Which of the following statements about the structure of microtubules is false?
(a) Microtubules are built from protofilaments that come together to make a hollow structure.
(b) The two ends of a protofilament are chemically distinct, with ?-tubulin exposed at one end and ?-tubulin exposed at the other end.
(c) Within a microtubule, all protofilaments are arranged in the same orientation, giving the microtubule structural polarity.
(d) ?-Tubulin and ?-tubulin are covalently bound to make the tubulin dimer that then assembles into protofilaments.
(d) ?-Tubulin and ?-tubulin bind with each other through noncovalent interactions.
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Which type of homology does this typify?
When humans are developing, in utero, they have characteristics that are not found in the fully developed infant. Gill slits are one example of these characteristics. A. Developmental. B. Structural. C. Vestigal. D. Molecular. E. Both developmental and vestigal.
Heritability of a trait can change because
A) genes mutate. B) the environment can change. C) a person can consciously change her or his heritability. D) the heritability in a family changes with the number of children.
is simple diffusion carrier or non carrier mediated
What will be an ideal response?
Coordinating the body's responses to changes to the external environment is primarily the function of the __________ system.
Fill in the blank(s) with the appropriate word(s)