#Question id: 11798
#Unit 6. System Physiology – Plant
Companion cells transport of photosynthetic products from producing cells in mature leaves to the sieve elements in the minor veins of the leaf. There are at least three different types of companion cells in the minor veins of mature, exporting leaves, All three cell types have dense cytoplasm and abundant mitochondria;
#Question id: 12594
#Unit 10. Ecological Principles
Use the following diagram of five islands formed at around the same time near a particular mainland and MacArthur and Wilson's island biogeography principles to answer the following questions.
Which island would likely have the lowest extinction rate?
#Question id: 4535
#Unit 3. Fundamental Processes
The activators bind—and the enhanceosome forms—in a highly cooperative manner, ensuring that all three activators must be present. The following are three ways the regulators might be binding cooperatively:
I- Through direct protein–protein interactions between them
II- By changes in the DNA caused by binding of one protein helping binding of another;
III- By the fact that the activators all interact simultaneously with the coactivator.
#Question id: 18655
#Unit 13. Methods in Biology
#Question id: 24506
#Unit 10. Ecological Principles
the immunological response is short-lived, the infections tend to be persistent by