in a covalent bond the shared electrons

ATI TEAS 7

ati teas 7 science

1. In a covalent bond, the shared electrons:

A. Are completely transferred to one atom.
B. Spend more time closer to the more electronegative atom.
C. Remain equidistant between the two atoms.
D. Do not influence the bond strength.

Correct answer: B

Rationale: In a covalent bond, the shared electrons spend more time closer to the more electronegative atom. Electronegativity is the ability of an atom to attract electrons in a chemical bond. The more electronegative atom exerts a stronger pull on the shared electrons, causing them to be closer to that atom. Choice A is incorrect because in a covalent bond, electrons are shared, not completely transferred. Choice C is incorrect as the shared electrons are not equidistant but are closer to one atom due to electronegativity differences. Choice D is incorrect because shared electrons play a significant role in determining the bond strength by the strength of the bond formed through electron sharing.

2. During swallowing, what is the role of the epiglottis, a small flap of cartilage located near the base of the tongue?

A. Initiates the swallowing reflex
B. Grinds food into smaller pieces
C. Covers the trachea to prevent food aspiration
D. Stores saliva for lubrication

Correct answer: C

Rationale: The epiglottis plays a crucial role during swallowing by covering the trachea to prevent food or liquid from entering the airway, which could lead to aspiration. By acting as a lid over the trachea, it ensures that food passes down the esophagus to the stomach, preventing it from entering the lungs. Choice A is incorrect as the swallowing reflex is a coordinated muscular action involving the tongue and throat muscles. Choice B is incorrect as grinding food into smaller pieces is primarily the function of the teeth and the initial stages of digestion. Choice D is incorrect as the storage of saliva for lubrication is not a function of the epiglottis, but rather involves salivary glands.

3. Identify the correct sequence of the 3 primary body planes as numbered 1, 2, and 3 in the above image.

A. Plane 1 is coronal, plane 2 is sagittal, and plane 3 is transverse.
B. Plane 1 is sagittal, plane 2 is coronal, and plane 3 is medial.
C. Plane 1 is coronal, plane 2 is sagittal, and plane 3 is medial.
D. Plane 1 is sagittal, plane 2 is coronal, and plane 3 is transverse.

Correct answer: A

Rationale: In the standard anatomical position, plane 1 (coronal/frontal plane) divides the body into anterior and posterior portions, plane 2 (sagittal plane) divides the body into left and right portions, and plane 3 (transverse/horizontal plane) divides the body into superior and inferior portions. Therefore, the correct sequence is Plane 1 as coronal, Plane 2 as sagittal, and Plane 3 as transverse, which corresponds to Choice A. Choice B is incorrect as it misidentifies the planes. Plane 2 cannot be coronal as it specifically divides the body into left and right portions. Choice C is incorrect as it misidentifies Plane 2 as sagittal when it should be coronal. Choice D is incorrect as it incorrectly designates Plane 2 as coronal when it should be sagittal, leading to an inaccurate sequence of the primary body planes.

4. What presents the correct order of cellular respiration?

A. Glycolysis, Acetyl-CoA, Citric Acid Cycle, Electron Transport Chain
B. Citric Acid Cycle, Glycolysis, Acetyl-CoA, Electron Transport Chain
C. Glycolysis, Acetyl-CoA, Electron Transport Chain, Citric Acid Cycle
D. Glycolysis, Citric Acid Cycle, Electron Transport Chain, Acetyl-CoA

Correct answer: A

Rationale: The correct order of cellular respiration is Glycolysis, Acetyl-CoA, Citric Acid Cycle, and Electron Transport Chain. Glycolysis initiates the breakdown of glucose in the cytoplasm, leading to the formation of pyruvate. This pyruvate is then converted to Acetyl-CoA in the mitochondria, which enters the Citric Acid Cycle to generate energy-rich molecules like NADH and FADH2. Finally, the Electron Transport Chain, located in the inner mitochondrial membrane, utilizes these energy carriers to produce ATP through oxidative phosphorylation. Choice B is incorrect because it starts with the Citric Acid Cycle, which comes after Glycolysis. Choice C is incorrect as it places the Citric Acid Cycle before the Electron Transport Chain. Choice D is incorrect by placing Acetyl-CoA last instead of before the Citric Acid Cycle.

5. What property of a wave determines its pitch in sound waves?

A. Amplitude
B. Frequency
C. Wavelength
D. Speed

Correct answer: B

Rationale: The pitch of a sound wave is determined by its frequency. Frequency is the number of cycles of a wave that occur in a given time period. Higher frequencies correspond to higher pitches, while lower frequencies correspond to lower pitches. Amplitude refers to the intensity or loudness of a sound wave, wavelength is the distance between two consecutive points in a wave, and speed is the rate at which a wave travels through a medium. Therefore, in sound waves, it is the frequency that primarily determines the pitch, making option B the correct answer.