In the Sea the Nitrogen:phosphorus Ratio

question 14

Multiple Choice

In the sea the nitrogen:phosphorus ratio

• A) Varies greatly between phytoplankton and the water column
• B) Varies strongly between winter and summer
• C) Of phytoplankton resembles that of the water column
• D) Is strictly constant at 1:15

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Definitions:

Haploid

A cell or organism having a single set of chromosomes, characteristic of gametes such as sperm and egg cells in sexually reproducing organisms.

Nuclear Membrane

A double lipid bilayer that encloses the cell's nucleus, separating its contents from the cytoplasm and regulating the passage of materials in and out of the nucleus.

Mitosis

A type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus, typical of ordinary tissue growth.

Contractile Ring

A band of protein fibers that forms in the middle of a cell during cytokinesis, leading to cell division.