biodiversity (CMO)

Question 1

what is a selection pressure

Answer 1

they are environmental pressures which effect the chance of survival e.g. resource availability

Question 2

what is stabilizing selection

Answer 2

relatively constant change over generations

Question 3

what is directional selection

Answer 3

gradual change over generations
natural selection in which alleles change over time, this typically occurs in environments where change in environment occur e.g. Darwin’s finches

Question 4

what is disruption selection

Answer 4

maintain high frequency of two different alleles
occurs within any population e.g. Darwins finches
for: both extremes
against: moderate traits

Question 5

what is natural selection

Answer 5

the theory that organisms with advantageous traits survive and reproduce thus passing the trait to the offspring

Question 6

what is biodiversity

Answer 6

it is the variation between all forms of life

Question 7

why is biodiversity important

Answer 7

it allows ecosystems to be resilient to change within the environment

Question 8

what is an ecosystem / habitat diversity

Answer 8

it is the range of different ecosystems within a region
larger habitat frequency = higher biodiversity

Question 9

what is an example of a region with high biodiversity

Answer 9

the coral reef
has high frequency of species and individual species within communities

Question 10

what is an example of a region with low biodiversity

Answer 10

the desert
species Widley dispersed and have harsh conditions

Question 11

what is species rich

Answer 11

a species with a high frequency

Question 12

why is maintaining biodiversity important

Answer 12

morally
stability of ecosystems
environmental
economic
aesthetic
agriculturally

Question 13

what is the index diversity equation

Answer 13

d= N(N-1)
———-
En (n-1)

Question 14

what is genetic diversity

Answer 14

it is the different number of alleles in genes

Question 15

what is genetic isolationism

Answer 15

when two groups are isolated so become genetically isolated, as they no longer interbreed / exchange genetics so evolve independently

Question 16

what is comparing characteristics

Answer 16

it is quick but mot very reliable e.g. comparing features like fur

Question 17

what are measurable characteristics

Answer 17

features we can analyse and measure e.g. DNA analysis

Question 18

how do we compare nucleotides

Answer 18

DNA is extracted from nuclei of organism can be blood or fossil /skin
DNA is then processed, base sequence compared
more similar = closer related

Question 19

mitochondria DNA analysis

Answer 19

analyse DNA from mitochondria
zygote only contain mitochondria from maternal egg cell
no crossover mean mutation
e.g. mitochondria eve

Question 20

MRNA analysis

Answer 20

located in cytoplasm easier to use than DNA. this is used to produce CDNA which contain the coding region of gene. compare this using universal protein cytochrome C.

Question 21

amino acid comparison

Answer 21

amino acid easy to isolate from cell
the AA sequence is compared. protein must be the same e.g. haemoglobin
similar sequence = similar species

Question 22

how have humans impacted biodiversity

Answer 22

as the population increase this led to an increase in:
mass extinction
climate change
competition for resources
introduction of new species
hunting
loss of habitat

Question 23

what are traditional crops

Answer 23

sown in spring
gap between harvesting 5-6 months

Question 24

what are modern crops

Answer 24

sown in autumn
gap between ploughing and harvesting 1-2 weeks , this leaves little time for birds to get food. if no foot available biodiversity of birds declines

Question 25

what is organic farming

Answer 25

farming that involves no harmful chemicals or pesticides reduces the amount of insects and animals ingesting harmful chemicals

Question 26

what impact are bees having on diversity

Answer 26

bees pollinate crops but there population is rapidly declining. the species are facing extinction extensive farming and monoculture reduces biodiversity pesticide also affect the population

Question 27

why do farmers use pesticides

Answer 27

farms are not economically friendly as it is costly to run environmentally friendly higher yield with ,modern farming

Question 28

what is inerspecific variation

Answer 28

this refers to the vast genetic diversity between individuals from different species

Question 29

what is intraspecific variation

Answer 29

this refers to variation within species

Question 30

what are the benefits of random sampling

Answer 30

ensure there is no bias reduces chance we can lower the risk of bias by increasing sample size

Question 31

what are anatomical adaptations

Answer 31

physical features e.g. long necks on giraffe hairy frogs bones in feet break and bones are used as weapons. tissue heals and regenerates

Question 32

what are physiological adaptations

Answer 32

internal body adaptions which help organisms to survive e.g. komodo dragons have high levels of bacteria in mouth when bite prey they die of infection

Question 33

what are behavioural adaptations

Answer 33

can be passed on from parent or learnt at a very young age if behaviour beneficial more likely to survive and pass advantageous behaviour on to kid e.g. Christmas island crabs

Question 34

what is genetic drift

Answer 34

a change in allele frequency due to chance, this can cause extinction of gene variants so lowering gene pool. could cause rare alleles to become prominent

Question 35

what is a genetic bottleneck

Answer 35

a catastrophic event that occur resulting in a population size to reduce by 50%

Question 36

what is a founder effect

Answer 36

occurs when a few individuals become isolated from a population the new population will become the founders

Question 37

what is speciation

Answer 37

it is the formation of new species from an existing species

Question 38

what is allopatric speciation

Answer 38

this is a result of geographic isolationism this occurs when population is geographically isolated e.g. lakes, motorways the population cannot exchange genetics different selective pressure or genetic drift result in the evolution of a new species

Question 39

what is sympatric speciation

Answer 39

occurs with no geographic barrier, they live within the same environment but no gene flow between them ecological separation when species start to adapt living in same environment the adaption occurs over generations and can result in new species