When you are standing upright, what is the primary mechanism that propels blood in your feet back to your inferior vena cava?
A. Contraction of smooth muscle in the walls of the leg veins
B. Contraction of the left ventricle of the heart
C. Recoil of elastic fibers in the walls of the leg veins
D. Contraction of skeletal muscles in your legs
E. The valves in the leg veins alternating between open and closed
Answer: D
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Which of the following is an example of a positive feedback loop?
a. maintaining body temperature b. blood pH levels c. uterine contractions during childbirth d. blood glucose levels
If an individual has his/her gallbladder removed, he/she is typically put on a low-fat diet. Which of the following would explain this recommendation?
A. Bile acids cannot be produced. B. Bile acids cannot be removed from the intestines. C. Bile acids cannot be released following a meal. D. Lipase cannot be released following a meal. E. Lipase cannot be produced.
Seeds are reproductively superior to spores because:a
seeds contain a multicellular young plant. b. only seeds can survive for an extended period of time. c. seeds are used as a food source for humans. d. seeds are protected by a multicellular seed coat. e. seeds contain a young plant and also are protected by a seed coat.
In the figure below, you will find the offspring of two individuals, each with two alleles at two loci
Both parents are heterozygous at locus 1 (Aa) and locus 2 (Bb). All parental haplotypes are in coupling (AB, ab). Which of the color boxes are double heterozygote in repulsion offspring? a. light grey b. medium grey c. dark grey d. B and C e. All of the above