During the end-Permian mass extinction:
A. oxygen levels in the deep oceans dropped.
B. global warming occurred as a result of
volcanic eruptions.
C. oceans were acidified as a result of
volcanic eruptions.
D. oxygen levels in the deep oceans dropped
and oceans were acidified as a result of
volcanic eruptions.
E. all of the answer options are correct.
E
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Amniocentesis is _____
a. a surgical means of repairing deformities b. a form of chemotherapy that modifies or inhibits gene expression or the function of gene products c. used in prenatal diagnosis to detect chromosomal mutations and metabolic disorders in embryos
d. a form of gene replacement therapy e. commonly performed on newborns
Treponema pallidum is the bacterium that causes syphilis. The gram-negative spirochete has never been cultured on bacteriological media. Select the statement that most accurately describes this disease-causing microbe.
A. Koch's postulates cannot be fulfilled for this disease. B. There is no satisfactory way to identify the disease without being able to grow it. C. There is no way to perform an epidemiological study on this disease. D. Because the bacterium cannot be grown, there is no way to characterize the organism as to staining features, biochemical test reactions, molecular testing, etc.
Is made up of collagen and calcium-binding proteins, collagen makes up 90% of bone protein. Makes up one third of organic bone matrix, is secreted by osteoblasts. Consists of ground substance and collage fibers, which contribute to high tensile strength and flexibility of bone.
What will be an ideal response?
Four of the following describe a bilaterally symmetrical animal. Which one is the exception?
a. It has left and right sides.
b. It usually displays cephalization.
c. It produces mirror images regardless of the number of "cuts" through the central axis.
d. It usually has a three layer body plan.
e. It can be a deuterostome.