Which lineage of Echinoderms is made up of about 950 species of sea urchins and sand dollars, which have their ossicles fused into solid tests that restrict flexibility but provide excellent protection?
a. Holothuroidea
b. Crinoidea
c. Asteroidea
d. Echinoidea
Answer: d. Echinoidea
Biology & Microbiology
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The nutrition of some plants depends on a mutually beneficial association between a root and a fungus. The association is known as a _____
a. root nodule c. root hair b. mycorrhiza d. root hypha
Biology & Microbiology
This animal has a pseudocoelom, is
unsegmented, a cuticle, and no circulatory system. This animal is ___.
a. a roundworm b. an earthworm c. a flatworm d. a leech e. more than one of these
Biology & Microbiology
Which type of stem cell gives rise to red and white blood cells?
a. endothelial b. epithelial c. hematopoietic d. mesenchymal
Biology & Microbiology
The scientific method starts with a(n)
A) hypothesis. B) proposal. C) question. D) observation. E) prediction.
Biology & Microbiology