ati teas 7 science

Correct Answer: A

Rationale: The P wave on an ECG represents atrial depolarization. During the cardiac cycle, the electrical impulse originates in the sinoatrial (SA) node, causing the atria to contract. This depolarization of the atria is reflected as the P wave on the ECG. This occurs before the ventricles depolarize (choice B), repolarize (choice D), or before the atria repolarize (choice C). Therefore, the correct answer is A because the P wave specifically represents atrial depolarization in the cardiac cycle.

Correct Answer: A

Rationale: The correct answer is A: Hypothesis. In the scientific method, a scientist creates a hypothesis based on observations or research. A model can be a representation or simulation of a process or system that helps in understanding or predicting outcomes. By creating a model during the hypothesis step, the scientist can visually or conceptually test their proposed explanation or prediction. This aids in designing experiments or gathering data to test the hypothesis further. Data analysis (B) occurs after experimentation, where collected data is analyzed. Experimentation (C) involves testing the hypothesis through controlled experiments. Conclusion (D) is the final step where the scientist interprets the results.

Correct Answer: C

Rationale: The correct answer is C: Total lung capacity. Total lung capacity is the maximum volume of air the lungs can hold after a full forced inhalation. It includes all the volumes within the lungs, such as tidal volume, inspiratory reserve volume, expiratory reserve volume, and residual volume. It is the sum of vital capacity and residual volume. Inspiratory capacity (A) is the maximum volume of air that can be inhaled after a normal exhalation. Tidal volume (B) is the volume of air inspired or expired during normal breathing. Vital capacity (D) is the maximum volume of air that can be exhaled after a maximum inhalation, not the total volume the lungs can hold.

Correct Answer: D

Rationale: The correct answer is D: Pancreas. The pancreas produces insulin and glucagon, which are hormones involved in regulating blood sugar levels. Insulin helps lower blood sugar levels, while glucagon helps raise them. The salivary glands (A) produce saliva for digestion, the liver (B) plays a role in metabolism and detoxification, and the gallbladder (C) stores and releases bile to aid in digestion. Therefore, the pancreas is the correct organ responsible for producing insulin and glucagon.

Correct Answer: A

Rationale: The correct answer is A: Musca domestica. The scientific name for the common housefly is Musca domestica. "Musca" refers to the genus name, while "domestica" refers to the species name. This specific binomial nomenclature system is used in taxonomy to classify and identify organisms. The other choices are incorrect because: B: Drosophila melanogaster refers to the fruit fly, C: Apis mellifera is the honeybee, and D: Anopheles gambiae is a mosquito species. Each of these options represents different species within the insect family, but only A corresponds to the common housefly.