C4

Question 1

open system (2)

Answer 1

where energy and matter can leave

ecosystem

Question 2

closed system (2)

Answer 2

energy is exchanged outside but matter is not

earth

Question 3

Detritivores

Answer 3

oprganism that digests dead material internally

Question 5

Reasons for energy losses in food chains (5)

Answer 5

incomplete consumption - does not consume all parts of the organism

inefficient digestion - cannot absorb all energy in digestion (waste)

inefficient energy conversion and storage - not all energy converted to chemical energy

used in metabolic processes - energy used in metabolic processes (respiration, movement, growth)

heat dissipation - energy dissipates as heat

Question 6

Define primary production (2)

Answer 6

rate at which producers accumulate carbon compounds in their biomass

measured in mass per unit area per unit time

Question 7

Define gross primary productivity

Answer 7

total amount of energy captured as biomass as primary producers

Question 8

Define net primary productivity (2)

Answer 8

energy available to primary consumers

NPP = GPP - R

Question 9

Define secondary production

Answer 9

rate at which consumers accumulate biomass

Question 10

Overproduction in natural selection

Answer 10

populations must produce more offspring than can survive in the ecosystem

Question 11

Define gene pool

Answer 11

all genes and different allleles in an interbreeding population

Question 12

Define evolution

Answer 12

change in gene frequency in a population’s gene pool over time

Question 13

Types of natural selection (3)

Answer 13

directional

disruptive

stabilising

Question 14

stabilising natural selection (2)

Answer 14

selection pressure removes extreme variation

favours the average

Question 15

directional natural selection (2)

Answer 15

favors one extreme trait over other traits

e.g giraffes, antibiotic bacteria

Question 16

Disruptive natural selection

Answer 16

both extreme traits are favored over the intermediate form of the trait

Question 17

Hardy-weinberg equation (7)

Answer 17

model to predict allele frequencies in populations not evolving

p + q = 1

p^2 +2pq + q^2 = 1

p is dominant allele, q is recessive allele

p^2 = frequency of homozygous dominant genotype

2pq = frequency of heterozygous genotype in population

q^2 = frequency of homozygous recessive

Question 18

Hardy weinberg assumptions (5)

Answer 18

population is large

no immigration or emigration

mating is random

no mutations ocurring

no natural selection ocurring

Question 19

artificial selection (2)

Answer 19

humans selectively breed desired traits

e.g corn