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Biology > 7 Populations, Evolutions And Inheritance > Flashcards

7 Populations, Evolutions And Inheritance Flashcards

(48 cards)

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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

Study These Flashcards
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

Study These Flashcards
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

Study These Flashcards
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

Study These Flashcards
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

Study These Flashcards
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 . future molly here dont feel like fixing this might just fuck around and find out tbh xoxo
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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