diversity (topic 4)

Question 1

what is genetic diversity

Answer 1

number of different alleles of genes in a population
(all members of the same species have the same genes)

Question 2

population def

Answer 2

a group of individuals of the same species
that live in the same place and can interbreed

Question 3

species def

Answer 3

one or more populations
group of similar organisms that can breed together to produce fertile offspring

Question 4

if there is a greater number of different alleles in a species, the genetic diversity is…

Answer 4

greater

Question 5

genetic diversity enables natural selection how

Answer 5

greater the genetic diversity, more likely some individuals within a population will survive environmental change

wider range of alleles = wider range of characteristics

so greater probability that some individuals possess a characteristic that suits it to new environment settings

Question 6

allele frequency def

Answer 6

number of times an allele occurs in a gene pool

Question 7

gene pool def

Answer 7

total no of alleles in a particular population at a specific time

Question 8

how does reproductive success occur (and allele frequency) (basically steps of natural selection)

Answer 8

• within any population of a species there is a gene pool with a wide variety of alleles
• random mutations of alleles may result in new alleles of a gene, most are harmful
• however sometimes the new allele of the gene may give its possessor an advantage over others
• these individuals are better adapted so are more likely to survive in competition with others
• also more likely to obtain resources so grow more and live longer
• better chance of breeding successfully and reproducing (so pass on their alleles to next generation)
• the new allele that gave the parents advantages is more likely to survive and reproduce successfully
• over time, no of individuals with new advantageous allele will increase as less advantageous alleles decrease

Question 9

species diversity : species richness and proportion

Answer 9

number of different species in an area at a given time
proportion of community made up of an individual species

Question 10

diversity index equation

Answer 10

N(N-1)
————
Σ n(n-1)

N = total no of organisms in ALL species
n = total no of organisms of EACH species
Σ = sum of

Question 11

which farming practices have reduced biodiversity
(opposite of these for how to improve it)

Answer 11

removal of hedgerows
creating monocultures
filling in ponds
over-grazing of land (woodland can’t be regenerated)
pesticides (reduce other species as they compete for light, water, minerals) (-use GM crops instead)
inorganic fertilisers
absence of crop rotation (-use legumes with nitrogen fixing bacteria one cycle)

Question 12

limiting factors for bacterial growth

Answer 12

food supply
light => more phs, carrying capacity higher but also competition higher
competition
predation
temperature => low temp low metabolic rate so carrying capacity is lower. also optimum temp and denaturing
pH => enzyme activity
water => if not adapted to dry conditions will die

Question 13

mnemonic for classification

Answer 13

donkey kong plays chess on ferry going spain (don’t kiss peoples chodes or fat gay spacs)

domain, kingdom, phylum, class, order, family, genus, species

Question 14

3 domains

Answer 14

bacteria, archaea, eukarya

Question 15

5 kingdoms

Answer 15

animalia
plantae
fungi
protoctistae
bacteria

Question 16

density dependent factor def

Answer 16

factor who’s effect on the size of a pop will vary WITH pop density

Question 17

density independent factor def

Answer 17

any factor effecting size of pop, REGARDLESS of density of that population