The correct answer is A, parathyroid gland.
The parathyroid hormone is secreted by the parathyroid gland which <span>inhibits osteoblasts, stimulates osteoclasts,</span> reduces the calcium output by the kidneys and promotes absorption of the calcium by the small intestines. Calcitonin, secreted by the thyroid gland, also works to a similar effect.
First, he should measure how long it takes for the liquid to become clear if X and Y are mixed together. Then, he should measure how long it takes if he also adds substance A to X and Y. He will find out if substance A is a catalyst.
Photosystems 1 and 2 are here
B. Using fewer fossil fuels, such as gasoline for a car, reduces the emission of harmful pollutants into the air
I. Each carbon atom can form single bonds with up to four other carbon atoms. II. Each carbon atom can form double bonds with up to two other carbon atoms. III. Carbon atoms can join together to form chains or rings. IV. A single molecule of some compounds can contain thousands of carbon atoms.
Answer:
All the given choices
Explanation:
Carbon is a very interesting element which is the backbone of most organic compounds.
Organic compounds are made up of carbon. Carbon forms a wide range of compound due to the following properties;
- An atom of carbon has 4 valence electrons and can bond with 4 other carbon.
- Carbon can form single, double and triple covalent bonds.
- They can join together to form rings or chains.
