The variation among offspring, and the fact that they are genetically different from their parents, is due to which of the following?
random process of fertilization
random alignment of homologues during meiosis I
all of the above contribute to genetic variability in sexual reproduction
The bulldog ant has a diploid number of two chromosomes. Therefore, following meiosis, each daughter cell will have a single chromosome. There is/are ________ different possible combination(s) of genes in the daughter cells of meiosis because ________.
more than 2; cross over
Phenylketonuria is an inherited disease caused by a recessive autosomal allele. If a woman and her husband are both carriers, what is the probability that their first child will be a phenotypically normal girl?
When Mendel crossed yellow-seeded and green-seeded pea plants, all the offspring were yellow seeded. When he took these F1 yellow-seeded plants and crossed them to green-seeded plants, what genotypic ratio is expected?
Assuming independent assortment for all gene pairs, what is the probability that the following parents, AABbCc × AaBbCc, will produce an AaBbCc offspring?
Different ratios occur in crosses with single gene pairs or two gene pairs. What types of ratios are likely to occur in crosses dealing with a single gene pair?
3:1, 1:2:1, 1:1
Why is the allele for wrinkled seed shape in garden peas considered recessive?
The trait associated with the allele is not expressed in heterozygotes.
Why can you infer that individuals that are "pure line" are homozygous for the gene in question?
No other phenotype arises in a pure-line population because no other alleles are present.
Regarding an allelic pair for flower color in snapdragons, heterozygotes have pink flowers, whereas the two homozygotes have red flowers or white flowers. When plants with red flowers are crossed with plants with white flowers, what proportion of the offspring is expected to have pink flowers?
The transduction experiments done by Hershey and Chase, and the transformation experiments done by Griffith, supported the same conclusion, which was ________.
dna is the molecular substance of genetic inheritance
Watson and Crick elucidated the structure of DNA in 1953. Their research built on and helped explain the findings of other scientists, including ________.
all of the above
Once researchers identified DNA as the unit of inheritance, they asked how information was transferred from the DNA in the nucleus to the site of protein synthesis in the cytoplasm. What is the mechanism of information transfer?
David Pribnow studied the base sequences of promoters in bacteria and bacterial viruses. He found two conserved regions in these promoters (the -10 box and the -35 box). What is the function of these two regions of the promoter?
They bind the sigma subunit that is associated with RNA polymerase.
During elongation, RNA polymerase has three prominent channels, or grooves. These channels provide sites for all of the following, except ______
a site for the exit of the diphosphates removed from the nucleotide triphosphates.