ATI TEAS 7
ATI TEAS 7 Version 1 Science Questions
Extract:
Question 1 of 5
Which of the following molecules are found in substantial quantities in both the cell membrane and DNA?
Correct Answer: C
Rationale: Phosphate groups are crucial components of the DNA backbone, forming the phosphodiester bonds between nucleotides. In DNA, the phosphate group connects the 3' carbon of one nucleotide to the 5' carbon of the next nucleotide. In the cell membrane, phospholipids are the main components, with phosphate groups present in the hydrophilic head of the molecule. This key structural feature allows phospholipids to form the lipid bilayer that comprises the cell membrane. While nitrogenous bases are essential components of DNA, they are not found in substantial quantities in the cell membrane. Steroids are not typically abundant in either the cell membrane or DNA. Lipids, although present in the cell membrane, do not have the same substantial presence in DNA as phosphate groups do.
Extract:
Question 2 of 5
Which of the following are the major parts of the nervous system?
Correct Answer: C
Rationale: The nervous system comprises two major parts: the peripheral nervous system (PNS) and the central nervous system (CNS). The PNS includes nerves outside the brain and spinal cord, while the CNS consists of the brain and spinal cord. Choice C (PNS and CNS) correctly identifies the primary divisions of the nervous system, encompassing both the peripheral and central components. Therefore, the correct answer is C.
Question 3 of 5
Which of the following substances is responsible for donating H+ ions to act as a buffer when blood pH rises?
Correct Answer: D
Rationale: Carbonic acid is a pivotal buffer in blood that plays a key role in maintaining pH balance. When blood pH rises, indicating increased alkalinity, carbonic acid releases hydrogen ions (H+) to counterbalance the excess base, thereby preventing significant changes in pH levels. This mechanism highlights the essential function of carbonic acid in regulating the acid-base equilibrium in the blood.
Question 4 of 5
Which substance protects the body from ultraviolet rays?
Correct Answer: D
Rationale: Melanin is the pigment responsible for skin color and serves as a natural defense against ultraviolet (UV) rays. When the skin is exposed to UV rays, melanin production increases to absorb and dissipate the radiation, acting as a protective mechanism. This helps prevent DNA damage, reducing the risk of skin cancer and other UV-induced skin issues. Therefore, melanin is the substance that effectively shields the body from the harmful effects of UV radiation.
Question 5 of 5
Which of the following substances is excreted by the sweat glands in response to the breakdown of proteins and the formation of ammonia?
Correct Answer: C
Rationale: The correct answer is Urea. 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. Urea plays a vital role in the excretory process by helping eliminate nitrogenous wastes from the body and maintaining proper physiological balance.