distributions to change.

16.

What are toxic materials?

Toxic materials are substances that can harm living organisms.

17.

How can toxic materials enter an ecosystem?

Toxic materials can enter ecosystems through pollution, waste, pesticides and other human activities.

18.

How can toxic materials accumulate in organisms?

Toxic materials can accumulate when organisms take them in faster than they can remove them.

19.

Why can toxic materials become more harmful as they pass through a food web?

Toxic materials can become more concentrated at higher levels of a food web because predators consume many contaminated organisms.

20.

How can toxic materials affect organisms in an ecosystem?

Toxic materials can damage organisms, reduce their ability to reproduce and may cause illness or death.

21.

How can the removal of one species affect an ecosystem?

Removing one species can disrupt food webs and affect the populations of other species that depend on it.

22.

How can changes in food availability affect organisms in an ecosystem?

Changes in food availability can cause populations that rely on that food to increase or decrease.

23.

Why can changes in one part of an ecosystem affect organisms elsewhere in the ecosystem?

Organisms are interconnected, so changes affecting one population can spread through feeding relationships and other interactions.

24.

How can human activities such as pollution and habitat destruction disrupt relationships between organisms in an ecosystem?

Human activities such as pollution and habitat destruction can reduce populations, remove food sources or destroy habitats, disrupting relationships between organisms.

25.

Why is understanding interdependence important when managing ecosystems?

Understanding interdependence helps people predict the effects of environmental changes and manage ecosystems more effectively.

Inheritance, chromosomes, DNA and genes

1.

What is heredity?

Heredity is the passing of genetic information and characteristics from parents to their offspring.

2.

How is genetic information passed from one generation to the next?

Genetic information is passed from parents to offspring through genes carried in reproductive cells.

3.

What is a chromosome?

A chromosome is a long, coiled molecule of DNA containing many genes.

4.

Where are chromosomes found in cells?

Chromosomes are found in the nucleus of cells.

5.

What is DNA?

DNA is the molecule that carries genetic information.

6.

Where is DNA found in a cell?

DNA is mainly found in the nucleus of a cell.

7.

What is a gene?

A gene is a section of DNA that contains genetic information.

8.

How are genes related to DNA?

Genes are sections of DNA that provide information for characteristics.

9.

How are genes and chromosomes related?

Genes are sections of DNA found along chromosomes.

10.

How does genetic information influence the characteristics of an organism?

Genetic information influences characteristics by providing instructions that affect how an organism develops and functions.

11.

What is a species?

A species is a group of organisms that can reproduce with one another to produce fertile offspring.

12.

What does it mean for two organisms to belong to different species?

Organisms belong to different species when they cannot normally reproduce with each other to produce fertile offspring.

13.

What is variation?

Variation is the difference in characteristics between individuals of the same species.

14.

What is continuous variation?

Continuous variation is variation that can have any value within a range, such as height.

15.

What is discontinuous variation?

Discontinuous variation has distinct categories with no intermediate values, such as blood group.

16.

How can continuous variation be measured?

Continuous variation can be measured using numerical measurements such as height, mass or length.

17.

How can variation between individuals be represented using a graph?

Variation can be represented using graphs such as histograms or scatter graphs, depending on the type of data.

18.

Why do individuals of the same species vary?

Individuals of the same species vary because they inherit different genetic information and may experience different environmental conditions.

19.

Why can some organisms compete more successfully than others?

Some organisms have characteristics that make them better suited to their environment, allowing them to survive and reproduce more successfully.

20.

How can variation lead to natural selection?

Variation can cause some individuals to have advantageous characteristics, which may allow them to survive and reproduce more successfully.

21.

How can changes in the environment make organisms less well adapted?

If the environment changes, characteristics that were previously advantageous may become less useful or disadvantageous.

22.

How can poor adaptation to environmental change lead to extinction?

Poor adaptation may reduce survival and reproduction, causing a population to decrease and potentially become extinct.

23.

What is biodiversity?

Biodiversity is the variety of different living organisms in an area or on Earth.

24.

Why is maintaining biodiversity important?

Maintaining biodiversity helps ecosystems remain healthy and provides resources such as food, medicines and genetic material.

25.

What are gene banks, and how can they help preserve hereditary material?

Gene banks store genetic material such as seeds, sperm or DNA and can help preserve genetic diversity for future use.

Biology

Structure and function of living organisms