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

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

The hip joint is an example of a ball-and-socket joint. The hip joint is formed by the articulation of the head of the femur with the acetabulum of the pelvis. The rounded head of the femur (ball) fits into the cup-shaped acetabulum (socket), allowing for a wide range of motion in multiple planes.

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

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.

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.

Helper T cells are important cells that stimulate the action of other immune cells. For instance, they not only help activate B cells to secrete antibodies and macrophages to destroy ingested microbes, but they also help activate cytotoxic T cells to kill infected target cells.

The pH scale is logarithmic, indicating that each whole number change on the pH scale represents a tenfold change in acidity or alkalinity. Therefore, a substance with a pH of 3 is 10 times more acidic than a substance with a pH of 4.

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.

Cardiac muscles have intercalated discs that enable them to contract in a coordinated manner. Skeletal muscles do not have intercalated discs, as their contraction is under voluntary control and does not require the same level of synchronization seen in the involuntary contraction of cardiac muscle.

Psoriasis is a chronic skin condition that causes red, scaly patches on the skin. It is not contagious, and it is not caused by any microorganism. It is believed to be an autoimmune disorder where the immune system attacks healthy skin cells.