Question: What measurement unit microbiologists use when they want to measure something really small (like a bacterial cell!)?
Correct Answer To get a micrometre, you multiply the amount of millimeters by a 1000. So, if the answer in millimeters was 3, it would be 3000 in micrometres! A micrometer is one millionth of a meter - very, very small!
Question: What products are, as a general rule, the result of an acid and a base reacting together?
Correct Answer Whenever an acid and base combine, they almost always produce water and a salt. However, water and carbon dioxide are occasionally produced. You have probably heard of the volcano experiment! Well, when you mix baking soda (a base) and vinegar (an acid) together, the end products are water and carbon dioxide. However, it is mostly water and a salt (such as sodium chloride) that are produced in this type of reaction.
Correct Answer The proton has a postive charge, the neutron has no charge, and the electron has a negative charge. The electrons are on the outer orbit of a atom. A covalent bond exists when electrons are shared between atoms. This is the most common form of chemical bonding. All matter is made out of atoms. Chemical elements contain only one type of atom. All the chemicals in a cell are made out of atoms, so atoms must be VERY, VERY tiny indeed!
Question: What gas plants contribute to the earth's atmosphere?
Correct Answer Plants keep the oxygen content stable by photosynthesis. They release oxygen gas into the atmosphere as a by-product of photosynthesis. Denitrifying bacteria contribute to the vast amount of atmospheric nitrogen in the atmosphere (78% of the earth's atmostphere is nitrogen). Carbon dioxide is needed for photosynthesis, but isn't released into the atmosphere by photosynthetic processes.
Question: What organelle is known as the 'brain' of the cell?
Correct Answer The nucleus controls all the reactions within the cell. The chloroplast is the organelle in plant cells where photosynthesis (where radiant energy from the sun is converted to chemical energy) takes place. It contains pigments known as chlorophyll. Chloroplasts are only found in plant cells. The mitochondria is where respiration occurs. All cells (not just plant cells) contain mitochondria. All cells also have a cell-membrane. This selectively allows some materials to pass, and not others, such as starches.
Question: What two elements common table salt is made out of?
Correct Answer Table salt (sodium chloride) is made out of the elements sodium and chlorine. It is made up of one atom of each. Its chemical formula is NaCl. A little salt is needed for all human beings, but too much salt can lead to problems, like high-blood pressure.
Question: A _______ beam is one whose rays remain the same distance apart.
Correct Answer A parallel beam is one in which the light rays always remain the same distance apart. A convergent beam is one in which the light rays slowly converge (come close together and finally meet) as the beam progresses. A divergent beam is one in which the light rays slowly diverge (go far apart) as the beam progresses.