The membranous myelin sheath that surrounds and electrically insulates many nerve cell axons is particularly rich in

#Question id: 4963

#Unit 11. Evolution and Behavior

Which free-living cells were the earliest contributors to the formation of Earthʹs oxidizing atmosphere?

#Question id: 1388

#Unit 4. Cell Communication and Cell Signaling

When Lucifer yellow, a small dye, is injected into a neuron of the retina, neighboring neurons become rapidly labeled. If the retina is incubated in dopamine prior to Lucifer yellow injection, only the injected neuron becomes labeled. These findings suggest which of the following?

I. Neurons of the retina communicate via gap junctions.

II. Dopamine is transferred between cells via gap junctions.

III. Dopamine decreases the permeability of gap junctions.

#Question id: 2954

#Unit 2. Cellular Organization

Cyclin concentrations are highest during which periods of the cell cycle?

#Question id: 5714

#Unit 8. Inheritance Biology

Homologous chromosomes pair in prophase I as a following way, if crossing over occur between P and Q gene of homologous chromosome?

Which of the following consequence of above abnormality?

A. Dicentric chromosome visible at anaphase I

B. Results in formation of acentric chromatid

C. Recombinant gamete unable to produced viable progeny due to missing of many gene

D. Resulting recombinant gamete become aneuploid 

#Question id: 26434

#Unit 3. Fundamental Processes