Which of the following is not evidence for the rearrangement mechanism in the immune system evolving from transposons?
A. Transposases have sequence homology to immunoglobin genes.
B. The mechanism for RAG1 and RAG2 resembles the transposition mechanism. In the reaction, an intermediate is formed transiently that has hairpins at the ends of the sequences being removed.
C. The fragment deleted from between the V segments during rearrangement can be inserted into DNA by RAG1 and RAG2 in vitro.
D. The fragment deleted from between the V segments during rearrangement has structural similarity to transposons.
E. All of the choices given provide evidence.
A
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What is one reason why women with the genotype XXX are not phenotypically different from an XX female?
A. Because only one X is active in each cell, regardless of how many X chromosomes there are in a cell. B. Because the X chromosome only carries genes dealing with being a female, so having another one doesn't matter. C. Because the extra X chromosome only becomes active in nonreproductive areas of the body. D. Because we have enzymes that will recognize and degrade the extra X chromosome. E. None of the answer options is correct.
A simple sugar is composed of equal parts carbon and water, which gave rise to the general name of any sugar as a ________.
Fill in the blank(s) with the appropriate word(s).
Kin selection theory would lead us to predict that:
a. children in stepfamilies are injured more frequently than those living with their biological families. b. children in stepfamilies are injured at exactly the same frequency as those living with their biological families. c. children in stepfamilies are injured less frequently than those living with their biological families. d. children in stepfamilies are less likely to engage in sexual activities with their family members than children living with their biological families. e. None of the above; kin selection theory cannot make predictions about human behavior.
Which sequence of steps is the correct order for cellular division?
A. anaphase, metaphase, prophase, telophase, cytokinesis B. prophase, metaphase, anaphase, telophase, cytokinesis C. prophase, metaphase, anaphase, cytokinesis, telophase D. cytokinesis, metaphase, anaphase, telophase, prophase