Potassium channels close slowly, thus allowing too much potassium out of the cell

Sodium channels close slowly, thus allowing too much sodium into the cell

Sodium channels close quickly, not allowing enough sodium into the cell

Potassium channels close quickly, not allowing enough potassium out of the cell

Hyperpolarization only occurs in cells that are not able to be depolarized

All of these

Cell polarization

Gap junctions between embryoblasts

Compaction of trophoblasts

After fertilization

During the entirety of cleavage

During gastrulation

Only after implantation

Convergence and invagination

Convergence

Invagination

Neither convergence nor invagination

B-lymphocytes, usually with input from helper T-lymphocytes

Helper T-lymphocytes, usually with input from B-lymphocytes

Natural killer cells

Dendritic cells

Schwann cells

Glial cells

Astrocytes

Ependymal cells

Myocytes

When menstrual periods begin in human females

When menstrual periods stop in human females

Implantation of the embryo in human females

Contractions preceding vaginal delivery

Initiation of the acrosomal reaction

Loss of certain membrane proteins to facilitate binding to the oocyte

Increase in intracellular calcium levels

Change in sperm tail beating pattern

They are eukaryotic somatic cells

Female gametocytes are called oocytes

Gametocytes can divide by mitosis into other gametocytes

Male gametocytes are called spermatocytes

Secretion of molecules that diffuse locally and trigger a response on neighboring cells

Secretion of molecules that diffuse into the bloodstream and trigger a response in target cells anywhere in the body

Secretion of molecules that diffuse locally and trigger a response in the same cells that secreted them

Secretion of neurotransmitters that diffuse across synapses and trigger a response in cells of target tissues (neurons, muscles, and glands)