Suppose that a diploid cell contains 8 chromosomes (2 n = 8). How many different combinations in the gametes are possible?

16

Explanation:

A diploid organism that produces gametes will undergo meiosis to do so. Meiosis reduces the chromosomal number in the gametes by half. Hence, each gamete will have 4 chromosomes (haploid,n). Crossing-over will likely occur during the meiotic process leading to recombination in the arrangement of chromosomes in the gametes.

If this occurs, a mathematical expression of 2^n is used to determine the number of possible combinations, where n is the number of chromosomes in the gamete.

Hence, 2^4 = 16 possible combinations of chromosomes in the gamete.

answer: - few nutrients

high pressure

low temperatures

explanation: 1. few nutrients:   open-ocean zone is located way far from the land, which is the main source of the essential nutrients.2. high pressure: pressure increases by 1 atmosphere for every 10 meters increase in depth.3. ample sunlight: a large fraction of the sunlight is reflected back to the atmosphere from the sea surface. 4. varying salinity: below the thermocline, the water is isolated from the atmosphere so the salinity remains stable over the year.5. low temperatures:   the temperature of open-ocean zone ranges from a low of -2°c to an average of 17°c