Which type of blood vessels contain valves and what is their function?
What will be an ideal response
Veins contain valves to prevent blood from flowing backward. This is necessary because the venous vessels are a low-pressure system and the blood must sometimes flow against gravity, particularly in the limbs.
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The term "codon" refers to
A. a three-nucleotide sequence of DNA that codes for a protein. B. an amino acid that is coded for by three bases of DNA. C. a three-base sequence of mRNA. D. the part of a rRNA molecule where a new amino acid is added. E. the part of tRNA that is a triplet of bases that forms hydrogen bonds with complementary sequences.
The right hemisphere is usually dominant in right-handed persons
Indicate whether the statement is true or false
Describe the endocrine events that help maintain pregnancy after the blastocyst implants
What will be an ideal response?
Most human cells range from 10 to 15 micrometers in diameter. What limits how large a cell can get?
A. The relationship between its length and surface area B. A cell's lifespan C. Nutrients available in the environment of a cell D. The relationship between its volume and surface area E. The relationship between its volume and length