What happens when pollen from one species lands on the stigma of a flower from another species?
a. The pollen tube typically forms and grows to the ovary, but then stops.
b. The pollen tube typically forms, but the sperm are killed.
c. The pollen tube typically does not develop.
d. The pollen tube typically forms, but the sperm cannot penetrate the egg.
Answer: c. The pollen tube typically does not develop.
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You dissect the brain of a mutant mouse and find that parts of the "white matter" look gray. What is a likely cause?
A. defects in myelination B. peripheral nerve damage C. oversized dendrites D. excess myelination E. excess neuronal proliferation Clarify Question · What is the key concept addressed by the question? · What type of thinking is required? · What key words does the question contain? Gather Content/Choose Answer · What do you already know about white matter? How does it relate to the question? Consider Alternatives · What other information is related to the question? 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?
The processes listed below represent major chemical pathways in
photosynthesis. Respond to statements 80–84 with reference to these five processes. a. light-dependent reactions b. chemosynthetic reactions c. carbon dioxide fixation d. Calvin-Benson cycle e. C4 pathway D 80. This leads to the formation of a glucose-6-phosphate from two molecules of phosphoglyceraldehyde. M 81. In this process carbon dioxide is incorporated first into an unstable intermediate compound and then into phosphoglycerate. E 82. This yields NADPH as well as ATP. M 83. This is a carbon-fixing system that precedes the Calvin-Benson cycle in some plants. M 84. PGAL molecules are formed from the reaction of PGA molecules with ATP and NADPH in this pathway.
DNA strands can be pulled apart by adding heat and "melting" the double-stranded DNA. The temperature required to melt a region of DNA changes based on the base-pair composition
Based on the structure of the A-T and C-G bonds in the accompanying figure, which bonds would require more energy (heat) to break them? How might this help you predict which regions of the DNA helix may be the most stable and harder to break apart?
Gs? activates ________
Fill in the blank with correct word.