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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.

Therefore, the Correct Answer is D.

More Questions on TEAS 7 Science

  • Q #1: Nitrogen gas is an extremely stable molecule because of which of the following?

    A. Ionic bonds

    B. Hydrogen bonds

    C. Resonance bonds

    D. Triple covalent bonds

    Answer Explanation

    Triple covalent bonds.

    Nitrogen gas (N2) is an extremely stable molecule because it consists of two nitrogen atoms bonded together by a triple covalent bond.

    A covalent bond is a type of chemical bond where atoms share electrons to form a molecule.

    In a triple covalent bond, three pairs of electrons are shared between the two atoms, resulting in a very strong bond that makes the molecule extremely stable.

     

    Choice A.

    Ionic bonds is not correct because ionic bonds involve the transfer of electrons from one atom to another to form ions, which are then attracted to each other due to their opposite charges.

    Nitrogen gas does not contain ions and is not held together by ionic bonds.

    Choice B.

    Hydrogen bonds is not correct because hydrogen bonds are weak electrostatic attractions between molecules that contain hydrogen atoms bonded to highly electronegative atoms such as oxygen or nitrogen.

    Nitrogen gas does not contain hydrogen atoms and is not held together by hydrogen bonds.

    Choice C.

    Resonance bonds is not correct because resonance refers to the delocalization of electrons in a molecule where multiple Lewis structures can be drawn to represent the molecule.

    Nitrogen gas has a single Lewis structure and does not exhibit resonance.

  • Q #2: 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.

     

  • Q #3: Which of the following is correct regarding the pH scale?

    A. A substance with a pH of 3 is two times more alkaline than a substance with a pH of 4

    B. A substance with a pH of 3 is two times more acidic than a substance with a pH of 4

    C. A substance with a pH of 3 is 10 times more acidic than a substance with a pH of 4

    D. A substance with a pH of 3 is 10 times more alkaline than a substance with a pH of 4

    Answer Explanation

    The pH scale is a logarithmic scale that measures the acidity or alkalinity of a solution.

    A solution with a pH of 7 is neutral, while a solution with a pH less than 7 is acidic and a solution with a pH greater than 7 is alkaline.

    Because the pH scale is logarithmic, each whole number change in pH represents a tenfold change in acidity or alkalinity.

    Therefore, a substance with a pH of 3 is 10 times more acidic than a substance with a pH of 4.

    Choice A.

    A substance with a pH of 3 is two times more alkaline than a substance with a pH of 4 is not correct because it incorrectly states that the substance with a lower pH is more alkaline and also incorrectly states the magnitude of the difference in acidity or alkalinity.

    Choice B.

    A substance with a pH of 3 is two times more acidic than a substance with a pH of 4 is not correct because it correctly states that the substance with a lower pH is more acidic but incorrectly states the magnitude of the difference in acidity.

    Choice D.

    A substance with a pH of 3 is 10 times more alkaline than a substance with a pH of 4 is not correct because it incorrectly states that the substance with a lower pH is more alkaline.

  • Q #4: Which of the following is used to determine a person's DNA sequence? 

    A. Enzymes

    B. Blood types

    C. Hormones

    D. Genes

    Answer Explanation

    Genes are used in the process of DNA sequencing to determine the order of nucleotides in a DNA molecule.

     

    Choice B.

    Blood types is not the correct answer because blood types are determined by the presence or absence of specific antigens on the surface of red blood cells and are not directly related to DNA sequencing.

    Choice C.

    Hormones is not the correct answer because hormones are chemical messengers produced by glands in the body and are not directly involved in DNA sequencing.

    Choice D.

    Genes is the correct answer because genes are used in the process of DNA sequencing to determine the order of nucleotides in a DNA molecule.

  • Q #5: Which of the following physiological responses is caused by the release of antidiuretic hormone?

    A. Increase in the concentration of calcium in the glomerulus.

    B. Increase in water reabsorption in the collecting duct

    C. Decrease in the concentration of calcium in the glomerulus.

    D. Decrease in water reabsorption in the collecting duct

    Answer Explanation

    Antidiuretic hormone (ADH), also known as vasopressin, is a hormone that helps regulate the amount of water in your body.

