biology review chapter 15

which one in the following is not the effect of human overpopulation?

• the demand of food consumption increase

• the demand to use fuel as the sources of energy increase

• the rate of environmental pollution decrease

• the natural habitat for other living organisms decrease

controlling the soil structure is important to improve the aeration and drainage of the soil. in which way a farmer can control the soil structure?

• add more fertiliser to the soil

• plough the field and add manure to the soil

• add lime (calcium salts) to the soil

• make a glasshouse

which one of the following is the benefit of using glasshouse or polytunnels?

• to keep the temperature warm during the colder season

• to block the excessive sunlight that can raise the rate of transpiration during the day

• to reduce the amount of required fertiliser

• to maintain the amount of greenhouse gases around the plants

what is the importance of nitrogen for the crops?

• to help the plants make sugar

• to help the plants make proteins and other compounds for growth

• to help the plants absorb more water from the soil

• to help the plants absorb more carbon dioxide

adding farmyard manure returns some nitrogen to the soil. but, as farmyard manure is made from livestock faeces and indigestible fodder, it can only replace a portion of the lost nitrogen. what can a farmer do to overcome this situation?

• keep the plants in a polytunnel

• keep ploughing the soil regularly

• apply pesticides

• apply inorganic fertilisers

some farmers do the crop rotation in their farm. they grow different crops each year as shown in the following cycle. what is the purpose of crop rotation in a farm?

• to keep the soil moist

• to add up nitrogen content in the soil

• to speed up the decomposition process

• to break the pest cycle

the following diagram shows the concentration of DDT in each organism in a food chain. the diagrams shows that DDT..

• accumulates in the tissues of organisms and cause biomagnification

• are safe to be used in the ecosystem

• gives energy to the living organisms in the food chain

• is accumulated the most in the producers

biological control is known to be a better option to control the amount of pest rather tha using a toxic chemical. the population of aphids in citrust plants is increase as shown in the following picture. how can a farmer perform bioloigcal control to overcome the situation?

• spray some insecticide

• release the natural predators of aphids, like ladybirds

• release the herbivores such as moth to eat up the infected parts of plants

• add more fertiliser tot he soil to accelerate the plant's growth

fish farming is a good method to increase the fish production for human consumption. in a fish farm, the optimal condition for the fish growth is carefully controlled. but the controlling procedures also can lead to some problems. which of the following is not a problem caused by a fish farm?

• antibiotic resistance

• contamination of the water around the fish farm

• endanger the 'wild' fish stocks

• lower the potential of disease to spread

which one of the following is the correct definition for pollution?

• the situation where large amounts of nutrients enter a body of water, such as a river, lake or even the sea

• the warming of earth's surface and the air above it

• the contamination of the environment by harmful substances that are produced by the activities of humans

• the destruction of habitats and reduced biodiversity