Which of the following organic molecules contains both an amine and carboxyl group?

A: Lipids
B: Cellulose
C: Chitin
D: Proteins
Correct Answer: D
Rationale: Proteins are composed of amino acids, which contain both an amine (NH2) and carboxyl (COOH) functional groups. The amine group is found at one end of the amino acid molecule, while the carboxyl group is located at the other end. When amino acids join together through peptide bonds, the amine of one amino acid reacts with the carboxyl group of another, forming a protein chain.

Which of the following are the major parts of the nervous system?

A: PNS and Somatic Nervous System
B: Autonomic Nervous System and CNS
C: PNS and CNS
D: Autonomic Nervous System and Somatic Nervous System
Correct Answer: C
Rationale: The nervous system is divided into two major parts: the peripheral nervous system (PNS) and the central nervous system (CNS). The PNS consists of nerves outside the brain and spinal cord, while the CNS includes the brain and spinal cord. Therefore, the correct answer is C.

Which of the following substances is responsible for donating H+ ions to act as a buffer when blood pH rises?

A: Carbon Monoxide
B: Oxygen
C: Carbon Dioxide
D: Carbonic Acid
Correct Answer: D
Rationale: Carbonic acid is a crucial buffer in the blood that helps maintain pH balance. When blood pH rises (becomes more alkaline), carbonic acid donates hydrogen ions (H+) to neutralize the excess base, helping to prevent drastic changes in pH levels. Therefore, carbonic acid plays a key role in regulating the acid-base balance in the blood.

Which of the following substances protects the body from ultraviolet rays?

A: Keratin
B: Sebum
C: Perspiration
D: Melanin
Correct Answer: D
Rationale: Melanin is the pigment responsible for skin color. When skin is exposed to ultraviolet rays, melanin production increases as a defense mechanism to protect the body by absorbing and dissipating the harmful UV radiation. This process helps prevent DNA damage that can lead to skin cancer and other skin-related issues.

Which of the following substances is excreted by the sweat glands in response to the breakdown of proteins and the formation of ammonia?

A: Lysozymes
B: Water
C: Urea
D: Sebum
Correct Answer: C
Rationale: Urea is the correct answer. Sweat glands excrete urea in response to the breakdown of proteins and the formation of ammonia. Urea is a waste product formed in the liver by the breakdown of amino acids. It is then excreted by the kidneys in urine and by sweat glands through perspiration.

Actual ATI TEAS 7 Test Questions Set 1