    It works to control the amount of water your kidneys reabsorb as they filter out waste from your blood.

     

    Choice A is not correct because an increase in the concentration of calcium in the glomerulus is not a physiological response caused by the release of antidiuretic hormone.

    Choice C is not correct because a decrease in the concentration of calcium in the glomerulus is not a physiological response caused by the release of antidiuretic hormone.

    Choice D is not correct because a decrease in water reabsorption in the collecting duct is not a physiological response caused by the release of antidiuretic hormone.

     

  • Q #6: 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.

     

  • Q #7: Stimulus: 1of 1. A group of students performed an experiment to test terminal velocity, which is the greatest speed obtained by a falling object. The students dropped different numbers of coffee filters and measured the resulting terminal velocity. Which of the following conclusions is supported by the data in the following data table? #OF FILTERS MASS (g) TERMINAL VELOCITY (m/s) 1 1.01 1.74 2 1.99 2.48 3 3.02 3.04 4 4.0 3.50 5 5.01 3.80  

    A. Terminal velocity is when the force of gravity is equal to air resistance.

    B. Heavier objects take more time to reach terminal velocity.

    C. Heavier objects fall faster than lighter objects.

    D. The greater the number of filters, the smaller the terminal velocity.

    Answer Explanation

    Heavier objects fall faster than lighter objects.

    The data in the table shows that as the number of filters (and therefore the mass) increases, the terminal velocity also increases.

    This means that the heavier objects (with more filters) are falling faster than the lighter objects (with fewer filters).

    Choice A is not supported by the data in the table as much as it is true.

    Terminal velocity is indeed when the force of gravity is equal to air resistance, but this definition does not provide any information about the relationship between mass and terminal velocity.

    Choice B is also not supported by the data in the table.

    The data does not provide any information about the time it takes for an object to reach terminal velocity.

    Choice D is not supported by the data in the table.

    The data shows that as the number of filters increases, the terminal velocity also increases.

    This means that the greater the number of filters, the greater (not smaller) the terminal velocity.  

  • Q #8: Which of the following structures in the female reproductive system secretes hormones to maintain the uterine lining during pregnancy?

    A. Umbilical cord

    B. Corpus luteum

    C. Oviduct

    D. Oocyte

    Answer Explanation

    The corpus luteum is a structure that develops in the ovary after an egg has been released.

    It secretes the hormone progesterone, which prepares the uterus for a fertilized egg to implant and helps maintain the uterine lining during pregnancy1.

     

     

    Choice A.

    Umbilical cord is not correct because it is a structure that connects the developing fetus to the placenta and provides nutrients and oxygen to the fetus, but does not secrete hormones.

    Choice C.

    Oviduct is not correct because it is a tube that transports eggs from the ovary to the uterus, but does not secrete hormones.

    Choice D.

    Oocyte is not correct because it is an immature egg cell, but does not secrete hormones.

     

  • Q #9: In a plant in which fuzzy leaves (F) are dominant over smooth leaves (f), which of the following crosses will produce only offspring with smooth leaves?   

    A. FF x FF

    B. Ff x Ff

    C. ff x ff

    D. Ff x ff

    Answer Explanation

    ff.

    In this cross, both parents are homozygous recessive for the smooth leaf trait

    (ff).

    This means that all of their offspring will inherit two copies of the recessive allele (f) and will therefore have smooth leaves.

    Choice A.

    FF x FF is not correct because both parents are homozygous dominant for the fuzzy leaf trait (FF) and all of their offspring will inherit two copies of the dominant allele (F) and will therefore have fuzzy leaves.

    Choice B.

    Ff x Ff is not correct because both parents are heterozygous for the leaf trait (Ff) and their offspring can inherit either one dominant allele (F) or one recessive allele (f) from each parent, resulting in a 3:1 ratio of fuzzy to smooth leaves. Choice D.

    Ff x ff is not correct because one parent is heterozygous for the leaf trait (Ff) while the other is homozygous recessive (ff), resulting in a 1:1 ratio of fuzzy to smooth leaves in their offspring.

     

  • Q #10: 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.