Quiz
GEGE2001 Quiz 1
Perguntas do quiz (10)
1In a pedigree, autosomal recessive inheritance for a rare trait is characterised by the following:
- AMany more males than remales having the trait
- BMales with the trait always having daughters with the trait
- COffspring of two parents with the trait have the trait
- DTwo of the other answers
- EOften appearing with mating between relatives without the trait
2A test cross refers to a:
- ANone of the other answers
- BReciprocal intercross among the F1 individuals
- CReciprocal cross of the F1 to either parent
- DBackcross to the dominant parent
- ECross where one of the parents is homozygous recessive
3A cross between two different pure-breeding breeds of “coloured wing parrots” (red wing x white wing) gave the following progenies in the F1 and F2 generations: F1 = all pink; F2 = ¼ red, ½ pink, ¼ white. These results indicate that:
- APink is dominant over red and white
- BRed is dominant to white
- CRed is controlled by a different gene than white
- DRed is dominant to pink and white
- ENone of the other answers
4The principle of independent assortment means that:
- AThere will always be a 3:1 ratio in the F2
- BTwo of the other answers
- CThere can be a 1:1:1:1 ratio in the testcross of a double heterozygote
- DThe two alleles of a gene in heterozygotes separate into the gametes giving a 1:1 ratio in the gametes
- EIt will occur during both cell division and gamete formation
5If a χ2 (chi-square) test of a genetic ratio gives a Probability of 0.02 (2%), then:
- AYou would be 98% sure that the results are correct
- BTwo of the other answers
- CEnables the deletion of 2% of the observed numbers on each class which do not fit the expected ratio
- DYou should reject the genetic hypothesis tested (if using the 5% significance level)
- EThe difference between the observed and expected numbers is not big enough to say the observed numbers do not fit the tested ratio
6Dominance is the determination of the phenotype by:
- AMultiple alleles
- BThe interaction of the different alleles of a gene
- CNone of the other answers
- DThe interaction between the genotypes of two or more gene loci in determining the phenotype
- EGene expression at a homozygous locus
7Complete linkage means that:
- AThe recombination fraction is 100%
- BTwo of the other answers
- CThere is no effect of dominance
- DRecombinants are not present
- EThe recombination fraction is 50%
8From a cross of sheep (Rr female parent, rr male parent), the progeny will be of genotype:
- A½ Rr; ½ rr
- BRR, Rr, or rr
- CAll rr
- DNone of the other answers
- EAll Rr
9A cross is made between two pure breeding cattle breeds, where one breed is resistant to a tick species due only to a dominant allele of a gene for resistance, and the other breed is resistant only due to a recessive allele at a different gene to the first for resistance. Both genes are autosomal. The F1 between the breeds was resistant; what is the expected ratio of resistant to susceptible cattle in the F2 generation assuming independent assortment of the two autosomal genes? (Hint:
once a cattle individual is resistant because of its genotype at one of the genes, having resistance determined by the other gene does not give increased resistance, i.e. there are only 2 phenotypes: resistant and susceptible)- A13 resistant : 3 susceptible
- B12 resistant : 4 susceptible
- C15 resistant : 1 susceptible
- D9 resistant : 7 susceptible
- EAll susceptible
10Repulsion double heterozygotes:
- ACome from the cross AAbb x aaBB
- BGive a higher frequency of recombinants than the coupling double heterozygotes
- CNever have independent assortment of the two genes
- DNone of the other answers
- ECome from the cross AABB x aabb
Informações
- Descrição
- I got 70%
- Autor
- Michael Jardine
- Idioma
- English
- Visualizações
- 126
- Etiquetas
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