Suppose you used the NCBI Blast server to look for a match
to a fruit-fly gene.
Suppose further that the best alignment contained this
section of an alignment:
Hit from database: XXXXXXXXXXXXXXNFSTSQ
user sequence: SLEAEAAPASISPSNFSSSQ
What do the Xs signify?
Bootstrap analysis evaluates evolutionary trees by sampling
columns from the original alignment with replacement
(multiplying or removing some of them) and computing a
proportion of times that a particular branch appears in the
resulting trees. What is the main idea behind this approach?
People who can roll their tongues contain a dominant allele
for tongue rolling. If people do not contain the tongue
rolling gene, then they cannot roll their tongue no matter
how hard they try.
Consider the following situation: If a homozygous dominant
tongue roller mates with a homozygous recessive non-tongue
roller, then what is the probability of the offspring
inheriting the tongue rolling gene?
The gene for tallness (T) is dominant over the gene for
shortness (t) in pea plants. A homozygous dominant pea
plant is crossed with a heterozygous pea plant, and 200
seeds are produced. Approximately how many of these seeds
can be expected to produce plants that are homozygous