What is the largest organ in the human body by surface area?

A. Brain

B. Heart

C. Liver

D. Skin

Answer Explanation:

The largest organ in the human body by surface area is the skin. It covers the entire external surface of the body and has an average surface area of about 20 square feet in adults.

Therefore, the Correct Answer is D.

Q #1: Which of the following describes the function of ligaments?

A. Ligaments attach skeletal muscles to bone

B. Ligaments attach two bones

C. Ligaments attach bones to tendons

D. Ligaments attach skeletal muscles to tendons

Answer Explanation

Ligaments are tough bands of fibrous tissue that connect two bones together in a joint. They provide stability and support to the joint, preventing excessive movement and helping to maintain proper alignment of the bones.
Q #2: What is the difference between a monosaccharide and a disaccharide?

A. Monosaccharides are composed of two sugar molecules while disaccharides are composed of a single sugar molecule.

B. Monosaccharides are simple sugars that cannot be further broken down into simpler sugars while disaccharides are composed of two simple sugars.

C. Monosaccharides are only found in plants while disaccharides are only found in animals.

D. Monosaccharides are used for energy storage while disaccharides are used for structural purposes.

Answer Explanation

Carbohydrates are one of the main types of biomolecules and are composed of monomers called monosaccharides. Monosaccharides are simple sugars that cannot be further broken down into simpler sugars. They are usually composed of 3 to 7 carbon atoms and have a general formula of (CH2O)n, where n is a number between 3 and 7. Examples of monosaccharides include glucose, fructose, and galactose.

When two monosaccharides are joined together by a glycosidic bond, they form a disaccharide. Disaccharides are composed of two simple sugars and can be broken down into their constituent monosaccharides by hydrolysis. Examples of disaccharides include sucrose, lactose, and maltose.

Option a) is incorrect because it describes the composition of a disaccharide, not a monosaccharide. Option

c) is incorrect because both monosaccharides and disaccharides can be found in both plants and animals.

Option d) is incorrect because both monosaccharides and disaccharides can be used for energy storage and

structural purposes, depending on their specific structure and function in the organism.
Q #3: What is the difference between innate and adaptive immunity?

A. Innate immunity is present at birth while adaptive immunity is acquired after exposure to pathogens.

B. Innate immunity is specific to particular pathogens while adaptive immunity is nonspecific.

C. Innate immunity is mediated by antibodies while adaptive immunity is mediated by T cells.

D. Innate immunity provides long-term protection while adaptive immunity provides only short-term protection.

Answer Explanation

Innate immunity and adaptive immunity are two arms of the immune system that work together to protect the body from pathogens. Innate immunity is the first line of defense and is present at birth. It includes physical and chemical barriers such as the skin, mucous membranes, and antimicrobial peptides, as well as cells such as macrophages and natural killer cells that can quickly recognize and atack pathogens. Innate immunity is nonspecific, meaning it responds to a wide variety of pathogens in a similar way.

Adaptive immunity, on the other hand, is acquired after exposure to pathogens. It involves the production of antibodies and activation of T cells, which are specific to particular pathogens. Adaptive immunity takes longer to develop than innate immunity, but it provides a more specific and targeted response to pathogens. Once the adaptive immune system has been activated against a particular pathogen, it can provide long-term protection against future infections with that pathogen.

Option b) is incorrect because innate immunity is nonspecific while adaptive immunity is specific. Option c) is incorrect because antibodies are a part of adaptive immunity while T cells can be a part of both innate and adaptive immunity. Option d) is incorrect because adaptive immunity can provide long-term protection, while innate immunity provides immediate but short-lived protection.
Q #4: What is the chemical formula for water?

A. H2O

B. CO2

C. NaCl

D. C6H12O6

Answer Explanation

The chemical formula for water is H2O. It consists of two hydrogen atoms and one oxygen atom.
Q #5: What is the name of the valve that separates the left atrium and left ventricle in the heart?

A. Aortic valve

B. Mitral valve

C. Tricuspid valve

D. Pulmonary valve

Answer Explanation

The mitral valve is located between the left atrium and left ventricle of the heart and helps to regulate the ﬂow of blood between these chambers. It consists of two leaﬂets or ﬂaps that open and close in response to changes in pressure as the heart beats.

During diastole, when the heart is relaxed and filling with blood, the mitral valve opens to allow blood to ﬂow from the left atrium into the left ventricle. During systole, when the heart contracts to pump blood out of the left ventricle and into the systemic circulation, the mitral valve closes to prevent backﬂow of blood into the left atrium.

