Zusammenfassung der Ressource
Frage 1
Frage
DNA replication:
1. Was first observed in Darwin’s finches
2. Must be accurate in order to transmit the genome to the next generation
3. Is accurate in germ cells and error prone in somatic cells
4. Must include some errors in order to produce variation
Antworten
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1 and 3
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2 and 4
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1 only
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1 and 2
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3 and 4
Frage 2
Antworten
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Repairs pyrimidine dimers
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Uses UV light and visible light sequentially
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Causes a bulge in the DNA helix
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Utilises UV light for photolyase activity
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Does not occur in humans due to the use of sunscreens
Frage 3
Frage
Siamese cats show a range of coat colours on a single individual because:
Antworten
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They are homozygous for a missense mutation in TYR that produces a heat sensitive tyrosinase protein
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Coat colour is a polygenic trait with many genotypes possible in the breed
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The breed was originally formed by the mating of a pale coat cold-climate cat and a brown coat warm-climate cat
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Cats arise from the fusion of 2 or more zygotes causing genetic mosaicism
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Frequent somatic mutation occurs in the TYR genes when cats are not kept warm
Frage 4
Frage
Microsatellites used as genetic markers because:
Antworten
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They can be assayed by PCR and size separation of the DNA fragment amplified
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None of the other answers
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They give inconsistent results
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They always have high rates of recombination when assayed with visible markers
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They are very rare
Frage 5
Antworten
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None of the other answers
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In humans are circular, not linear
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Cannot be used to make predictions in pedigrees
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Can be given in units of cM (centiMorgans)
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Have no relationship to genetic recombination
Frage 6
Frage
The Hardy-Weinberg Equilibrium always results in:
Antworten
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Constant gene and genotype frequencies from generation to generation
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25%, 50%, and 25% as the frequencies of the three genotypes AA, Aa, and aa respectively in all cases
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A tendency for the dominant allele to go towards fixation
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A reduction in the frequency of heterozygotes
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None of the other answers
Frage 7
Antworten
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Changes gene frequencies quickly
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Results in a stable frequency of heterozygotes
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None of the other answers
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Results in the frequency of heterozygotes being halved each odd generation
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Can only be done in plants, not animals
Frage 8
Frage
In a certain human population, colour-blindness is 20X more frequent in males than females. This means that:
Antworten
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9.5% of the females are carriers of the colour-blindness gene
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The allele for colour-blindness has a frequency of 0.5
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There is selection on this characteristic
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Females can not be colourblind
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0.25% of the females are not colour-blind
Frage 9
Frage
When a population is small, the effect is:
Antworten
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Higher mutation rates
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None of the other answers
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That gene frequencies will change at random over time, and certain alleles may become fixed
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Heterozygotes will steadily increase in frequency
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That recessive alleles will always disappear
Frage 10
Frage
In a population mutation from the A to a allele has a frequency of 0.0001, while the reverse mutation rate is 0.0009. What is the equilibrium frequency of the a allele?