In a newly fertilized egg, the vitelline layer _____
A) opens the egg's nuclear membrane to allow haploid sperm DNA to enter
B) lifts away from the egg and hardens to form a fertilization envelope
C) secretes hormones that enhance steroidogenesis by the ovary
D) reduces the loss of water from the egg and prevents desiccation
E) provides most of the nutrients used by the zygote
Answer: B
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Indicate whether this statement is true or false.
The promotion of the lactose operon in bacteria is
a. activated by a repressor protein. b. independent of glucose concentration. c. activated by lactose binding. d. regulated by RNA polymerase. e. regulated by mRNA.
Which organism would be least likely to be able to survive rapid global climate change?
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What is the distinction between the terms "proto-oncogene" and "oncogene"?
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