What happens in the stomach?
Food is mixed with digestive juices and acid like HCl and Protease enzyme.
What do plants need nitrates for?
Healthy growth,
Why do veins have valves but arteries do not?
wide lumen , thin muscular walls
Where in a leaf is the palisade layer?
Near the top
What are Villi?
Small finger-like projections on the inside of the small intestine which give it a bigger surface area.
Red kites are a type of bird found in England. Some people say that red kites were once extinct in England. Explain why this is the wrong use of the word extinction.
extinction means all members of a species are gone forever. Red kites still existed in other places, so they were only locally extinct, not globally extinct.
What protects the brain in the skeletal system?
Skulls
Why do most food chains only have 4 or 5 links?
There is not usually enough energy left at the end to support another organism.
inct. Suggest what must happen to cause species such as dinosaurs to become extinct.
A species becomes extinct when all its members die and none are left to reproduce. This can happen due to causes like climate change, habitat loss, disease, lac
Explain why respiration in living organisms is so important.
Respiration is important because it releases energy from food, which living organisms need for growth, movement, repair, and other life processes.
What is the difference between voluntary and involuntary muscles?
Voluntary muscles are muscles you can control consciously, like your arm muscles. Involuntary muscles work automatically without you thinking, like your heart a
Give 3 health conditions caused by smoking.
Lung cancer, heart attacks, Chronic bronchitis
What would happen to the population of predators if the population of prey dropped?
It would drop (unless they found something else to eat).