#Question id: 12131
#Unit 10. Ecological Principles
Use the following diagram of a hypothetical food web to answer the following questions. The arrows represent the transfer of food energy between the various trophic levels.
Which letter represents an organism that could be a producer?
#Question id: 32395
#Unit 1. Molecules and their Interaction Relevant to Biology
#Question id: 5659
#Unit 5. Developmental Biology
Following are the statements related to mammalian chaemotaxis .
A. During chaemotaxis, the oocyte and its accompanying cumulus cells secrete molecules that attract only uncapacitated sperm toward the egg during the last stages of sperm migration.
B. These chaemotactic compound are hormone progesterone, which is made by the cumulus cells.
C. Progesterone has been shown to bind to a receptor that activates Ca2+ channels in the cell membrane of the sperm tail, leading to sperm hyperactivity and provides directional cue.
D. Cumulus cells also secrete a substance, CRISP1, that attracts sperm and hyperactivates them through CatSper channels similar as in sea urchins.
Which of the following statement is incorrect?
#Question id: 1911
#Unit 4. Cell Communication and Cell Signaling
Which of the following does NOT minimize allogeneic graft rejection?
#Question id: 28725
#Unit 2. Cellular Organization
Soluble ER-resident proteins contain which sorting signal that allows them to be retrieved?