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Biology > 7 Populations, Evolutions And Inheritance > Flashcards

7 Populations, Evolutions And Inheritance Flashcards

1
Q

What is a Species

A

. Organisms that can interbreed to produce fertile offspring

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2
Q

What is a population

A

. Group of the same species in the same area at the same time

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3
Q

What is a community

A

. Populations of different species in the same area

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4
Q

What is an ecosystem

A

. All the biotic and abiotic factors in an environment

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5
Q

What is a habitat

A

. Small part of an ecosystem where population lives

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6
Q

What is a niche

A

. The niche of a species is its role in an ecosystem
. Minimises competition increasing survival and reproductive success

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7
Q

What is carrying capacity And how can it be altered

A

. population of each species than ecosystem can support
. Can Be altered by natural or human activity

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8
Q

What is interspecific competition

A

. Between different species, The more similar the niches, the more competition

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9
Q

What is intraspecific competition

A

. Between the same species, often between territories or meets

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10
Q

Estimate the size of a population of sundews in a small Marsh

A

. Use the grid or divide area into squares
. Method of obtaining random coordinates E.G.random number generator
. Count percentage covering quadrat
. Use a large sample and calculate mean

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11
Q

How can you calculate the total population from Mark release recapture method

A

N=(Number marking first catch)x(Total number in second couch)/number of recaptures in second catch

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12
Q

When is Mark release recapture used and what are the rules of it

A

. Used on motile species

. Random collection, large sample size, ethical treatment, Mark must not act as a selection pressure, must give time to mix with population

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13
Q

What is succession

A

. The gradual directional change of a community due to changing abiotic and biotic conditions over time

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14
Q

What is primary succession

A

. HOSTILE environment
. Slow-growing, specialise species (pioneer species) begin growing
. Pioneers die, decomposed by microorganisms so formation of soil, less hostile
. different species colonise, pioneers outcompeted by better adapted new species
. Biodiversity increases a little
.  increases habitats and variety food
. climax community reached, most stable due to most different habitats, food variety

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15
Q

Describe and explain how succession occurs

A

. Colonisation by pioneer species
. Pioneer species change environment
. Environment is less hostile for new species
. Change increases biodiversity
. Climax community reached

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16
Q

What is secondary succession

A

. Community is damaged, soil was left, plants colonise

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17
Q

What is conservation

A

. The maintenance of biodiversity involving humans

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18
Q

What is genetic diversity

A

. The number of different alleles of genes in a population

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19
Q

What can cause genetic diversity

A

. Dna mutations
. Crossing over
. Independent segregation
. Random fertilisation

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20
Q

Explain natural selection

A

. Random mutation results in new alleles of a gene
. Selection pressures exist in the environment
. New allele might be beneficial leading to increased survival and reproductive success
. Allele pastsed on to offspring
. Over generations allele increases in frequency causing changing gene pool

21
Q

What is a gene pool and why is it beneficial to have a large one

A

. Collection of all alleles for all of the organisms genes
. Species that is more genetically diverse is more stable and more likely to adapt to survive if selection pressure changes

22
Q

What is the bottleneck affect

A

. A random reduction in population size
. Alters gene pool by chance and causes some alleles to increase some to decrease

23
Q

What is the founder effect

A

. Migration of a small number of the population that was the gene pool by chance
. New population will increase over time but some alleles have increased and others decreased

24
Q

What is directional selection

A

. Caused by natural selection
. Occurs when environment changes
. Organisms with extreme alleles more likely to survive and reproduce
. Overtime most population will have extreme allele
. Example is antibiotic resistant bacteria

25
What is stabilising selection
. Individuals with alleles for middle range more likely to survive and reproduce . Occurs when environment is stable . Conditions for average Alelle almost favourable . Average hourly or shift towards the middle of the range
26
What is disruptive selection
. Selection works against the mean . Increases frequency of extreme alleles and reduces moderate traits
27
What is allopatric speciation
. CAUSED BY GEOGRAPHICAL ISOLATION Then reproductive isolation . Have separate gene pause due to mutation caused by different selection pressures . Different alleles passed onto offspring . Different alleles change in frequency, can’t reproduce to make fertile offspring . Apparently disruptive selection
28
What is sympatric speciation
. Caused by random mutation resulting in reproductive isolation causing separate gene pools . Different alleles passed on to offspring . Causes disruptive selection . Results in two species that cannot produce to create fertile offspring
29
What is a locus
. Location of a gene on a chromosome
30
What are diploid and haploid
. Diploid refers to cells that contain two sets of chromosomes in the nucleus . Haploid refers to cells that contain only single copy of each chromosome in the nucleus
31
What does the word allele, recessive allele, dominant allele, and co dominant alleles mean
. Allele - one of a number of alternative forms of a gene . Recessive allele – only expressed in phenotype when both alleles are recessive . Dominant allele - allele that is always expressed in phenotype of an organism . Codominant – would both alleles are expressed in the phenotype
32
What do homozygous and heterozygous mean
. Homozygous – are both alleles for the same for a particular gene . Heterozygous – alleles are different for a particular gene
33
What does it mean to be a carrier
. Possessive mutated allele that can be passed to offspring but is not expressed in phenotype
34
What is genotype and phenotype
. Genotype – genetic constitution of an organism . Phenotype – characteristics of an organism due to its genotype and interaction with the environment
35
What is autosomal linkage
. When genes on the same chromosome are inherited together
36
What is sex linkage
. When a genes locus is on a sex chromosome
37
What is epistasis
. Expression of a gene affects the expression of another gene at a different locus
38
What often makes observed ratios of phenotype different to expected
. Random fertilisation . Small sample size . Linked genes . Epistatic genes
39
What is the difference in phenotype between complete dominance and co-dominance
. Complete dominance – heterozygote will have same phenotype as the dominant trait . Co-dominance – heterozygote shows a new phenotype E.G.pink from red and white
40
I don’t really get Autosomal linkage so when you have more time please look back over this
. Chat help this isn’t funny . Found this truly unhelpful card moments before mock no.1 this is actually unfunny please do some5ing about this future me this isn’t good . Just found this again the day before my last mocks, future me please actually fix it this time this isn’t funny at all
41
Why do doctors use pedigree analysis charts
. To show how genetic disorders are inherited in a family . Can’t find the probability that someone will inherit a condition
42
How can doctors work out if An allele is sex linked
. Look at fathers and daughters, affected father cannot have unaffected daughter if dominant sex linked allele is on X so must be recessive
43
When I chi square test used
. To determine whether the difference between an observed and expected frequency is statistically significant or due to chance
44
 what are the steps are Used in a chi square test
1. Null hypothesis (no significant difference between observe than expected frequency) 2. Find expected frequency is 3. Find try squared value - x^2 = (O-E)^2/E 4. Determine degrees of freedom (phenotypes - one, Then use degrees of freedom table and find value relating to phenotype and .05, this is critical value) 5. Find probability value 6. value less than critical value, p is less than .05 so not significant etc.
45
What is genetic drift
. Founder effect or genetic bottleneck, due to chance
46
What is the hardy Weinberg principle equation
. P + q = 1 . P^2 + 2pq + q^2 = 1
47
What are the five assumptions of hardy Weinberg principle
There will be no change to allele frequency as long as: . Random mating occurs . No natural selection for/against alleles . Large population size . No immigration/emigration . No mutations
48
What does the hardy Weinberg principle predict
. Allele frequency will not change from generation to generation if all assumptions remain true

Biology (6 decks)

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