a neuron consists of three main parts these are

ATI TEAS 7

ATI TEAS Science Test

1. Which of the following represents the three main parts of a neuron?

A. effector, cell body, axon
B. dendrites, axon, cell body
C. dendrites, axon, receptor
D. synapse, axon, cell body

Correct answer: B

Rationale: A neuron consists of three main parts: dendrites, axon, and cell body. Dendrites receive signals from other neurons or sensory receptors. The cell body (soma) contains the nucleus and organelles essential for neuron function. The axon transmits electrical impulses away from the cell body to other neurons, muscles, or glands. Choice A is incorrect because an effector is not a part of a neuron. Choice C is incorrect because a receptor is not a component of a neuron but rather interacts with neurons. Choice D is incorrect because the synapse is a junction between neurons for signal transmission, not a structural part of a neuron.

2. How does the developing fetus primarily eliminate metabolic wastes?

A. The developing fetus does not produce metabolic wastes.
B. Fetal waste is excreted as feces, which pass into the mother's anus.
C. Fetal waste is passed down the umbilical cord to the mother's circulatory system.
D. Fetal waste is passed down the umbilical cord and leaves the mother's body via the vagina.

Correct answer: C

Rationale: Metabolic wastes produced by the developing fetus are eliminated primarily by being passed down the umbilical cord to the mother's circulatory system. Once in the mother's blood, these wastes are then filtered and excreted by the mother's kidneys. Choice A is incorrect because the developing fetus does produce metabolic wastes. Choice B is incorrect as fetal waste does not pass into the mother's anus. Choice D is incorrect as fetal waste does not leave the mother's body via the vagina.

3. What is the process by which ribosomes use transcribed RNA to assemble the required protein?

A. Translation
B. Transcription
C. Replication
D. Duplication

Correct answer: A

Rationale: Translation is the correct process where ribosomes decode mRNA to synthesize proteins, following the sequence of codons in the mRNA. During translation, ribosomes use the transcribed RNA (mRNA) as a template to assemble amino acids into a protein according to the genetic code carried by the mRNA. Choice B, Transcription, is incorrect as it is the process of synthesizing mRNA from a DNA template. Choice C, Replication, is also incorrect as it involves the duplication of DNA to produce an identical copy. Choice D, Duplication, is not a biological term related to protein synthesis, making it an incorrect choice.

4. What is the general formula for an alkyl halide?

A. CₙH₂ₙ
B. CₙH₂ₙ₊₂
C. CₙH₂ₙ₊₁X
D. CₙH₂ₙO

Correct answer: C

Rationale: The correct answer is option C, 'CₙH₂ₙ₊₁X.' This is the general formula for an alkyl halide, where X represents a halogen atom (such as fluorine, chlorine, bromine, or iodine), and the hydrocarbon chain is represented by CₙH₂ₙ₊₁. Option A, 'CₙH₂ₙ,' is incorrect because it does not account for the presence of a halogen atom. Option B, 'CₙH₂ₙ₊₂,' is incorrect as it represents an alkene, not an alkyl halide. Option D, 'CₙH₂ₙO,' is also incorrect as it suggests the presence of oxygen, which is not characteristic of alkyl halides.

5. In the human skeleton, which of the following lists some of the vertebrae in descending order?

A. Atlas, axis, thoracic, lumbar, sacral, coccyx.
B. Axis, sacral, coccyx, atlas, lumbar, thoracic.
C. Thoracic, sacral, lumbar, axis, coccyx, atlas.
D. Coccyx, lumbar, axis, sacral, thoracic, atlas.

Correct answer: A

Rationale: The correct order of some of the vertebrae in the human skeleton in descending order is Atlas, Axis, Thoracic, Lumbar, Sacral, Coccyx. This sequence follows the typical arrangement from the top of the spine down towards the pelvis. Choice B is incorrect as it does not follow the descending order of vertebrae. Choice C is incorrect as it starts with Thoracic which is not the first vertebra in the descending order. Choice D is incorrect as it starts with Coccyx which is the last vertebra in the descending order.