Biology

Question 1

What are the two types of diseases?

Answer 1

Infectious and non-infectious.

Question 2

What is the difference between the two types of diseases?

Answer 2

Infectious diseases are caused by a pathogen so they can be transmitted while non-infectious diseases are caused by other factors including; genetics, diet and environment.

Question 3

What is a contagious disease?

Answer 3

A contagious disease can be transmitted through either direct contact or microbes travelling through the air.

Question 4

What does each line of defence do in the immune system?

Answer 4

The first line includes physical and chemical barriers such as; stomach acid, mucus and skin which are used to block the pathogen or kill them with enzymes. The second line includes white blood cells which rush to where the pathogens are to kill it through phagocytosis. The third line of defence features the t cells which recognise the pathogen and the b cells that produce antibodies to counteract it.

Question 5

How do plants obtain nitrogen?

Answer 5

Lightning converts atmospheric nitrogen into nitrate which is dropped as water droplets that go into the soil where the roots absorb it.

Question 6

What do nitrifying bacteria do?

Answer 6

Nitrifying bacteria convert nitrogen to nitrates so that plants can absorb them.

Question 7

What do denitrifying bacteria do?

Answer 7

Convert nitrates into nitrogen.

Question 8

How is nitrogen cycled through the ecosystem?

Answer 8

Plants absorb nitrates, animals eat plants and then produce faeces which is made into ammonia.

Question 9

What can decaying organic matter make?

Answer 9

Can be made into ammonia with decomposers which can be denitrified into nitrogen.

Question 10

How do humans interact with abiotic components?

Answer 10

Humans breathe oxygen and drink water.

Question 11

Name the different types of interactions between interdependent organisms.

Answer 11

Predation, mutualism, competition, commensalism and parasitism.

Question 12

How does matter recycle?

Answer 12

Cycles are the way matter recycles.

Question 13

What is ammonia?

Answer 13

Ammonia is nitrogen found in faeces or urine that has the chemical formula. NH3

Question 14

What are the processes in the water cycle?

Answer 14

Evaporation, transpiration, condensation, precipitation and accumulation.

Question 15

What is transpiration?

Answer 15

Plants exhale water through the stomata.

Question 16

What does a food web represent?

Answer 16

The flow of food energy in an ecosystem.

Question 17

What is homeostasis?

Answer 17

The process of some multicellular organisms adapting to changes in their environment to stay in a stable condition.

Question 18

How does the respiratory system and circulatory system work together?

Answer 18

Body systems require the assistance of others for the organism to function. For example, the respiratory system oxygenates the blood which is pumped to the rest of the body by the heart.

Question 19

How does the nervous system respond to stimuli?

Answer 19

Receptors recognise a change in environment or in the body and will send an electrical impulse to the sensory neuron which sends a message to the central nervous system which operates a response through the effectors.

Question 20

How does the nervous and endocrine system work together?

Answer 20

The endocrine system will notify the nervous system there is a shortage of a chemical and the nervous system will activate the gland to release this chemical.