TEAS 7 Biology: Master Key Concepts

ATI TEAS 7

Biology

1. What is the process of copying DNA called?

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

Correct answer: C

Rationale: Rationale: A) Transcription is the process of creating an RNA copy of a segment of DNA. It involves the synthesis of mRNA from a DNA template. B) Translation is the process of synthesizing a protein from an mRNA template. It involves the conversion of the mRNA sequence into a sequence of amino acids. C) Replication is the process of copying DNA to produce an identical copy. During replication, the DNA double helix unwinds and each strand serves as a template for the synthesis of a new complementary strand, resulting in two identical DNA molecules. D) Mutation refers to a change in the DNA sequence that can result from errors during replication, exposure to mutagens, or other factors. While mutations can occur during replication, the process of copying DNA itself is called replication.

2. Decomposers in an ecosystem play a vital role by:

A. Photosynthesizing and producing organic matter
B. Breaking down dead organisms and returning nutrients to the environment
C. Preying on herbivores and controlling their populations
D. Fixing nitrogen from the atmosphere and making it available to plants

Correct answer: B

Rationale: Rationale: Decomposers are organisms that break down dead organic matter, such as dead plants and animals, into simpler substances. By doing so, they help to recycle nutrients back into the environment, making them available for other organisms to use. This process is essential for the functioning of ecosystems, as it ensures that nutrients are not lost but instead are continuously cycled through the ecosystem. Photosynthesis (option A) is the process by which plants and some other organisms convert light energy into chemical energy in the form of glucose, and it is not a role of decomposers. Preying on herbivores (option C) is a role typically carried out by predators, not decomposers. Fixing nitrogen from the atmosphere (option D) is a process carried out by nitrogen-fixing bacteria, not decomposers.

3. Which of the following is a strong base commonly used in cleaning products?

A. Sodium hydroxide (NaOH)
B. Ammonium hydroxide (NHâ‚„OH)
C. Calcium hydroxide (Ca(OH)â‚‚)
D. Potassium hydroxide (KOH)

Correct answer: A

Rationale: Sodium hydroxide is a strong base commonly used in cleaning products. The other choices are also bases but are not as strong as sodium hydroxide.

4. Which of the following structures is responsible for preventing the backflow of blood from the left ventricle into the left atrium?

A. Aortic valve
B. Pulmonary valve
C. Tricuspid valve
D. Mitral valve

Correct answer: D

Rationale: The correct answer is D, the mitral valve. The mitral valve, also known as the bicuspid valve, is located between the left atrium and the left ventricle. Its main function is to prevent the backflow of blood from the left ventricle into the left atrium during ventricular contraction. The aortic valve (A) is responsible for preventing the backflow of blood from the aorta into the left ventricle, the pulmonary valve (B) prevents backflow from the pulmonary artery into the right ventricle, and the tricuspid valve (C) prevents backflow from the right ventricle into the right atrium. Therefore, the mitral valve is specifically responsible for preventing backflow in the left side of the heart, making it the correct answer in this case.

5. The basic unit of communication in the nervous system is called a:

A. Neuron
B. Astrocyte
C. Neurotransmitter
D. Synapse

Correct answer: A

Rationale: The basic unit of communication in the nervous system is a neuron. Neurons are specialized cells that transmit information through electrical and chemical signals. They form complex networks to relay messages throughout the body. Astrocytes are support cells that help maintain the environment around neurons. Neurotransmitters are chemicals that transmit signals between neurons at synapses. A synapse is a junction between two neurons where communication occurs. However, the primary unit responsible for communication in the nervous system is the neuron, making it the correct answer.