Spina bifida occurs due to a defect in the development stage
A. prior to cleavage.
B. prior to neurulation.
C. prior to fertilization.
D. after gastrulation.
E. after organogenesis.
D. after gastrulation.
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What nucleotide change is a shared derived character for species A, B, and C, but not for species G?
Note: A,T,G, and C refer to nucleotide bases, and the numbers refer to the position of the base in the nucleotide sequences. For example, A6 refers to an adenine at the sixth position.
A. Changing the second G to an A is common to species A, B, and C, but not to species G.
B. Changing the fifth T to a G is common to species A, B, and C, but not to species G.
C. Changing the second G to a T is common to species A, B, and C, but not to species G.
D. Changing the second G to an A and the fifth T to a G is common to species A, B, and C, but not to species G.
E. None of these show a change in derived characteristics for A, B, and C that are not found in G.
Which of the following taxa are known to contain species that cultivate fungi for food? Check all that apply.
_____ leaf-cutting ants _____ humans _____ termites _____ beetles _____ nematodes
The most abundant gas in the atmosphere is
a. carbon dioxide. b. hydrogen. c. nitrogen. d. oxygen
cDNA sequences are expressed sequence tags (EST) that identify protein coding genes. Indicate whether the statement is true or false