ecosystems

Question 1

what is intraspecific competition?

Answer 1

when organisms within the same species compete with each other for the same resources

Question 2

what is interspecific competition?

Answer 2

when organisms of different species compete with each other for the same resources

Question 3

What is allopatric speciation?

Answer 3

when a physical barrier divides a population of a species

species become reproductively isolated

Question 4

what is sympatric speciation?

Answer 4

speciation caused by mutations within a population living in the same area

mutation means individuals who have the mutation can’t breed with members of the population who don’t have the mutation

Question 5

Explain how farming practices increase the productivity of agricultural crops

Answer 5

• Fertilisers
• Role of named nutrient or element e.g. nitrate / nitrogen for proteins
• Selective breeding / genetic modification (of crops);
• Ploughing / aeration allows nitrification / decreases denitrification
• Benefit of crop rotation in terms of soil nutrients

Question 6

when is the Hardy-Weinberg principle valid?

Answer 6

• large population with no immigration, emigration, mutation or natural selection
• random mating - all possible genotypes can breed with all others

Question 7

definition of genetic drift

Answer 7

change in frequencies of an allele in a gene pool in a population purely due to chance