biodiversity

Question 1

what should you include in descriptions of control variables?

Answer 1

description of how these variables should be controlled e.g. with apparatus

Question 2

how can you tell on a diagram of an evolutionary tree if a species isnt extinct?

Answer 2

if the line continues

Question 3

what is genetic info passed between during crossing over and what does this lead to different combinations of?

Answer 3

homologous chromosomes
new combinations of alleles

Question 4

what undergoes independent assortment and what does this lead to new combinations of

Answer 4

homologous chromosomes undergo independent assortment
this leads to new combinations of chromosomes in gametes

Question 5

how does fertilisation result in genetic variety in an individual?

Answer 5

random fertilisation of sperm and ovum haploid nucleus produces a genetically unique zygote

Question 6

classification system order a

Answer 6

doctor
king
penis
cock
overcame
family
genitalia
surprise

domain
kingdom
phylum
class
order
family
genus
species

Question 7

broad definition of species

Answer 7

-reproductively isolated (can only breed to produce fertile offspring with other members of their species
-similar behaviour, morphology and physiology
-share 100% of their genes

Question 8

habitat

Answer 8

area where an organism lives

Question 9

give 3 ways in which human activity is impacting biodiversity

Answer 9

-deforestation, destroying natural habitats so organisms that live there wont have the resources they need to survive
-over exploitation like whaling decreasing numbers of aquatic species
-COMPETITION FROM INTRODUCED SPECIES OUTCOMPETING NATIVE SPECIES FOR RESOURCES AND REDUCING THEIR NUMBERS
-POLLUTION, MICRO PLASTICS IN AQUATIC ENVIRONMENTS KILLING AQUATIC SPECIES

Question 10

give reasons why we should conserve species

Answer 10

-aesthetic reasons, many people take pleasure in being surrounded by many different species/being in diverse ecosystems
-ethical reasons: humans should be responsible for the protection of the natural environment
biodiversity should be preserved for the benefit and enjoyment of future generations
-economic reasons: zoos attract tourists, can help national and local economies
-practical reasons: humans can use many different species for various products
-ecological reasons:
habitat loss can have a dramatic ecological effect, many species in a habitat are reliant on each othr for resouces or fertilisation, if some go extinct others may not be able to survive

Question 11

what can be calculated to give an idea of the biodiversity in an area?

Answer 11

-variety of species and their abundance
-genetic variety within a species
-the range of different ecosystems and habitats

Question 12

species richness

Question 13

hardy-weinberg

Question 14

heterozygosity index

Answer 14

genetic diversity within a species

total number of heterozygous individuals/total number of individuals within a population

greater the H% the greater the genetic diversity

Question 15

diversity index

Question 16

species evenness

Question 17

chi squared

Question 18

molecular phylogeny

Question 19

genetic drift

Answer 19

some alleles not passed down to offspring bybchance
genetic variety in a population decreases which makes species more at risk of extinction if environment changes
occurs in small populations with limited numbers of sexually mature adults

Question 20

types of adaptation:
behavioural

Answer 20

actions an organism carries out

Question 21

physiological

Answer 21

internal bodily processes within cells, tissues or an organsim that help it to survive its environment

Question 22

anatomical

Answer 22

structures that can be seen when we observe an organism

Question 23

how can classification be a measure of biodiversity?

Answer 23

-if we can group organisms based on their shared characteristics we can quantify number of different species measure their relative abundance
and measure genetic variety within species

Question 24

reproductive isolation

Answer 24

when 2 organisms can no longer interbreed to produce fertile offspring

alleles or phenotypes of some individuals in a population prevent them from being able to interbreed to produce fertile offspring with individuals who dont have these alleles or phenotypes

random mutations and evolution by natural selection can lead to these new alleles and phenotypes

evolution that 2 different populations may experiene may be different as they may be exposed to different selection pressures meaning different alleles will be advantages to aid in survival of these selection pressures. Individuals in each population with the different advantageous alleles are more likely to survive and reproduce so different alleles will be more common in different populations until the alleles and phenotypes present within each population are so different that theyre reproductivly isolated

Question 25

sympatric speciation

Answer 25

new species evolve from same original species whilst inhabiting same geographical region

Question 26

how can sympatric speciation occur

Answer 26

dont really need to know still results in reproductive isolation may be strong sexual selection for specific traits within same population may isolate some groups

Question 27

allopatric speciation

Answer 27

new species evolves from same origional species due to a geographical barrier when 2 populations are geograpically separated, no gene flow/gene exchange can occur between them

Question 28

describe how speciation leads to reproductive isolation

Answer 28

-barrier means theres no more gene flow between 2 populations -2 populations will be exposed to different selection pressures -different alleles will be advantageous in different environments so advantageous alleles selected by natural selection in the 2 populations will be different -different phenotypes will result in separate populations -over time populations may begin to differ behaviourally, anatomically or physiologically -these changes may mean that theyre no longer able to interbreed to produce fertile offspring

Question 29

function of peer review

Answer 29

ensure validity of a scientists findings individuals who work in the same specialism can check their work, repeat same experiments and look to see if they get similar results which provide corroborating evidence