Which of the following statements are true of the cell membrane? I. composed of proteins and lipids
II. composed of proteins and cellulose
III. located in animal cells
IV. located in plant cells
V. semipermeable
VI. not permeable at all
A.
I, III, IV, and V only
B.
II, III, IV, and VI only
C.
I, IV, and VI only
D.
II, IV, and V only

Which of the following factors would not contribute to allopatric speciation? a) a population becomes geographically isolated from the parent population. b) the separated population is small, and genetic drift occurs. c) the isolated population is exposed to different selection pressures than the ancestral population. d) different mutations begin to distinguish the gene pools of the separated populations. e) gene flow between the two populations is extensive.

(me out over the last several centuries, scientists have made the following broad observations while investigating several branches of the life sciences: -the fossil record shows that different types of organisms have existed at different times in earth's history. -many organisms have similar body structures that seem to be adapted to different ways of living in their environment. -organisms of different species often share similarities in stages of embryonic development. -many species share genetic similarities, and almost all organisms use the same basic building blocks to construct proteins. -often, the extent of two species' similarities can be predicted from their geographic closeness to each other. -a great deal of change has been observed among species that have experienced strong selective pressures through many generations. scientists have carefully considered and rigorously tested the observations listed above. when scientists offer a of these observations, they are making 1.) testable explanation, deductive explanation 2.) scientific interference, scientific law

Dna in the nucleus carries the genetic code for making proteins in ribosomes. the diagram shows a model of dna. which part of the dna molecule codes for the amino acid sequence in the protein? a) sugar b) phosphate c) deoxyribosed) nitrogen bases