1. Vaccines work by:

A. Directly killing pathogens
B. Introducing weakened or inactive versions of pathogens to trigger immune response
C. Stimulating production of specific antibodies immediately
D. None of the above

Correct answer: B

Rationale: The correct answer is B: Introducing weakened or inactive versions of pathogens to trigger an immune response. Vaccines work by exposing the immune system to a harmless version of a pathogen, which allows the body to recognize and develop a defense against the pathogen without causing illness. This process stimulates the immune system to produce memory cells that can quickly recognize and attack the pathogen if encountered in the future. Vaccines do not directly kill pathogens (option A) or immediately stimulate the production of specific antibodies (option C). Therefore, option B is the most accurate description of how vaccines work.

2. A table shows the blood pressure readings for different age groups. How do you determine the patient with the highest systolic pressure?

A. Find the largest number in the "systolic pressure" column.
B. Compare the means (averages) of each age group.
C. Add all systolic pressure values and divide by the total number of patients.
D. Subtract the lowest systolic pressure from the highest.

Correct answer: A

Rationale: The best way is to compare the average systolic pressure values for each age group to identify the highest.

3. What is the difference between a prokaryotic cell and a eukaryotic cell?

A. Prokaryotic cells have a nucleus, while eukaryotic cells do not
B. Eukaryotic cells have a nucleus, while prokaryotic cells do not.
C. Prokaryotic cells have membrane-bound organelles, while eukaryotic cells do not.
D. Eukaryotic cells have membrane-bound organelles, while prokaryotic cells do not.

Correct answer: B

Rationale: Rationale: - Prokaryotic cells are simpler and do not have a true nucleus. Their genetic material is located in the nucleoid region, which is not enclosed by a membrane. - Eukaryotic cells are more complex and have a true nucleus that houses the genetic material, enclosed within a nuclear membrane. - Both prokaryotic and eukaryotic cells have organelles, but eukaryotic cells have membrane-bound organelles such as mitochondria, endoplasmic reticulum, and Golgi apparatus, while prokaryotic cells lack these membrane-bound organelles.

4. Which of these organisms belongs to the kingdom Protista?

A. Coral
B. Yeast
C. Euglena
D. Mushroom

Correct answer: C

Rationale: Rationale: A) Coral belongs to the kingdom Animalia, specifically in the phylum Cnidaria. B) Yeast belongs to the kingdom Fungi. C) Euglena is a unicellular organism that belongs to the kingdom Protista. It is a type of protist that has characteristics of both plants and animals. D) Mushroom belongs to the kingdom Fungi. Therefore, among the options provided, only Euglena belongs to the kingdom Protista.

5. What is the process of converting ammonia, a byproduct of protein digestion, into a less toxic form?

A. Deamination
B. Transamination
C. Decarboxylation
D. Hydrolysis

Correct answer: A

Rationale: Rationale: Deamination is the process of removing an amino group from a molecule, such as converting ammonia (NH3) into a less toxic form like urea. Ammonia is a byproduct of protein digestion and needs to be converted into a less toxic form to be excreted from the body. Deamination is a key step in this process, which occurs mainly in the liver through the urea cycle. Transamination involves the transfer of an amino group from one molecule to another, not the removal of an amino group as in deamination. Decarboxylation is the removal of a carboxyl group from a molecule, and hydrolysis is the breakdown of a compound by adding water.

6. Glands that release hormones directly into the bloodstream without ducts are called:

A. Exocrine glands
B. Endocrine glands
C. Apocrine glands
D. Merocrine glands

Correct answer: B

Rationale: The correct answer is B: Endocrine glands. Endocrine glands are specialized glands that release hormones directly into the bloodstream, which then travel to target organs or tissues to regulate various physiological processes. Unlike exocrine glands (choice A), which secrete their products through ducts to specific locations, endocrine glands secrete hormones into the blood for more widespread and systemic effects. Apocrine glands (choice C) release a portion of their cell contents along with the secretions, while merocrine glands (choice D) release their products through exocytosis without any loss of cell material. Therefore, in this case, endocrine glands best describe the glands that release hormones directly into the bloodstream without ducts.