In the past decades, direct-to-consumer (DTC) genetic tests have become widespread.
Are such tests approved by the Food and Drug Administration?
How many gene pairs are involved in generating a typical 1:4:6:4:1 ratio?
How are electrical impulses propagated from neuron to neuron?
What is an allosteric molecule?
What is the original source of genetic variation in a population? Which natural factors
affect changes in this original variation?
A color-blind, chromatin-positive male child (one Barr body) has a maternal
grandfather who was color blind. The boy’s mother and father are phenotypically
normal. Construct and support (using appropriately labeled diagrams) a rationale
whereby the chromosomal and genetic attributes of the chromatin-positive male are
fully explained.
At what stage of the meiotic cell cycle and during what chromosomal configuration
does crossing over occur?
The trait for medium-sized leaves in iris is determined by the genetic condition PP’.
Plants with large leaves are PP, whereas plants with small leaves are P’P’. The trait for
red flowers is controlled by the genes RR, pink by RR’, and white by R’R’. A cross is
made between two plants each with medium-sized leaves and pink flowers. If they
produce 320 seedlings, what would be the expected phenotypes, and in what numbers
would they be expected? Assume no linkage.
It has been found that a particular “+ ” combination of frameshift mutations in gene X
gives a wild-type phenotype, whereas a ” +” combination gives a mutant phenotype,
even though the sites of insertion/deletion are the same. How might these results be
explained?
Chromosomal regions that represent evolutionary vestiges of duplicated copies of genes
that have underdone sufficient mutations to render them untranscribable are called
________.
Transcription factors appear to be important molecules relating to the regulation of gene
activity. Two general classes of transcription factors exist in eukaryotes. Briefly
describe each.
One of the Hardy-Weinberg assumptions states that the population is infinitely large.
What influence might a small population size have on a Hardy-Weinberg equilibrium?
What is the name of a normal gene that serves to promote cellular division?
If two different auxotrophic strains are placed in a liquid medium culture tube,
prototrophic strains can sometimes be subsequently recovered. Name several
mechanisms by which this is possible.
We often refer to the host of genetic factors in the genome that have an influence on a
particular gene’s expression as its genetic background. What influence does genetic
background have over the phenotype of the organism?
Recombinational repair is activated when damaged DNA has escaped repair and the
distortion disrupts the process of replication. Which gene is responsible
recombinational repair?
List four terms used to describe the normal morphologies, with respect to arm ratio, of
eukaryotic chromosomes.