________ bonds are responsible for the chemical affinity
between A and T (or G and C) nucleotides. Correct Answers
hydrogen
_______-form DNA spirals to the right and is the major form of
naturally occurring DNA molecules. Correct Answers B
A coefficient of coincidence of 0.5 in a region of three genes
means that half as many double crossovers were observed as
would have been expected if crossovers in the two intervals
were independent. Correct Answers True
A female mouse from a true-breeding wild-type strain was
crossed to a male mouse with apricot eyes (ap) and gray body
(gy). The F1 mice were wild-type for both traits. When the F1
were interbred, the F2 were distributed as follows: Correct
Answers ap and gy are X-linked and 10 map units apart.
A linkage group includes all of the genes on a chromosome,
including genes that are so far apart from each other on a
chromosome that they assort independently during meiosis.
Correct Answers True
A two-point testcross was performed. Based on the frequencies
of progeny in each class, a chi-square test for goodness of fit
allows you to accept the null hypothesis that the two genes are
unlinked. Which ONE of the following is sufficient to allow you
to accept the null hypothesis? Correct Answers The probability
, is greater than 1/10 that the expected and observed frequencies
occurred by chance.
A virus that infects bacterial cells is known as a Correct
Answers bacteriophage
Another name for a chromosome is a _______, because it
contains alleles that are often inherited together. Correct
Answers linkage group
Avery and colleagues purified a white substance as the
transforming principle. Treating this substance with enzymes
that destroyed RNA, protein, or polysaccharides did not affect
its ability to transform cells, but an enzyme that degrades DNA
destroyed the transforming ability. These results suggested that
Correct Answers the transforming principle appeared to be
DNA
Chiasmata are structures that show where recombination
occurred between sister chromatids. Correct Answers False
Chiasmata can be seen through a light microscope and are sites
of recombination. Correct Answers True
Crossing-over takes place in bivalents (tetrads) consisting of
______ chromatids, and one crossover involves _______
nonsister chromatids. Correct Answers 4; 2
DNA is localized mainly in the Correct Answers
chromosomes.