BIO 1409 Test 4

Which structure in the brain connects the two hemispheres?

Corpus Callosum

____ are foreign molecules that stimulate the production of ____.

Antigens, antibodies

White blood cells are produced

from bone marrow stem cells.

What is the first stage in human development in which there are three germ layers?

gastrula

Which stage in embryonic development is the embryo a hollow ball?

gastrula

The endocrine system consists of 2 main components: ____ which have cells that produce and secrete ____.

glands, hormones

These cells of the immune system produce cytokines that increase phagocytosis and stimulate B Cells to produce antibodies.

helper T cells.

A primary antigen-presenting cell, a cell that presents an antigen that activates a helper T cell, is a

macrophage

A person who is an organ transplant recipient must take immune suppressant drugs for the rest of his/her life because the donated organ will have a different ____.

major histocompatability complex

A Node of Ranvier is a break in the _____ .

myelin sheath

What cells in nervous tissue carry electrical signals?

neurons

When an action potential reaches the end of the axon, what chemical carries the signal to a neighboring dendrite?

neurotransmitter

What is able to pass across the placenta between the embryo/fetus during pregnancy?

nutrients fetal waste products oxygen carbon dioxide carbon monoxide nicotine alcohol illegal street drugs small viruses

One hormone functions both in causing uterine contractions during labor and in the production of milk. What is that hormone?

oxytocin

Which of the following hormones is released by the posterior pituitary gland?

oxytocin

The endocrine gland that controls homeostasis in terms of blood glucose levels is the

pancreas

Which can be a target of autoimmune disease but is not considered to be a major part of the immune system itself?

pancreas

Once a stressful situation is over and we calm down and can once again do things like digest our food it is because the ______ nervous system is operating.

parasympathetic

Physical and chemical barriers that form the first line of innate defense include

the acidity of the stomach. tear fluid from the eye. an unpunctured skin. mucus and cilia of the respiratory tract.

A preparation that "teaches" the immune system to recognize a disease-causing agent without actually causing disease is termed a(n)

vaccination

What structure of the neuron both increases the speed of a nerve impulse and allows the neuron to function with less energy cost?

Nodes of Ranvier

Which of these methods of reproduction is an example of sexual reproduction?

None of these is an example of sexual reproduction. fission budding fragmentation parthenogenesis

Most nerve cells are separated by space (called a gap, or synapse). How does a nerve impulse travel across this space?

One neuron secretes a chemical that stimulates the next neuron.

Slowed nerve impulse transmission results from damage to

the myelin sheath.

A human embryo may have the chromosomes XX or XY. Which of these is a female?

XX

A molecule that stimulates an immune system reaction by B cells and T cells is termed a(n)

antigen

When a nerve impulse travels from one neuron to another it follows this path:

axon, synapse, dendrite

Bacteria reproduce by _____ .

binary fission

The placenta is part of the _____ body.

both the mother's and the fetus's

Corals and hydras can reproduce by producing an outgrowth which becomes a new individual. This form of reproduction is known as _____ .

budding

Non-mammals, such as birds and reptiles, have a common body opening, called a _____ for the digestive, excretory and reproductive systems

cloaca

In a process called _____, an army of plasma cells and memory cells are produced from properly stimulated B cells.

clonal selection

When activated, __________ trigger(s) a chain reaction that punctures bacterial cell membranes.

complement proteins

Which part of a neuron receives the nerve impulse from another neuron?

dendrite

Which germ layer develops into the central nervous system and the epidermis?

ectoderm

Which of these means of reproduction uses a placenta?

viviparity