ATI TEAS 7
TEAS 7 practice test free science
1. Which part of the neuron insulates and speeds up the transmission of nerve impulses along the axon?
- A. Dendrite
- B. Myelin sheath
- C. Synapse
- D. Cell body
Correct answer: B
Rationale: The myelin sheath is a fatty layer that surrounds the axon of a neuron, providing insulation and speeding up the transmission of nerve impulses. This insulation helps prevent the loss of electrical signals as they travel along the axon, allowing for faster and more efficient communication within the nervous system. Dendrites are branching extensions of a neuron that receive signals from other neurons, the synapse is the junction between two neurons where communication occurs, and the cell body contains the nucleus and organelles of the neuron, but none of these structures provide insulation for the transmission of nerve impulses along the axon.
2. What is the process by which genetic information is used to produce proteins?
- A. Replication
- B. Transcription
- C. Translation
- D. Mutation
Correct answer: C
Rationale: A) Replication is the process by which DNA is copied to produce an identical strand of DNA. This process occurs during cell division to ensure that each daughter cell receives a complete set of genetic information. B) Transcription is the process by which genetic information from DNA is copied into a complementary RNA molecule. This RNA molecule, known as messenger RNA (mRNA), serves as a template for protein synthesis during translation. C) Translation is the process by which the genetic information carried by mRNA is decoded to produce a specific sequence of amino acids, which are then assembled into a protein. This process occurs at the ribosomes in the cytoplasm of the cell. D) Mutation refers to a change in the DNA sequence that can result in alterations to the genetic information. Mutations can occur spontaneously or be induced by external factors such as radiation or chemicals. While mutations can impact protein synthesis, they are not the process by which genetic inf
3. What is the process of combining two or more substances to form a heterogeneous mixture called?
- A. Dissolving
- B. Diluting
- C. Mixing
- D. Reacting
Correct answer: C
Rationale: The correct answer is 'Mixing.' When substances are combined, a heterogeneous mixture is formed where the components are physically distinguishable. 'Dissolving' (Choice A) is the process of a solute becoming uniformly dispersed in a solvent to form a solution, not a heterogeneous mixture. 'Diluting' (Choice B) refers to reducing the concentration of a solute in a solution. 'Reacting' (Choice D) involves a chemical change where substances interact to form new products, rather than just physically mixing to form a heterogeneous mixture.
4. Which technology allows scientists to directly edit the human genome?
- A. Polymerase Chain Reaction (PCR)
- B. Gel electrophoresis
- C. DNA sequencing
- D. CRISPR-Cas9
Correct answer: D
Rationale: CRISPR-Cas9 is the correct answer. A) Polymerase Chain Reaction (PCR) is used for amplifying specific DNA segments, not directly editing the human genome. B) Gel electrophoresis is for separating DNA fragments by size, not for genome editing. C) DNA sequencing determines DNA nucleotide order but does not directly edit the genome. D) CRISPR-Cas9 technology enables precise modifications in the DNA of organisms, including humans. It guides the Cas9 enzyme to specific genome locations for targeted edits, revolutionizing genetic research and offering various applications in gene editing and therapy. Unlike the other techniques mentioned, CRISPR-Cas9 is specifically designed to make changes in the genetic code itself, making it a powerful tool for genetic manipulation.
5. The number of protons in an atom determines its:
- A. Mass number
- B. Atomic number
- C. Atomic weight
- D. Valence electron count
Correct answer: B
Rationale: The number of protons in an atom is known as the atomic number. The atomic number uniquely identifies an element and determines its position on the periodic table. It is a fundamental property of an element and directly influences its chemical behavior and interactions. The mass number, on the other hand, is the sum of protons and neutrons in the nucleus of an atom, not just protons. Atomic weight is the average mass of an element's isotopes considering their relative abundance, not solely based on the number of protons. Valence electron count refers to the number of electrons in the outermost energy level of an atom, influencing its ability to form bonds and participate in chemical reactions, but it is not determined by the number of protons in the atom.
Similar Questions
Access More Features
ATI TEAS Premium Plus
$149.99/ 90 days
- Actual ATI TEAS 7 Questions
- 3,000 questions with answers
- 90 days access
ATI TEAS Basic
$99/ 30 days
- 3,000 Questions with answers
- 30 days access