What are two things scientists still do not understand about adult stem cells?

Which planes when passed through the body would result in 2 sections with each section containing a piece of the heart and a piece pf each lung?

When activity and stimulation decrease, overwhelming drowsiness occurs almost instantaneously.?

A diseased cell is no longer able to produce proteins. Which cell structure is most likely malfunctioning? a. nucleus b. cytoplasm c. ribosome d. mitochondrion

fish are not able to regulate their body temperature by creating heat. how could a fish adjust its body temperature if it were too warm

Crossing over is often reduced around centromeric regions of chromosomes. If you were trying to construct a genetic map of two linked marker loci in this region, what result might you obtain and why?

What kind of bonds form between the oxygen atoms of one water molecule and the hydrogen atoms of another water molecule

Salamanders brought into a new ecosystem that is colder than its all ecosystem the salamander cannot survive in the cold temperature in days which is the best way to describe a salamander in the new ecosystem

Trace a drop of blood from the left atrium to the left hallucinating and back to the right atrium

Besides the ability of some cancer cells to divide uncontrollably, what else could logically result in a tumor?

Which of the following is an abiotic factor you might find in a desert