Explain how incomplete dominance can result in an apparent “blend.” What will be an ideal response?
ANSWER: With incomplete dominance, one allele is not fully dominant over the other, so the
heterozygous phenotype is an intermediate blend of the two homozygous phenotypes. A gene
that affects flower color in snapdragons is an example (Figure 13.11). One allele of the gene
(R) encodes an enzyme that makes a red pigment. The enzyme encoded by a mutated allele
(r) cannot make any pigment. Plants homozygous for the R allele (RR) make a lot of red
pigment, so they have red flowers. Plants homozygous for the r allele (rr) make no pigment,
so their flowers are white. Heterozygous plants (Rr) make only enough red pigment to tint
their flowers pink. A cross between two heterozygous plants yields red-, pink-, and whiteflowered
offspring in a 1:2:1 ratio.
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Many birds, such as seagulls which rarely drink fresh water, deal with the osmotic stress of taking in
large quantities of salt in their food mainly by
a. active transport of ions into the body through their feet. b. excreting nitrogenous wastes through their kidneys as urea. c. active transport of ions out of the body by chloride cells. d. excreting excess salt through the actions of specialized salt glands in their heads. e. maintaining high levels of urea and trimethylamine oxide in body fluids.
Predict which food item would be most effective at increasing metabolic rate via digestion of same.
A. baked potato B. meat C. cola D. butter
The peritoneum can function as a dialyzing membrane in a procedure called ________
Fill in the blank(s) with correct word
Although Burkholderia cepacia could be very useful in bioremediation programs, it is not feasible to use it. Why?
What will be an ideal response?