Gases are constantly consumed and produced by cellular and metabolic reactions in most living things, so an efficient system for gas exchange between, ultimately, the interior of the cell(s) and the external environment is required. Small, particularly unicellular organisms, such as bacteria and protozoa, have a high surface-area to volume ratio.
Polyploid. (genetics) an organism or cell having more than twice the haploid number of chromosomes.Of a cell or organism having more than twice the haploid number of chromosomes; a polyploid cell; a polyploid species .Organisms that possess two sets of each chromosome.
Many grass species are polyploid; some species can have more than 10 sets of chromosomes. Polyploidy occurs in some animals, such as goldfish, salmon, and salamanders, but is especially common among ferns and flowering plants, including both wild and cultivated species.Many grass species are polyploid. Polyploids tend to be larger than their diploid counterparts. They have larger cells with increased volume. â¢ Polyploids tend to display semi-sterility or sterility. â¢ Polyploid plants tend to display heightened susceptibility to frost damage and higher resistance to pests and pathogens.