AP Biology : Systems Physiology

Study concepts, example questions & explanations for AP Biology

varsity tutors app store varsity tutors android store

Example Questions

Example Question #2 : Understanding Other Immune System Components

What is the most likely mechanism a virus could use to evade the immune system that causes periodic outbreaks in an individual over a long period of time?

Possible Answers:

The virus is continually evolving and manages to vary its antigenic signature so that it can evade detection

The virus manages to attack immune cells needed to control the infection

The virus is actively causing infected cells to secrete factors that suppress the immune system

The virus remains dormant until a stimulus, such as stress or infection with another pathogen, reactivates the virus 

Correct answer:

The virus remains dormant until a stimulus, such as stress or infection with another pathogen, reactivates the virus 

Explanation:

Some viruses evade the immune system using a mechanism known as latency. The virus essentially becomes dormant, usually in cells such as neurons that have few major histocompatibility (MHC) class I molecules. The combination of limited to no active viral replication combined with residence in cells with few MHC lass I molecules allows the virus to evade routine immune monitoring.

When conditions arise, such as fever due to infection caused by another pathogen or emotional stress, the virus can becomes reactivated and can result in an outbreak.

Example Question #222 : Systems Physiology

Which of the following statements is a commonality between T-cell receptors and B-cell receptors?

Possible Answers:

Both receptors are able to bind to intact antigens

Both receptors consist of both heavy chains and two light chains to form the antigen binding domain 

Both receptors have variable regions that form an antigen binding site

Both receptors recognize antigens in conjunction with major histocompatibility complex (MHC) proteins

Correct answer:

Both receptors have variable regions that form an antigen binding site

Explanation:

T-cells generally serve to recognize antigens and escort them to B-cells to elicit a response (helper T-cells) or to recognize antibodies bound to infected cells (cytotoxic T-cells). B-cells, in contrast, will directly secrete antibodies against the antigen after binding of the antigen at the membrane.

Both types of cells have receptors that can bind to antigens, allowing for recognition and communication. Other commonalities include the presence of a transmembrane domain and the presence of a variable region, which will allow for specificity in antigen binding.

The similarities are mainly structural, and the receptors have many functional differences. T-cell receptors will only bind fragments of antigens, while B-cell receptors will bind full molecules. Only T-cell receptors will interact with major histocompatibility complexes (MHC). Though the structure of both receptors types is determined by peptide chains, B-cells use heavy and light chains, while T-cells use alpha and beta chains.

Example Question #5 : Understanding Other Immune System Components

The spleen is an organ of the __________.

Possible Answers:

circulatory system

immune system

digestive system

respiratory system

Correct answer:

immune system

Explanation:

The spleen plays a key role in the immune system as one of the blood filtration centers of the body. It is also involved as a lymphatic organ, allowing filtrates from the blood to be distributed to the body via lymph.

Example Question #223 : Systems Physiology

Which cells of the immune system are largely responsible for phagocytosis?

Possible Answers:

Macrophages

T helper cells

Antibodies

B cells

Correct answer:

Macrophages

Explanation:

Macrophages and neutrophils are the major cells of the immune system responsible for phagocytosis. Phagocytosis means ingestion of material. Therefore these cells work as "garbage collectors" within the body. Cells destined for destruction are tagged for phagocytosis by special molecules.

Example Question #1 : Reproductive System

Which part of the male reproductive system is responsible for sperm storage and maturation?

Possible Answers:

Epididymis

Vas deferens

Testes

Seminal vesicles

Correct answer:

Epididymis

Explanation:

Sperm cells are stored and mature in the epididymis until they are transported to the urethra through the vas deferens. The testes are the site of sperm production, while the seminal vesicles produce fluids that are later incorporated into semen.

Example Question #2 : Understanding Internal Anatomy

Which of the following glands contribute to the production of semen?

Possible Answers:

All of the other choices are correct

Bulbourethral glands

Seminal vesicles

Prostate gland

Correct answer:

All of the other choices are correct

Explanation:

The seminal vesicles secrete seminal fluid to promote and nourish sperm as they are released. The bulbourethral glands secrete a component of seminal fluid, while the prostate gland secretes alkaline fluid.

Example Question #1 : Understanding Internal Anatomy

Which of the following is responsible for the production of germ cells?

Possible Answers:

Fallopian tubes

Ovaries

Endometrium

Uterus

Correct answer:

Ovaries

Explanation:

"Germ cells" is simply another term for gametes, and thus refers to either sperm or ovum.

Ovum are produced in the ovaries. After production, the fallopian tubes propel ovum to the uterus using the movement of cilia. The endometrium is the lining of the uterus, and allows for implantation of a fertilized ovum.

Example Question #1 : Reproductive Anatomy

Where does fertilization typically take place in the female?

Possible Answers:

Uterus

Ovary

Cervix

Fallopian tubes

Correct answer:

Fallopian tubes

Explanation:

In the majority of cases, fertilization occurs in the fallopian tubes of the female. The egg is released from the ovary and travels into the fallopian tube during ovulation. Sperm travel to the fallopian tube to fertilize the egg, creating a zygote. The zygote begins to divide, forming a blastocyst before it reaches the uterus where it becomes embedded in the endometrium via the process of implantation. Certain pregnancy complications can arise if the blastocyst implants while still in the fallopian tube, resulting in ectopic pregnancy.

Example Question #5 : Understanding Internal Anatomy

What is the site of sperm maturation and storage in males?

Possible Answers:

Epididymis

Prostate

Seminiferous tubules

Vas deferens

Correct answer:

Epididymis

Explanation:

Sperm is created in the seminiferous tubules of the testes. It is then transported to the epididymis, where it will mature and be stored prior to ejaculation.

Example Question #1 : Understanding Internal Anatomy

The epididymis, vas deferens, and urethra are a series of ducts found in which body system?

Possible Answers:

Integumentary

Lymphatic

Male reproductive

Endocrine

Digestive

Correct answer:

Male reproductive

Explanation:

The male reproductive system consists of a series of ducts, which includes the epididymis, vas deferens, and urethra. The epididymis is a coiled tube attached to the testis, which receives sperm from the seminiferous tubules. The vas deferens connects the epididymis with the urethra, which in turn conducts sperm to the tip of the penis. 

Learning Tools by Varsity Tutors