The graph below shows the extinction rates for different periods of Earth's history. What is the best estimate for the background extinction rate given these data?

a. 14–20 families per million years c. 2–5 families per million years
b. 8–12 families per million years d. 2–20 families per million years


C

Biology & Microbiology

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A sporic life cycle is NOT characteristic of which of the following groups?

A. ginkgos B. angiosperms C. mosses D. conifers E. charophyceans

Biology & Microbiology

If you examined a cross section of a woody stem under the microscope and located the vascular cambium, the tissues on the inside of the vascular cambium ring (towards the center of the stem) would be  

A.  xylem (primary and secondary). B.  xylem (only primary). C.  phloem (primary and secondary). D.  phloem (only secondary). E.  phelloderm. Clarify Question · What is the key concept addressed by the question? · What type of thinking is required? · What key words does the question contain and what do they mean? Gather Content · What do you already know about the different tissues in a woody stem? How does it relate to the question? Consider Possibilities · What other information is related to the question? Which information is most useful? Choose Answer · Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? Reflect on Process · Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?

Biology & Microbiology

The number of proteins produced by the human genome is significantly less than the number of genes

it contains. Indicate whether the statement is true or false.

Biology & Microbiology

What is an X-linked inheritance pattern? Use a specific example to explain the role of the father and mother in this

unique inheritance pattern and note the differential impact on male and female offspring. What will be an ideal response?

Biology & Microbiology