TEAS 7 practice test free science

Correct Answer: A

Rationale: The most widely accepted scientific theory for the origin of life on Earth is abiogenesis, which suggests that life arose from simple organic molecules in a primordial soup. This theory is supported by experiments such as the Miller-Urey experiment, which demonstrated that the basic building blocks of life could have formed under early Earth conditions. While there are other hypotheses and ongoing research in this field, the primordial soup theory is currently the most plausible explanation for the origin of life on Earth. Option B, spontaneous generation from non-living matter, has been disproven and is not considered a valid explanation. Option C, the arrival of extraterrestrial life forms, lacks evidence and is not a widely accepted theory. Option D, stating that we still don't know for sure, is true to some extent as the origin of life is a complex topic, but current scientific understanding leans towards abiogenesis from simple organic molecules in a primordial soup.

Correct Answer: C

Rationale: A commensal relationship is a type of symbiotic relationship in which one organism benefits, while the other is neither harmed nor benefited. In this case, E. coli living in the gut is an example of a commensal relationship because it can benefit from the environment in the gut without causing harm to the human host. Option A, Salmonella causing food poisoning, is an example of a pathogenic relationship where the microorganism causes harm to the host. Option B, Staphylococcus aureus causing skin infections, is also an example of a pathogenic relationship where the microorganism causes harm to the host. Option D, Rabies virus causing neurological disease, is another example of a pathogenic relationship where the microorganism causes harm to the host.

Correct Answer: D

Rationale: Theta waves are the correct answer as they are often seen during REM (rapid eye movement) sleep, the stage of sleep closely related to dreaming. Theta waves have a frequency of 4-7 Hz and are typically present during deep relaxation, meditation, and light sleep stages. Delta waves (choice A) are associated with deep sleep stages, not REM sleep. Alpha waves (choice B) are present during wakefulness and relaxation but not predominantly during REM sleep. Beta waves (choice C) are associated with alertness, problem-solving, and active thinking, not specifically with REM sleep or dreaming.

Correct Answer: A

Rationale: In the sentence 'He gave his mother a bouquet of flowers,' the indirect object is 'his mother' because she is the recipient of the action of giving. The direct object is 'a bouquet of flowers' because it is the thing being given. The verb 'gave' is the action being performed. Choice B, 'bouquet,' is incorrect as it is the direct object, not the indirect object. Choice C, 'flowers,' is incorrect as it is part of the direct object phrase. Choice D, 'gave,' is incorrect as it is the verb indicating the action, not an object.

Correct Answer: C

Rationale: Reactions that require light energy to proceed are classified as photochemical reactions. Photochemical reactions involve the absorption of light energy to initiate a chemical reaction. Combustion reactions involve the rapid combination of a substance with oxygen, endothermic reactions absorb heat from the surroundings, and double displacement reactions involve the exchange of ions between two compounds. Therefore, the correct term for reactions requiring light energy is 'photochemical reactions,' making option C the correct answer.