The appearance of __________ marks the onset of
gastrulation in humans.
a. a notochord
b. the primitive streak
c. mesoderm
d. neural folds
e. somites
Answer: b
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Over a lifetime about how many primary oocytes move through the ovarian cycle?
a. 300 b. 1000 c. 20,000 d. 200,000 e. 2,000,000
When the trunk or limb of a tree provides the substrate on which an epiphytic orchid grows, the arrangement benefits the orchid, which gets nutrients from the air and moisture from aerial roots, while the tree is unaffected
The relationship is referred to as A) amensalism. B) commensalism. C) competition. D) parasitoidism.
The smooth ER is the primary site for the synthesis of phospholipids and cholesterol needed to make ____
a. DNA b. ATP c. ribosomes d. hormones e. cell membranes
Which of the following observations were an outcome of studies by David Tilman and coworkers at Cedar Creek, Minnesota on ecosystem stability? (Check all that apply.)A) Plots with more species showed less year-to-year variation in biomass.B) Species-rich plots were less affected by drought than species-poor plots.C) Over-yielding was observed in more recent work at Cedar Creek.D) Nitrogen uptake and total biomass produced were negatively correlated to species richness.E) More diverse plots were less susceptible to invasion by new species.
What will be an ideal response?