Human Bio Unit 4 Ecology and Environment Chp. 2: Human influences on the environment

OBJQ + FAQ

What is a greenhouse and its benefits?

-A greenhouse can be heated to raise the temperature if the outside temperature is too low. 

-If heaters use fossil fuels such as gas, they produce carbon dioxide and water vapour, and carbon dioxide is a raw material of photosynthesis. Water vapour moistens the atmosphere, which reduces water loss by transpiration.

What is organic and inorganic?

• Organic—Carbon-containing (naturally made) except carbon dioxide EXAMPLE: Glucose

• Inorganic—Man-made

What are organic and inorganic fertilisers?

• Organic fertilisers—made from faeces of farm animals mixed with straw. 

• Inorganic fertilisers—Formulated to provide a specific amount of minerals according to manufacturers' instructions

OBJQ

What are the advantages and disadvantages of organic and inorganic fertilisers?

Organic fertilisers' benefits	Inorganic fertilisers’ benefits
-Less pollution	- Replace all minerals after mineral ions
-Improve soil structure
Organic fertilisers’ disadvantages	Inorganic fertilisers’ disadvantages
-Can’t replace all minerals	-Pollution
-Can only replace a small portion of nutrients	-Doesn’t improve soil structure

What is another way to replace nitrate in soil?

By legume crops

OBJR 

What is a ‘pest’, and what are its effects on crops?

• Pests are organisms that reduce the yield of crop plants or stock

Pests can harm in 2 ways 

• Lowering the amount by reducing growth

• Affecting the appearance or quality of the crop, making it unsuitable for sale.

OBJQ

What are 2 ways of pest control?

Biological control 

-Release the predator of that pest to kill them.

Chemical control 

-Herbicides (plant pests)

-insecticides (kill insects)

-Fungicides (kill fungi)

- Molluscicides (kill snails, slugs)

OBJQ

What are the problems of using pesticides?

-Pests may develop resistance to chemicals through natural selection

-Environmental damage (eutrophication) 

-Kill useful organisms

-Slow to decompose (persistent) 

-Build up in tissues of organisms (bioaccumulation) 

-Become concentrated along food chain (biomagnification)