Plants
This part of a flower develops into a fruit after fertilisation.
ovary
This organ removes carbon dioxide and water vapour from the body.
Lungs
Animals that eat both plants and animals are called these.
omnivores
What is a liquid?
This state of matter has a fixed volume but no fixed shape.
A child runs after eating lunch. Explain why breathing and heart rate increase.
The muscles need more oxygen and glucose for respiration to release more energy. The heart pumps faster to deliver oxygen, and breathing increases to take in more oxygen and remove carbon dioxide.
What is pollination?
The transfer of pollen from the anther to the stigma.
This system transports oxygen and nutrients around the body.
circulatory system
A pesticide kills many insects in a forest. Predict two effects this could have on the ecosystem.
A bottle filled with air is squeezed. Explain why the bottle changes shape.
Air is a gas and can be compressed because its particles are far apart.
A sealed plastic bag is placed over a leafy branch. After several hours, water droplets appear inside the bag. Explain why this happens.
Water vapour is lost from the leaves by transpiration. The water vapour condenses on the cooler inner surface of the bag to form droplets.
A plant is kept in a dark cupboard for one week. Predict what happens and explain why.
The plant becomes yellow and weak because it cannot carry out photosynthesis without light to make food.
A cactus has thick stems instead of large leaves. Explain how this helps it survive.
The thick stem stores water, and having small or no leaves reduces water loss through transpiration.
A rabbit population suddenly decreases in a grassland. Predict one effect on the food web.
Predators may decrease because they have less food, while grass may increase because fewer rabbits are eating it.
Water exists in these three states. Name each state and give one example each.
1. Solid - Ice
2. Liquid - Water
3. Gas - Air
Two identical toy cars roll down different ramps. One ramp is steeper. Predict which car travels faster and explain why.
The car on the steeper ramp travels faster because gravity causes it to accelerate more down the slope.
Name the two adaptations that plants with wind-pollinated flowers usually have.
1)small dull petals
2)large feathery stigmas
Why is it important for humans to have both red blood cells and white blood cells?
Red blood cells transport oxygen around the body, while white blood cells defend the body against germs and infections.
What are the four basic need a habitat provides organisms with?
food, water, shelter and space
A metal spoon and a wooden spoon are left in hot soup. Why does the metal spoon become hotter?
Metal is a good conductor of heat, while wood is a poor conductor (insulator).
A metal ruler and a plastic ruler are left under the hot sun for the same amount of time. A student says the metal ruler feels hotter because it absorbs more heat. Is the student correct? Explain.
No. Both rulers absorb heat, but metal is a much better conductor of heat than plastic. It transfers heat to the hand more quickly, so it feels hotter.
A farmer notices that crop growth has slowed even though the plants receive enough sunlight and water. Suggest two possible scientific reasons.
A student eats a sandwich. Describe the journey of the food from the mouth until the nutrients enter the bloodstream.
A species of birds has different beak shapes. One group has long, thin beaks, while another has short, strong beaks. Explain how these different beak shapes help the birds survive.
Different beak shapes are adaptations to different food sources. Long, thin beaks are useful for reaching insects or nectar, while short, strong beaks are useful for cracking seeds. This helps the birds obtain food and survive in their habitats.
A cold can of soft drink is taken out of a refrigerator. After a few minutes, water droplets appear on the outside of the can. A student says the water come from the inside of the can. Is he correct? Explain.
No, the water does not come from inside the can. Water vapour in the surrounding air cools when it touches the cold surface and condenses into liquid water.
A farmer covers the soil around his plants with mulch (a layer of material applied over the soil surface). Explain two reasons why this helps the plants grow better.