Unit 3 Flashcards
What is sampling?
Counting the organisms in a small area then multiplying that number up to estimate how many are in the larger area being studied.
What can be done to increase the amount of food produced from a fixed amount of land?
Use fertilisers, genetically modified crops and pesticides.
This is called intensive farming.
What is intraspecific competition
When individuals of the same species require the same resources.
Why do animals need nitrogen-containing compounds?
To make proteins.
How do animals get nitrogen-containing compounds?
By eating plants and animals?
How do nitrates get into the soil?
From fertilisers or action of bacteria
Describe natural selection
If there are more offspring than the environment can sustain the only those well adapted will survive to reproduce. This means favourable alleles are passed on and less favourable ones die out.
What is a habitat?
A place where things live.
Are mutations always bad?
No, sometimes they have no effect, sometimes they can be advantageous but sometimes they can be bad.
What two types of pyramids are used when studying food chains?
Pyramid of numbers
pyramid of energy
What is a species?
A group of biologically similar organisms that can reproduce t give fertile offspring
What do pesticides do?
Kill living things.
