ati teas 7 science

Correct Answer: A

Rationale: The correct answer is A: Axon. The axon is responsible for transmitting signals away from the cell body towards other neurons or muscles. It is a long, slender projection of the neuron that carries electrical impulses known as action potentials. The axon is covered by the myelin sheath, which helps to speed up the transmission of signals. Summary: - B: Dendrite receives signals from other neurons and transmits them towards the cell body. - C: Synapse is the gap between neurons where neurotransmitters are released to communicate signals. - D: Myelin sheath insulates and speeds up signal transmission along the axon, but it is not responsible for transmitting signals itself.

Correct Answer: A

Rationale: Diastole is the correct answer because it specifically refers to the relaxation phase of the heart muscle. During diastole, the heart fills with blood before contracting in systole. Systole is the contraction phase, not relaxation. Asystole is the absence of heart contractions, not relaxation. Cardiastole is not a recognized term in relation to the heart's relaxation. Therefore, diastole is the most appropriate term for describing the relaxation of the heart muscle.

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.

Correct Answer: D

Rationale: The correct answer is D because water's unique polarity allows it to dissolve a wide range of substances. Water's polar covalent bonds enable it to form hydrogen bonds with other molecules, facilitating dissolution. Water's ability to dissolve various substances is crucial for biological processes such as nutrient absorption and waste removal. Choice A is incorrect because water is neutral in terms of its pH, not inherently having a neutral pH. Choice B is incorrect because water actually has a high specific heat capacity, which is why it can absorb and release large amounts of heat without significant temperature changes. Choice C is incorrect because while water does have polar covalent bonds, this property alone does not fully characterize water as much as its dissolving capabilities do.

Correct Answer: B

Rationale: The correct answer is B: One layer. Simple epithelium consists of a single layer of cells. This arrangement allows for efficient diffusion and absorption due to the short distance between cells and the underlying tissues. Option A is incorrect because epithelial tissue always has at least one layer. Option C is incorrect as it describes stratified epithelium, which has two or more layers. Option D is incorrect as it refers to stratified squamous epithelium, not simple epithelium.