The age of the Earth is estimated at 4.6 billion years. When are the first unicellular organisms thought to have evolved on Earth?
What will be an ideal response?
3.2 to 3.4 billion years ago
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What is the function of lignin in a plant cell?
a. area for gas exchange b. growth c. support d. water conservation
________ lowers blood sugar levels; ________ raises it
Fill in the blank(s) with correct word
The energy of wavelengths that appear ________ is LEAST useful to photosynthesis
A) red B) green C) blue D) orange
Which examples would be considered different species under the biological species concept? Check all that apply.
_____ Two bear species are able to breed in zoos, but have separate ranges in nature. _____ Two skunk species look morphologically similar, but are unable to interbreed. _____ Two snake species look different, but often form fertile hybrids. _____ Two plant species with no gene flow between them. _____ Two tree species have different leaf shapes, but form hybrids in their overlapping ranges. Clarify Question · What is the key concept addressed by the question? · What type of thinking is required? Gather Content · What do you already know about the biological species concept? 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?