TEAS 7 practice test free science

Correct Answer: D

Rationale: In a symbiotic relationship, both organisms involved benefit from the interaction. This mutually beneficial relationship can take different forms, such as mutualism where both organisms benefit, commensalism where one organism benefits and the other is unaffected, or parasitism where one organism benefits at the expense of the other. In this case, the term 'symbiotic relationship' specifically refers to a scenario where both organisms derive some form of benefit from their interaction. Choices A, B, and C are incorrect because they do not accurately describe a symbiotic relationship. In symbiosis, both organisms benefit, making option D the correct choice.

Correct Answer: A

Rationale: Parkinson's disease is primarily caused by the loss of dopamine-producing neurons in the brain. Dopamine is a neurotransmitter that plays a crucial role in coordinating movement. The reduction of dopamine levels leads to the characteristic motor symptoms of Parkinson's disease, such as tremors, rigidity, and bradykinesia. Choice B, acetylcholine, is involved in functions like muscle contraction and autonomic nervous system regulation but is not primarily affected in Parkinson's disease. Serotonin (Choice C) is involved in mood regulation and sleep, not the main neurotransmitter affected in Parkinson's disease. Glutamate (Choice D) is the major excitatory neurotransmitter in the central nervous system and is not primarily implicated in Parkinson's disease pathophysiology.

Correct Answer: C

Rationale: Amphiprotic substances are those that can both donate and accept protons. They possess characteristics of both acids and bases, making them capable of acting as proton donors and proton acceptors. Choices A and B represent substances that are specific to either donating or accepting protons. Choice D does not describe a substance's ability to donate or accept protons since neutrality does not inherently involve proton donation or acceptance.

Correct Answer: A

Rationale: The vas deferens is the correct answer. It is the tube that carries sperm from the testes to the urethra during ejaculation. The vas deferens plays a crucial role in transporting mature sperm for ejaculation. The epididymis is responsible for sperm maturation and storage, not the direct passage of sperm to the urethra. The seminal vesicle produces fluid that combines with sperm to form semen but is not the tube for sperm transport. The urethra serves as the passageway for both urine and semen out of the body but is not the specific tube that transports sperm from the testes to the urethra.

Correct Answer: B

Rationale: Endocrine glands release hormones directly into the bloodstream without the use of ducts. This allows the hormones to be distributed throughout the body to target organs or tissues. Exocrine glands, on the contrary, release their secretions through ducts to the external environment or onto a surface, such as sweat glands. Apocrine and merocrine glands are both types of exocrine glands that release their secretions through different mechanisms. Apocrine glands release their secretions along with portions of the cell itself, while merocrine glands release their secretions through exocytosis without loss of cellular material.