Hello! It is necessary for a scientist to do research prior to an experiment so they have more background on what they are going to examine. I hope this heps and feel free to rate my answer :)
Answer:
Option (3).
Explanation:
Teratogens may be defined as the chemicals that can cause birth defects in the fetus. Substances like alcohol, lead and nicotine acts as the main agents of tertaogens.
Shamona is drinking water that contains high level of lead. The element lead is harmful for the fetus. Even the small concentration of lead is enough to cause birth defects. The lead exposure can cause the abnormal development of brain and damages the brain of fetus. The fetus has low birth weight also.
Thus, the correct answer is option (3).
Answer:
tissue is a group of cells that have a similar function.
A gas is given off when two substances are mixed.
<u>physical change: A copper rod is hammered into a thin sheet. </u>
A solid forms when two clear liquids are mixed.
A matchstick changes color when it burns.
explanation
a physicals change vs chemical
physical change is like cutting, changing shape etc, it the molecules that make it and the chemicals of it stay same
chemical change when it chemically changed such as cooking meat
Correct answer: A). Chemical
The light-dependent reaction of photosynthesis occurs in the thylakoid membrane, chlorophyll absorbs the energy from the sunlight. After that, the light energy is converted into chemical energy by using water. Then the lower energy NADP+ get high energy electrons and protons and get converted into NADPH and ATP.