The mitral valve is one of four valves in the heart that help to ensure the unidirectional ﬂow of blood through the heart and the rest of the circulatory system. Problems with the mitral valve, such as mitral valve prolapse or mitral stenosis, can lead to a range of symptoms and complications, including shortness of breath, fatigue, chest pain, and heart failure.
Q #6: What is the primary pigment responsible for photosynthesis in plants?

A. Chlorophyll a

B. Chlorophyll b

C. Carotenoids

D. Anthocyanins

Answer Explanation

Chlorophyll a is the primary pigment responsible for photosynthesis in plants. It is a green pigment that is essential for capturing light energy from the sun and converting it into chemical energy that can be used by the plant. Chlorophyll a absorbs light most efficiently in the blue and red parts of the spectrum, and reﬂects green light, giving plants their characteristic green color

Chlorophyll b is another type of chlorophyll that is also involved in photosynthesis, but it is not as abundant as chlorophyll a. Chlorophyll b absorbs light most efficiently in the blue and orange parts of the spectrum and reﬂects yellow-green light.

Carotenoids are pigments that are present in many plants and are involved in photosynthesis as well as protecting the plant from damage caused by excess light. Carotenoids are responsible for the orange, yellow, and red colors of many fruits and vegetables.

Anthocyanins are pigments that give plants their red, purple, and blue colors. While they are not directly involved in photosynthesis, they play a role in atracting pollinators and protecting the plant from damage caused by UV radiation.
Q #7: What are the three types of salivary glands and where are they located in the mouth?

A. Parotid, sublingual, and submandibular glands located in the cheeks, tongue, and roof of the mouth, respectively.

B. Sublingual, submandibular, and buccal glands located in the tongue, cheeks, and lips, respectively.

C. Parotid, sublingual, and submandibular glands located in the roof of the mouth, cheeks, and under the jawbone, respectively.

D. Sublingual, parotid, and buccal glands located in the tongue, cheeks, and lips, respectively.
Answer Explanation

The three major pairs of salivary glands are the parotid glands, sublingual glands, and submandibular glands.
- Parotid glands are located just in front of your ears.
- Sublingual glands are located below either side of your tongue, under the floor of your mouth.
- Submandibular glands are located below your jaw.
Q #8: What is the role of the epididymis in sperm maturation?

A. The epididymis produces sperm cells.

B. The epididymis stores and protects sperm cells until ejaculation.

C. The epididymis is responsible for the transport of sperm cells from the testes to the urethra.

D. The epididymis provides nourishment to sperm cells.

Answer Explanation

The epididymis is a coiled tube located at the back of each testicle where the sperm mature and are stored until ejaculation. Sperm are produced in the testes and then transported to the epididymis where they undergo maturation and become motile. The epididymis provides a protective environment for the sperm, allowing them to mature and become more resilient to external stressors. During ejaculation, the sperm are transported from the epididymis to the vas deferens and then to the urethra for ejaculation.
Q #9: Which of the following describes the process of osmosis?

A. Movement of substances from an area of high concentration to an area of low concentration.

B. Movement of substances against a concentration gradient with the help of transport proteins.

C. Movement of water molecules from an area of high concentration to an area of low concentration through a selectively permeable membrane.

D. Movement of substances into a cell by engulfing them with the plasma membrane.

Answer Explanation

Osmosis is the process by which water molecules move across a selectively permeable membrane from an area of high concentration to an area of low concentration, in order to equalize the concentration of solutes on both sides of the membrane. Selectively permeable membranes allow only certain molecules to pass through, while preventing the passage of others.

In osmosis, the movement of water molecules is driven by the concentration gradient of solutes, which cannot pass through the membrane. If one side of the membrane has a higher concentration of solutes than the other, water molecules will move from the side with the lower concentration of solutes to the side with the higher concentration of solutes, in an atempt to dilute the solutes and equalize the concentration on both sides.

Osmosis is important in many biological processes, including the uptake of water by plant roots, the regulation of water balance in animal cells, and the preservation of food by adding salt or sugar to create a hypertonic environment that inhibits bacterial growth.
Q #10: Which of the following is responsible for carrying amino acids to ribosomes during protein synthesis?

A. tRNA

B. mRNA

C. rRNA

D. DNA

Answer Explanation

Transfer RNA (tRNA) is responsible for carrying amino acids to ribosomes during protein synthesis. Each tRNA molecule has a specific anticodon that matches a codon on the messenger RNA (mRNA) molecule. The tRNA molecule binds to the mRNA codon and brings the corresponding amino acid to the ribosome, where it is added to the growing polypeptide chain.