In selection, one extreme phenotype is the fittest while others are selected against.
A. convergent
B. disruptive
C. artificial
D. stabilizing
E. directional
E. directional
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A farmer is concerned that if she plants seeds for her next harvest, many of them will remain dormant and fail to grow. Depending on the plant, what steps can the farmer take to ensure that many of her seeds will germinate?
A. She can treat her seeds with red light prior to planting. B. She can put her seeds in the refrigerator for a few months before planting. C. She can rub her seeds with sand paper prior to planting. D. She can feed the seeds to her cows and collect them after they have passed through the animals' digestive tracts.
A 40-year-old patient has been diagnosed with cancer. Sequencing of cancer cell genomes reveals a high frequency of G/C to A/T base pairs conversion. The DNA repair system that is most likely deficient in this patient is the
A) base excision repair pathway. B) SOS repair pathway. C) nonhomologous end-joining pathway. D) nucleotide excision repair pathway. E) synthesis-dependent strand annealing pathway.
To test whether the XFF signal system is similar to that of epinephrine, you microinject a nonhydrolyzable analogue of GTP into an XFF-responsive cell. If the XFF mechanism is similar to that of epinephrine, you would expect the cellular response to be
A) blocked completely. B) prolonged. C) delayed. D) 50 percent of normal. E) It is not possible to predict without knowing how many receptors are present on the cell.
Which of the following is a difference between how a frog and chytridiomycetes obtain energy?
A. Frogs ingest their food; chytridiomycetes secrete digestive enzymes. B. Chytridiomycetes ingest their food; frogs secrete digestive enzymes. C. Frogs are heterotrophs; chytridiomycetes are phototrophs. D. Chytridiomycetes are heterotrophs; frogs are phototrophs. E. Frogs are autotrophs; chytridiomycetes are phototrophs.