how do dna and rna function together as part of the human genome

ATI TEAS 7

ATI TEAS 7 Science Practice Test

1. How do DNA and RNA function together as part of the human genome?

A. DNA carries genetic information from RNA to the cell cytoplasm.
B. RNA carries genetic information from DNA to the cell cytoplasm.
C. DNA and RNA carry genetic information from the cell nucleus to the cytoplasm.
D. DNA and RNA do not interact within the cell.

Correct answer: B

Rationale: The correct answer is B. RNA acts as a messenger carrying genetic instructions from the DNA in the nucleus to the cytoplasm, where proteins are synthesized. This process is known as transcription and translation, where DNA provides the blueprint for protein synthesis, and RNA delivers this information to the cellular machinery in the cytoplasm. Choice A is incorrect as it inaccurately states that DNA carries genetic information from RNA, which is the opposite of the actual flow of information. Choice C is incorrect as it suggests that both DNA and RNA together carry genetic information from the nucleus to the cytoplasm, which is not accurate. Choice D is incorrect as DNA and RNA do interact within the cell, playing crucial roles in genetic information processing and protein synthesis.

2. What is the name of the muscular ring that controls the passage of food from the esophagus to the stomach?

A. Pyloric sphincter
B. Cardiac sphincter
C. Ileocecal valve
D. Sphincter of Oddi

Correct answer: B

Rationale: The correct answer is the Cardiac sphincter (lower esophageal sphincter). It is situated at the junction of the esophagus and the stomach, controlling the passage of food into the stomach. The cardiac sphincter opens and closes to regulate the flow of food and prevent reflux. The pyloric sphincter, on the other hand, is located between the stomach and the small intestine, not the esophagus and stomach. The ileocecal valve is positioned between the small and large intestines, while the Sphincter of Oddi is found in the duodenum, not between the esophagus and stomach.

3. What is the basic structural and functional unit of the nervous system?

A. Axon
B. Neuron
C. Dendrite
D. Synapse

Correct answer: B

Rationale: The correct answer is B: Neuron. Neurons are indeed the basic structural and functional units of the nervous system. Neurons are specialized cells that transmit signals throughout the nervous system, enabling communication and coordination of various functions within the body. While axons, dendrites, and synapses are all essential components of neurons and neural function, the neuron as a whole is considered the fundamental building block responsible for signal transmission. Choice A, Axon, is incorrect because an axon is a part of a neuron responsible for transmitting electrical signals away from the cell body. Choice C, Dendrite, is incorrect because dendrites are extensions of a neuron that receive signals from other neurons. Choice D, Synapse, is incorrect because a synapse is the junction between two neurons where signals are transmitted.

4. In the electron cloud model, electrons occupy specific energy levels around the nucleus with varying probabilities. This model depicts electrons existing in distinct energy levels, not fixed orbits, with probabilities of finding them in specific regions.

A. 2 protons and 6 neutrons
B. 2 filled s orbitals and 6 filled p orbitals
C. 2s orbitals with 2 and 6 electrons, respectively
D. 4 filled electron shells

Correct answer: C

Rationale: The electron cloud model describes electrons existing in distinct energy levels, not fixed orbits. Option C correctly describes the electron configuration of an atom with 2s orbitals containing 2 electrons and 6 electrons in the 2p orbitals. This configuration aligns with the electron cloud model where electrons are found in specific energy levels with varying probabilities. Options A, B, and D do not accurately represent the electron cloud model.

5. What is the process of breaking down glucose into pyruvate called?

A. Glycolysis
B. Gluconeogenesis
C. Krebs cycle
D. Oxidative phosphorylation

Correct answer: A

Rationale: A) Glycolysis is the process of breaking down glucose into pyruvate. This occurs in the cytoplasm of cells and is the first step in cellular respiration. B) Gluconeogenesis is the process of synthesizing glucose from non-carbohydrate sources, such as amino acids or glycerol, and is the opposite of glycolysis. C) The Krebs cycle, also known as the citric acid cycle, is a series of chemical reactions that occur in the mitochondria and is involved in the oxidation of acetyl-CoA to produce ATP and other energy carriers. D) Oxidative phosphorylation is the final stage of cellular respiration where ATP is produced through the transfer of electrons in the electron transport chain.