Which of the following organelles is the site of intracellular digestion?

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.

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

This means that a hypothesis is considered valid until it is disproved by experimental evidence. However, even if a hypothesis has not been falsified, it is still considered provisional and subject to further testing and scrutiny.

The renal vein drains deoxygenated blood from the kidneys to the inferior vena cava.

This is because when a proton is emitted from an atom, the atomic mass decreases by one unit, and the atomic number decreases by one unit. The atomic mass is the sum of protons and neutrons in the nucleus, and the atomic number is the number of protons in the nucleus. Therefore, if a proton is lost, both numbers decrease by one.

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

The experienced mountain climber is replicating the conditions of the past expedition to understand why that earlier attempt was unsuccessful.

Objects A and B have the same and are subjected to the same gravitational pull. However, object B falls faster than A. This is due to a greater air resistance for A than B.

Rationale

Chromatin refers to a complex of DNA and proteins in human cells. This material is packaged by histones to make up the chromosomes. The chromosomes then contain genetic information that is heritable.

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.