Why isn't the endometrium shed during a pregnancy?
What will be an ideal response?
The endometrium requires both estrogens and progesterone to be maintained. During a normal menstrual cycle, these two hormones participate in a negative feedback loop that stops the release of the gonadotropins FSH and LH, which in turn stops the production of estrogens and progesterone. During a pregnancy, this feedback loop is bypassed. The chorion, and later its mature form, the placenta, produce a gonadotropin that directs continued production of estrogens and progesterone throughout the pregnancy.
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Metabolic rate can be measured indirectly by measuring consumption of what substance?
A. water B. carbon dioxide C. oxygen D. insulin E. None of these answers are correct.
Select that statement that reflects evidence that directly supports the endosymbiotic theory.
A. Lysosomes contain their own DNA in the form of plasmids. B. The electron transport system is located in the cell membrane in bacteria, while in eukaryotes it is located in the mitochondrial cristae. C. Enzymes for photosynthesis are found embedded in membranes of the Golgi apparatus. D. Glycolysis occurs in the cytoplasm of bacterial cells.
Eating food contaminated with ________ may result in meningitis in at-risk persons
A) Mycoplasma hominis B) Staphylococcus aureus C) Listeria monocytogenes D) Clostridium perfringens E) Enterococcus faecalis
If a pedigree of several generations shows only females affected by a particular trait, it cannot be a(n) ____ trait
a. autosomal recessive
b. autosomal dominant
c. Y-linked
d. X-linked recessive
e. X-linked dominant