Which of the following organs removes nitrogenous waste from the body?

The digestive system breaks down complex food substances into small and less complex absorbable compounds. Proteins, for instance, are broken down to constituent amino acids through a digestion process that combines mastication and enzymatic breakdown.

A gene is a segment of DNA that codes for a specific protein or polypeptide.

Helper T cells are important cells that stimulate the action of other immune cells. For instance, they not only help activate B cells to secrete antibodies and macrophages to destroy ingested microbes, but they also help activate cytotoxic T cells to kill infected target cells.

The inner lining of the uterus is the source of blood and mucosal tissue that is shed during menstruation.

A spectrophotometer is an instrument that measures the intensity of light absorbed after it passes through a sample solution. With the spectrophotometer, the concentration of a chemical substance can be determined by measuring the intensity of light detected.

Rationale

Atoms are the smallest and most basic units of matter, and they can combine to form molecules. Cells are the basic units of life, and they are made of molecules. Tissues are groups of cells that work together to perform a specific function, such as muscle tissue or nerve tissue. Organs are collections of tissues that form a larger structure.

a. Water boils to produce steam at 100°C - This is a phase change (from liquid to gas) and not a chemical reaction of water.

b. Water dissolves sugar - This is a physical change, not a chemical reaction of water.

c. Water produces gas with sodium metal - This reaction involves the chemical reaction of water with sodium metal to produce hydrogen gas.

d. Water and oil separate when combined - This is a physical separation, not a chemical reaction of water.

Conducting the experiment with half the women taking water and the other half taking an energy drink creates a study and experimental group, which can allow for comparison and conclusion. The researchers can compare the effects of the energy drink directly with a baseline, and this helps to establish a cause-and-effect relationship and provides stronger evidence to support their conclusion.

Browning of the apple surface is due to the action of the enzyme polyphenol oxidase. Lemon juice is acidic and lowers the pH of the apple's surface. This inactivates the enzyme polyphenol oxidase, which works best at a neutral pH. This in turn reduces the browning action on the apple.

Rationale

Chromatin refers to a complex of DNA and proteins in human cells. This material is packaged by histones to make up the chromosomes. The chromosomes then contain genetic information that is heritable.