Which type of bond is responsible for the unique properties of water and plays a crucial role in the structure of DNA and proteins?
A. Hydrogen bonds.
B. Covalent bonds.
C. Ionic bonds.
D. Van der Waals forces.
The correct answer is choice A. Hydrogen bonds.
Hydrogen bonds are responsible for the unique properties of water and play a crucial role in the structure of DNA and proteins.
Hydrogen bonds are weak electrostatic attractions between a hydrogen atom covalently bonded to an electronegative atom and another electronegative atom.
Choice B.
Covalent bonds is incorrect because covalent bonds are strong chemical bonds formed by the sharing of electrons between two atoms.
Choice C.
Ionic bonds is incorrect because ionic bonds are chemical bonds formed by the transfer of electrons from one atom to another, resulting in the formation of ions.
Choice D.
Van der Waals forces is incorrect because Van der Waals forces are weak intermolecular forces that arise from temporary dipoles induced in atoms or molecules.
Therefore, the Correct Answer is A.
More Questions on TEAS 7 Science
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Q #1: What is the function of the neuromuscular junction?
A. To connect muscle fibers to motor neurons
B. To bind acetylcholine to nAChRs
C. To depolarize the muscle cell membrane D.
D. To activate voltage-gated sodium channels on the muscle membrane .
Answer Explanation
The neuromuscular junction is a type of synapse where neuronal signals from the brain or spinal cord interact with skeletal muscle fibers, causing them to contract.
The activation of many muscle fibers together causes muscles to contract, which in turn can produce movement.
Choice B is incorrect because binding acetylcholine to nAChRs is a process that occurs at the neuromuscular junction, but it is not the function of the neuromuscular junction itself.
Choice C is incorrect because depolarizing the muscle cell membrane is a result of the function of the neuromuscular junction, but it is not the function itself.
Choice D is incorrect because activating voltage-gated sodium channels on the muscle membrane is a result of the function of the neuromuscular junction, but it is not the function itself.
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Q #2: How do neurons communicate with each other?
A. Through electrical signals only
B. Through chemical signals only
C. Through electrical and chemical signals
D. Through mechanical signals only.
Answer Explanation
Neurons communicate with each other through both electrical and chemical signals.
The electrical signal, or action potential, runs from the cell body area to the axon terminals, through a thin fiber called axon.
Neurons also communicate with one another at junctions called synapses.
At a synapse, one neuron sends a message to a target neuron—another cell.
Most synapses are chemical; these synapses communicate using chemical messengers.
Choice A is incorrect because neurons communicate not only through electrical signals but also through chemical signals.
Choice B is incorrect because neurons communicate not only through chemical signals but also through electrical signals.
Choice D is incorrect because neurons do not communicate through mechanical signals.
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Q #3: Which process involves the fusion of male and female gametes resulting in the formation of a zygote?
A. Oogenesis.
B. Fertilization.
C. Meiosis.
D. Mitosis.
Answer Explanation
Fertilization.
Fertilization is the process by which male and female gametes fuse to form a zygote.
Oogenesis (choice A) is the process by which female gametes, or eggs, are produced.
Meiosis (choice C) is a type of cell division that results in the formation of gametes.
Mitosis (choice D) is a type of cell division that results in the formation of two identical daughter cells.
