Question

U IS MOST COMMOT a population as a Select from the terms below to answer questions #17-22. One term is not used. R) Genomic imprinting S) Methylation T) Sex-influenced inheritance U) Maternal inheritance V) Sex-limited inheritance W) Complementation X) X-linked inheritance 17) Pattern baldness is controlled by two alleles: B, b. Females are bald if they are homozygous (BB) but males only need one allele B to be bald. This trait is an example of 18) A mother passes on her mitochondrial genes to all of her children, and a father passes his mitochondrial genes to none of his children. This is an example of 19) For some genetic disorders, the expression of the phenotype depends on whether an allele is inherited from the mother or father. An example in mice occurs with a gene for insulin-like growth factor II (g/2): a heterozygous mouse will be dwarf if its normal allele comes from his mother and its mutant allele comes from his father. This is an example of 20) in chickens, a single pair of alleles controls the feathering pattern of their neck and tail. Male chickens (roosters) may show cock or hen feathering: females (hens) only show hen feathering, never cock feathering. This is a case of 21) Two recessive mutations that cause a 'wingless' mutation in Drosophila are independently isolated. A researcher wonders whether the mutations are in the same gene or different genes, so he crosses the two strains. The outcome is that all ontspring develop normal wings. Restoration of the wild-type phenotype is due to 22) it has been discovered that some hereditary traits result from changes in the pattern of gene expression without alterations to the DNA sequence. A major mechanism for silencing gene expression is . . . ...... ***

Answer 1

Question

17.This is an example of Sex-influenced trait.

18. This is known as Maternal inheritance

19. This is an example of X-link inheritance

20. This is an example of sex-limited inheitance.

21. This is known as complementation test

22. Methylation