Human Biology: Immune System, Reproduction, and Cardiovascular Health

Vaccines and the Immune System

1. Vaccines introduce weakened or dead pathogens to stimulate the immune system. This prepares the body to fight future invasions by these microbes.

Vasectomy: Blocking Sperm Transport

2. In a vasectomy, the structure that is closed or blocked to prevent sperm from traveling from the testes to the urethra is the vas deferens.

Non-Specific Immune Responses

3. Sweat and skin secretions kill or limit the growth of many types of microbes. This control of microbes is an example of a non-specific immune response against infection.

The Amniotic Sac in Pregnancy

4. The fluid-filled structure in which the embryo is protected during pregnancy is called the amniotic sac.

Opportunistic Infections

5. Pathogens that cause opportunistic infections rarely overcome a healthy immune system.

Fraternal Twins: Fertilization of Two Eggs

6. The event that can result in the birth of fraternal twins is the penetration of two eggs by two sperm.

Antigens and Immune System Recognition

7. Antigens are protein markers that are important because they help the immune system recognize foreign cells.

Gametogenesis: Location

8. Gametogenesis occurs within structures E and G (likely referring to ovaries and testes in a diagram).

Cellular and Humoral Immunity: Acquired Immunity

9. Cellular immunity and humoral immunity are similar because they both produce acquired immunity.

Blood Flow Through the Heart

10. In a diagram of the human heart with arrows indicating blood flow, the last chamber that blood passes through before exiting the heart to circulate around the body is likely the left ventricle (represented by the number 2 in the original text).

The Body's First Line of Defense

11. Which of the following does not constitute a barrier part of the body's first line of defense? B-cells that produce antibodies.

Diabetes and Blood Viscosity

12. Diabetics often have increased levels of sugar in their blood. This can lead to increased blood viscosity, which may affect blood flow.

Atherosclerosis: Impact on Blood Pressure and Flow

13. In atherosclerosis, plaque collects on the walls of arteries. This would increase blood pressure and decrease blood flow.

Pollen and Allergic Responses

14. Pollen grains often stimulate an allergic response that produces antibodies.

Arteriole Identification

15. In a diagram, the structure that represents an arteriole is likely labeled B.

Second Trimester of Pregnancy: Brain Growth

16. During the second trimester of pregnancy, the brain grows rapidly.

Highest Oxygen Concentration in Blood

17. The structure that contains blood with the highest oxygen concentration is likely the pulmonary vein (represented by the number 2 in the original text).

HIV and Opportunistic Infections

18. Individuals with HIV sometimes contract a rare pneumonia infection that usually does not affect the rest of the population because they are unable to fight off these pneumonia-causing organisms due to a weakened immune system.

Blood Clots: Effects on Blood Flow

19. The most likely effect of a blood clot on blood flow through the cardiovascular system is that it will block blood flow, preventing oxygen from reaching tissue in a certain area.

Ovulation

20. In a diagram of the female reproductive system, the event occurring at point D is likely ovulation.

Antibiotics: Bacteria vs. Viruses

21. Human diseases caused by bacteria and diseases caused by viruses react differently to antibiotics: bacterial diseases respond to antibiotics, while viral diseases do not.

Hominid Evolution and the Frontal Lobe

22. Hominid evolution trends include larger brain size, smaller jaws, and advancements in communication and tools. The development of the frontal lobe led to an increase in logical thinking and reasoning.

Specific Immunity

23. A diagram representing an immune response in the human body likely illustrates specific immunity.

The Brain: Feeling Pain and Pressure

24. The part of the brain responsible for feeling pain and pressure is the parietal lobe (likely represented by the number 1 in the original text).

Maternal and Embryonic Tissues

25. In a diagram, the structure formed from both maternal and embryonic tissues is likely the placenta (represented by the letter A in the original text).