Cacti in the deserts of southwestern North America and some euphorbs of the deserts of Africa, have barrel-shaped stems, short-lived leaves, and spines, yet these two types of plants are from different evolutionary lineages. This is an example of
A. selective breeding.
B. convergent evolution.
C. homologous traits.
D. transitional forms.
Answer: B
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Which variable is least likely to play a role in the destruction of the coral reefs? a. Rising sea temperatures
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Recall the caterpillar experiment in which caterpillars born in the spring looked like flowers, and caterpillars born in the summer looked like twigs. What is the most likely selective advantage for this difference in body shape?
A) Looking like their food sources allows the caterpillars to move through their environment more efficiently. B) Development into the adult moth form is faster for caterpillars shaped like twigs than like flowers. C) Looking like their food source lets the caterpillars blend into their surroundings, reducing predation. D) Looking like their food source will increase the caterpillars' feeding efficiency; this would increase their growth rate and survival rate.
The mechanism that "breaks" the linkage between linked genes is
A) pleiotropy. B) codominance. C) independent assortment. D) crossing over.