Do mutations occur because the organism needs a new trait?

Fish in a marine environment must maintain a relatively constant ion concentration in their tissues and blood. How do the chloride cells in the gills aid fish in the removal of excess ions? A.

Cells divide differentiate or die. What is differentiation

Using context clues, what does predecessors mean as it is used in the first paragraph

Monkeys and humans share many of the same DNA sequences and have similar proteins, indicating that a ... the two groups belong to the same specie b ... the two groups share a relatively recent common ancestor c ...

List at least 5 diseases/disorders that have been attributed to older "dumps ". ap environmental science

Explain briefly why there is a limitation on how big a cell can be. Include in your explanation the relationship between a cell's size and its surface area and how this affects what the cell can do.

Which effect is most likely caused by nondisjunction during meiosis? A. an extra chromosome B. an increase in nuclei C. increased survival benefits from traits D. only two types of nitrogenous bases

A segment of dna that codes for rna and a protein is a

For older adults and previously inactive individuals, exercise intensity should fall closer to what percentage of the maximal heart rate?

Colleen has been advised by her physician to avoid taking high-dose supplements of certain vitamins because they can accumulate to toxic levels in her body. which vitamins?