The "gray matter of the brain is largely made up of which of the following?

Both prokaryotic and eukaryotic cells have a cell membrane. The cell membrane is a barrier that surrounds the cell and separates its internal environment from the external environment.

Rationale

Atoms are the smallest and most basic units of matter, and they can combine to form molecules. Cells are the basic units of life, and they are made of molecules. Tissues are groups of cells that work together to perform a specific function, such as muscle tissue or nerve tissue. Organs are collections of tissues that form a larger structure.

The pituitary gland produces prolactin, which regulates milk production

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

Rationale

Electrons are subatomic particles that have relatively little mass and are negligible when calculating atomic mass. The atomic number is usually the sum of protons and neutrons in the nucleus of the atom.

ATP is produced by a series of reactions that occur in the mitochondria. The mitochondria have a double membrane structure, with an inner membrane that is folded into cristae. These cristae contain the enzymes and proteins that are involved in the process of cellular respiration, which converts glucose and oxygen into ATP and carbon dioxide.

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.

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 gray matter of the brain primarily consists of neuron cell bodies, along with dendrites, glial cells, and unmyelinated axons. It appears gray because it lacks the white fatty myelin sheath that covers many nerve fibers.

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.