Year 9 Science Revision Flashcards

Flashcards for Year 9 Science Revision based on lecture notes.

Which organelle is responsible for producing energy in cells?

Mitochondria

Which of these is not found in a bacterial cell?

Mitochondria

What is the word equation for aerobic respiration?

Glucose + Oxygen -> Carbon Dioxide + Water

Which energy store increases when an object is lifted?

Gravitational potential

What is the charge of a neutron?

No charge (neutral)

What is the atomic number of an element?

Number of protons

Which group in the periodic table contains the noble gases?

Group 0

What type of bond is formed between a metal and a non-metal?

Ionic

Which of these processes uses energy from sunlight?

Photosynthesis

What is the symbol for sodium?

Na

Which structure controls what enters and leaves a cell?

Cell membrane

What is the function of ribosomes?

Make proteins

Which organelle contains genetic material?

Nucleus

In which part of the cell does respiration take place?

Mitochondria

Which one is a eukaryotic cell?

Yeast

Which element has the atomic number 6?

Carbon

Which subatomic particle has a negative charge?

Electron

What happens to electrons in ionic bonding?

Lost or gained (transferred)

Metals tend to ___ electrons in bonding.

Lose

What is the group number of halogens?

Group 7

Which process releases energy in cells?

Respiration

Which one is a renewable energy source?

Solar

What is the unit of energy?

Joule

Which is not a fossil fuel?

Biomass

Which bond is found in water molecules?

Covalent

Name two sub-cellular structures found in plant cells but not in animal cells.

Chloroplast and Cell wall

State the function of the cell membrane.

It controls what enters and leaves the cell.

What is meant by anaerobic respiration?

Respiration without oxygen.

Why does heart rate increase during exercise?

To pump more oxygen to muscles and remove carbon dioxide.

What is meant by 'conservation of energy'?

Energy cannot be made or destroyed, only transferred.

A ball is thrown upwards. Describe the energy transfers that take place.

Kinetic -> Gravitational potential as it goes up, then back to kinetic as it falls.

What is the difference between atomic number and mass number?

Atomic number = protons; Mass number = protons + neutrons.

An atom of magnesium has 12 protons and 12 neutrons. What is its mass number?

24

Write down the electronic structure of a fluorine atom.

2, 7

Explain how ions are formed in ionic bonding.

Atoms lose or gain electrons to get full outer shells. This forms ions.

Describe what happens when a Group 1 metal reacts with water.

It fizzes, moves, and makes hydrogen gas and an alkaline solution.

Describe one function of the mitochondria.

They release energy from food by respiration.

State one difference between plant and animal cells.

Plant cells have a cell wall, animal cells do not.

What is meant by the term 'cell differentiation'?

When a cell becomes specialised to do a specific job.

What is active transport? Give an example.

Movement of substances using energy, like minerals into root hair cells.

Describe how root hair cells are adapted to absorb water.

They have a large surface area and thin walls.

Give one advantage and one disadvantage of anaerobic respiration.

Advantage: no oxygen needed. Disadvantage: less energy made.

What are enzymes? What is their role in digestion?

Enzymes are proteins that speed up digestion by breaking down food.

Name three parts of a bacterial cell.

Cell wall, cell membrane, plasmid.

Explain what happens during mitosis.

The cell divides to make two identical cells for growth or repair.

Compare aerobic and anaerobic respiration.

Aerobic uses oxygen and makes more energy; anaerobic does not use oxygen and makes less.

What is meant by energy efficiency?

How much energy is usefully transferred.

A bulb uses 200 J of energy. 50 J is wasted as heat. What is its efficiency?

75% efficiency.

Describe the energy changes when a pendulum swings.

Top: gravitational potential -> bottom: kinetic -> back again.

Explain how fossil fuels are formed.

From dead plants and animals buried for millions of years.

State one reason to use renewable energy sources.

They don’t run out.

Describe the structure of an atom.

Nucleus with protons and neutrons; electrons move in shells.

What are isotopes? Give an example.

Same element with different number of neutrons. E.g. Carbon-12 and Carbon-14.

Explain the difference between a period and a group in the periodic table.

Period = row, Group = column with similar properties.

What happens to electrons in a chlorine atom when it becomes an ion?

It gains 1 electron.

Explain how sodium and chlorine form an ionic bond.

Sodium gives 1 electron to chlorine. They become oppositely charged ions that attract.

Describe the properties of ionic compounds.

High melting points and conduct electricity when dissolved.

What are the limitations of the particle model?

It doesn’t show forces or movement between particles.

State the law of conservation of mass.

Mass stays the same in chemical reactions.

What is the role of chloroplasts in a leaf?

They carry out photosynthesis.

Draw and label a plant cell. Describe the function of each part.

Nucleus (controls), Chloroplast (photosynthesis), Vacuole (storage), Cell wall (support), Membrane (controls entry/exit).

Explain how a leaf is adapted for efficient photosynthesis.

Large surface area, chloroplasts, thin, veins, stomata for gas exchange.

Explain the differences between eukaryotic and prokaryotic cells.

Eukaryotic: nucleus, big. Prokaryotic: no nucleus, small. E.g. bacteria.

A student investigates the effect of light on photosynthesis. Describe the method and expected results.

Use pondweed under different lights, count bubbles. More light = faster rate.

Explain how enzymes work and how pH and temperature affect enzyme activity.

Enzymes speed up reactions. Too hot or wrong pH = they stop working.

Describe how electricity is generated in a coal power station.

Coal burns -> heats water -> steam -> turns turbine -> generates electricity.

Explain the importance of diffusion, osmosis, and active transport in living organisms.

They move substances like gases, water, and nutrients in and out of cells.

Compare the structure and function of arteries, veins, and capillaries.

Arteries = thick, high pressure. Veins = valves, low pressure. Capillaries = thin for exchange.

Explain how atoms form ions and how ionic compounds are formed.

Atoms gain/lose electrons to form ions. Opposites attract to form compounds.

Describe how Mendeleev arranged the periodic table and why this was important.

He arranged by mass and properties, left gaps for future elements.

Compare and contrast ionic and covalent bonding, giving examples.

Ionic = transfer of electrons (e.g. NaCl). Covalent = share electrons (e.g. H2O).

Explain how stem cells can be used in medicine. Discuss benefits and risks.

They replace damaged cells. Can cure diseases but may cause tumours or raise ethical issues.