What marks the end of the pre-embryonic period and the beginning of the embryonic period?
A) implantation
B) the formation of the ectoderm and endoderm in the embryonic disk
C) the formation of the morula
D) the formation of the blastocyst
E) the formation of pharyngeal arches
B
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Which of the following is not a fat-soluble vitamin? Fat-soluble vitamins may be harmful if taken in large doses, as they accumulate in our fatty tissues
a. A b. B c. D d. E e. K
Where does RNA polymerase begin transcribing a gene into mRNA?
A. Transfer RNA acts to translate the message to RNA polymerase. B. It looks for the AUG start codon. C. It starts after a certain nucleotide sequence called a promoter. D. It starts at one end of the chromosome. E. The ribosome directs it to the correct portion of the DNA molecule.
Where does the copper used for wiring and plumbing come from?
A. Most copper is found in ocean sediments. B. Most copper is mined from the ground. C. Most copper is found along riverbanks. D. All copper is mined from the surface. E. All copper is manufactured synthetically in factories.
What are the two types of aquifers?
A- thick and thin B- shallow and deep C- tapped and untapped D- confined and unconfined E- renewable and nonrenewable