Which of the following nucleotides is only found in RNA?

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.

The vermiform appendix is a small, finger-like projection that extends from the cecum, which is the first part of the large intestine.

The parathyroid hormone (PTH) from the parathyroid glands is important in serum calcium regulation. It increases blood calcium levels by stimulating osteoclasts to break down bone and release calcium into the bloodstream. PTH also enhances the absorption of calcium from the intestines and the kidneys.

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.

A chlorine molecule contains the fewest covalent bonds among the options provided. It consists of two chlorine atoms bonded together by a single covalent bond. Compared with the other options, ammonia has three covalent bonds, methane has 4 while water has 2.

Concentration of H+ in the solution = 10 −1 M

pH= -log(10 −1)

pH= -(-1)

=1

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

Exocrine glands secrete their products into ducts that carry them to the target organs. In contrast, endocrine glands secrete their products directly into the bloodstream, which carries them to target cells throughout the body.

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

• Potassium is an alkali metal, which tends to lose one electron to form a cation with a \(\pm1\) charge.
• Likely to become a cation.