These pills inhibit ovulation processes as well as implantation. Therefore, women can prevent unplanned pregnancy by using these pills
Answer: When the plant has enough water in its cells the guard cells swell up and open the stomata. When the plant isn't getting enough water the guard cells can't swell and the stomata stay closed, so the plant doen's lose water. But if the stomata are closed photosynthesis can't happen and eventually the plant might starve.
Explanation:
Answer:
The correct answer is b. He determined that DNA contains four nitrogenous bases.
Explanation:
Levene was an American biochemist who studied the structure of DNA in the early 1900s and in 1920 he found that DNA consists of four nitrogenous bases that are Adenine, Guanine, Thymine, Cytosine.
He also found deoxyribose sugar and phosphate group and said that nucleotide is the basic unit of DNA which contains a ribose sugar with attached nitrogenous base and phosphate group.
He also concludes that an equal amount of adenine, guanine, thymine, and cytosine makes the DNA which is now known as tetranucleotide hypothesis. So the correct answer is b. He determined that DNA contains four nitrogenous bases.
Answer and Explanation:
Mitosis is the type of division that occurs in the general body cells resulting in growth while meiosis is the process that occurs during the formation of sex cells. Mitosis results in two daughter that are identical to one another and to the parent cell. In meisosis there is crossing over during prophase I.