Which of the following vessels carries oxygenated blood?
A. Superior vena cava
B. Inferior vena cava.
C. Pulmonary artery
D. Pulmonary vein
The pulmonary veins are the vessels that carry oxygenated blood from the lungs to the left atrium of the heart.
Choice A is not correct because the superior vena cava carries deoxygenated blood from the upper body to the right atrium of the heart.
Choice B is not correct because the inferior vena cava carries deoxygenated blood from the lower body to the right atrium of the heart.
Choice C is not correct because the pulmonary artery carries deoxygenated blood from the right ventricle of the heart to the lungs.
Therefore, the Correct Answer is D.
More Questions on TEAS 7 Science
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Q #1: Which of the following types of cells produce and release antibodies?
A. Natural killer cells
B. Cytotoxic T-cells
C. Plasma B cells
D. Helper T-cells
Answer Explanation
Plasma B cells.
Antibodies are produced by specialized white blood cells called B lymphocytes (or B cells).
When an antigen binds to the B-cell surface, it stimulates the B cell to divide and mature into a group of identical cells called a clone.
The mature B cells, called plasma cells, secrete millions of antibodies into the bloodstream and lymphatic system.
Choice A, Natural killer cells, is not the correct answer because natural killer cells are a type of white blood cell that play a major role in the host-rejection of both tumors and virally infected cells.
Choice B, Cytotoxic T-cells, is not the correct answer because cytotoxic T-cells are a type of white blood cell that kills cancer cells, cells that are infected (particularly with viruses), or cells that are damaged in other ways.
Choice D, Helper T-cells, is not the correct answer because helper T-cells are a type of white blood cell that play an important role in the immune system by helping other white blood cells fight infections.
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Q #2: Which of the following can lead to a tsunami?
A. Sunspot activity
B. Lightning strikes.
C. Earthquakes
D. Flooding.
Answer Explanation
A tsunami is a catastrophic ocean wave that is usually caused by a submarine earthquake.
It can also be caused by an underwater or coastal landslide, the eruption of a volcano, or the impact of a meteor or comet in a body of water.
Choice A is not correct because sunspot activity does not cause tsunamis.
Choice B is not correct because lightning strikes do not cause tsunamis.
Choice D is not correct because flooding does not cause tsunamis.
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Q #3: Which of the following is the number of protons in a lithium atom?
A. 7
B. 3
C. 12
D. 4
Answer Explanation
The atomic number of an element represents the number of protons in the nucleus of an atom of that element.
Since lithium has an atomic number of 3, it has 3 protons in its nucleus.
Choice A is not correct because 7 is the mass number of lithium, not the number of protons.
Choice C is not correct because 12 is not the atomic number or mass number of lithium.
Choice D is not correct because 4 is not the atomic number or mass number of lithium.
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Q #4: The cytoskeleton of a cell is comprised of which of the following macromolecules?
A. Carbohydrates
B. Nucleic acids
C. Lipids
D. Proteins
Answer Explanation
The cytoskeleton of a cell is comprised of protein fibers that provide structural support and help maintain the shape of the cell.
These protein fibers include microfilaments, intermediate filaments, and microtubules.
Choice A.
Carbohydrates is not the correct answer because carbohydrates are a type of macromolecule that provides energy to cells and are not a component of the cytoskeleton.
Choice B.
Nucleic acids is not the correct answer because nucleic acids are macromolecules that store and transmit genetic information and are not a component of the cytoskeleton.
Choice C.
Lipids is not the correct answer because lipids are a type of macromolecule that makes up cell membranes and are not a component of the cytoskeleton.
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Q #5: What is the approximate threshold value for mammalian neurons?
A. -55 mV
B. -80 mV
C. +35 mV
D. 0 mV
Answer Explanation
The approximate threshold value for mammalian neurons is -55 mV.
The threshold potential is the critical level to which a membrane potential must be depolarized to initiate an action potential.
Most often, the threshold potential is a membrane potential value between –50 and –55 mV
The membrane potential of a neuron is determined by the distribution of ions across the cell membrane.
At rest, the inside of a neuron is more negative than the outside due to the presence of negatively charged proteins and other molecules.
The movement of ions across the cell membrane can change the membrane potential.
For example, when sodium ions enter the cell, they make the inside of the cell more positive (less negative), causing depolarization.
Choice B is incorrect because -80 mV is below the typical threshold value for mammalian neurons.
Choice C is incorrect because +35 mV is above the typical threshold value for mammalian neurons.
Choice D is incorrect because 0 mV is above the typical threshold value for mammalian neurons.
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Q #6: Which of the following is the function of a totipotent cell?
A. Fights infectious diseases.
B. Aids in the maturation of sex cells.
C. Carries electrical impulses.
D. Develops into any kind of cell.
Answer Explanation
A totipotent cell can self-renew by dividing and develop into the three primary germ cell layers of the early embryo and into extra-embryonic tissues such as the placenta.
A fertilized egg is a totipotent stem cell and as such can develop into any specialized cell found in the organism.
Choice A is not correct because totipotent cells do not fight infectious diseases.
Choice B is not correct because totipotent cells do not aid in the maturation of sex cells.
Choice C is not correct because totipotent cells do not carry electrical impulses.
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Q #7: The pleura is a connective tissue sheath that covers which of the following organs?
A. Liver
B. Heart.
C. Spleen
D. Lung
Answer Explanation
The pleura is a double-layered serous membrane that covers each lung and lines the thoracic cage
The pleura is a vital part of the respiratory tract.
Its role is to cushion the lung and reduce any friction that may develop between the lung, rib cage, and chest cavity.
Each pleura (there are two) consists of a two-layered membrane that covers each lung.
The layers are separated by a small amount of viscous (thick) lubricant known as pleural fluid.
The pleura is comprised of two distinct layers: the visceral pleura and the parietal pleura.
The visceral pleura is the thin, slippery membrane that covers the surface of the lungs and dips into the areas separating the different lobes of the lungs (called the hilum).
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Q #8: Which of the following indicates the function of sodium bicarbonate secreted by the pancreas?
A. Sodium bicarbonate is a protease that digests carbohydrates.
B. Sodium bicarbonate stimulates the pyloric sphincter.
C. Sodium bicarbonate inhibits peristalsis.
D. Sodium bicarbonate neutralizes the acidity of chyme.
Answer Explanation
Sodium bicarbonate neutralizes the acidity of chyme.
The pancreas secretes large amounts of sodium bicarbonate, which protects the duodenum by neutralizing the acid that comes from the stomach.
This compound helps neutralize stomach acid generated during the digestive process.
Choice A is incorrect because sodium bicarbonate is not a protease that digests carbohydrates.
Proteases are enzymes that break down proteins, while sodium bicarbonate is a chemical compound that helps neutralize stomach acid.
Choice B is incorrect because sodium bicarbonate does not stimulate the pyloric sphincter.
The pyloric sphincter is a ring of smooth muscle that separates the stomach from the duodenum and regulates the passage of partially digested food (chyme) into the small intestine.
Choice C is incorrect because sodium bicarbonate does not inhibit peristalsis.
Peristalsis is a series of wave-like muscle contractions that move food through the digestive tract.
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Q #9: Which of the following is the process in which an ovarian follicle matures and releases a reproductive egg?
A. Menstruation
B. Fertilization
C. Ovulation
D. Oogenesis
Answer Explanation
Ovulation is the process in which an ovarian follicle matures and releases a reproductive egg.
During ovulation, a mature egg is released from the female ovary, enabling it to be fertilized by male sperm cells 1.
Choice A is incorrect because menstruation is the process of shedding the uterine lining, which occurs when an egg is not fertilized.
Choice B is incorrect because fertilization is the process of a sperm cell joining with an egg cell to form a zygote.
Choice D is incorrect because oogenesis is the process of forming female gametes (eggs) in the ovaries.
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Q #10: Which of the following substances is responsible for donating H+ ions to act as a buffer when blood pH rises?
A. Carbon dioxide
B. Carbon monoxide
C. Carbonic acid
D. Oxygen
Answer Explanation
Carbonic acid.
In the human body, maintaining the pH of the blood within a narrow range is critical for proper physiological functioning.
One of the buffering systems that helps to regulate blood pH involves the conversion of carbon dioxide (CO2) and water (H2O) into carbonic acid (H2CO3), which then dissociates into hydrogen ions (H+) and bicarbonate ions (HCO3-).
Carbonic acid (H2CO3) is responsible for donating H+ ions to act as a buffer when blood pH rises.
When blood pH rises (becomes more alkaline), carbonic acid dissociates, and the H+ ions combine with bicarbonate ions to form more carbonic acid.
This helps to remove excess H+ ions from the blood and prevent the pH from rising too much.
Option A, carbon dioxide, is involved in the buffering system through its conversion to carbonic acid.
However, it does not directly donate H+ ions to act as a buffer when blood pH rises.
Option B, carbon monoxide, is a toxic gas that binds to hemoglobin in red blood cells, preventing them from carrying oxygen.
It is not involved in the buffering system and does not donate H+ ions.
Option D, oxygen, is carried by hemoglobin in red blood cells and is essential for respiration.
It is not involved in the buffering system and does not donate H+ ions.
