Proteins
An antibiotic binds to tRNA molecules and prevents them from binding to an amino acid. What will happen as a result of this?
a.Protein synthesis will be stopped.
b.Proteins being synthesized will not be folded properly.
c.Protein synthesis will not be able to make the correct mRNA.
d.Proteins being synthesized will be longer than normal.
a.Protein synthesis will be stopped.
A condition known as acidosis will result if the pH of human blood drops below 7.4. How does the human body maintain the blood pH level, thus protecting from large changes in pH?
a.It produces specialized white blood cells that neutralize the blood's pH.
b. It produces buffers that maintain equilibrium of the blood's pH level.
c. The excess acid in the blood diffuses out of the red blood cells to maintain homeostasis.
d. The excess acid is neutralized by water that enters the red blood cells by osmosis to maintain homeostasis.
b. It produces buffers that maintain equilibrium of the blood's pH level.
What type of molecule diffuses across a selectively permeable membrane during the process of osmosis?
a. carbon dioxide
b. glucose
c. oxygen
d. water
d. water
During the light reactions of photosynthesis, energy becomes stored in the compounds ATP and NADPH. A second set of reactions uses this stored energy to produce vital compounds such as glucose. This second set of reactions involves a biochemical pathway known as
a. the Calvin cycle.
b. carbon fixation.
c. photorespiration.
d. photosystem I.
a. the Calvin Cycle
Which substance is produced as a by-product of both glycolysis and aerobic respiration?
a. NADH
b. acetyl CoA
c. ATP
d. glucose
c. ATP
A scientist injected a drug into a mouse that inhibits the formation of mRNA in either the sperm or egg cells.
What could be the result of this alteration?
a.The process of DNA replication will stop.
b.The process of protein synthesis will stop.
c.The process of DNA replication will become uncontrolled.
d.The process of protein synthesis will become uncontrolled.
b. The process of protein synthesis will stop.
What is the advantage of homeostasis?
a. It allows organisms to live in a range of environments.
b. It allows organisms to avoid a variety of predators.
c. It allows organisms to blend into their environment.
d. It allows organisms to reproduce at a faster rate.
a. It allows organisms to live in a range of environments.
A family went on vacation for a week and was unable to water their houseplants. When the family returned their houseplants had wilted, droopy leaves.
What is the best explanation for this observation?
a. The plant cells lost water by osmosis causing the internal turgor pressure to decrease.
b. The plant cells lost water by osmosis causing the internal turgor pressure to increase.
c. The plant cells lost water by diffusion causing the internal turgor pressure to decrease.
d. The plant cells lost water by diffusion causing the internal turgor pressure to increase.
a. The plant cells lost water by osmosis causing the internal turgor pressure to decrease.
When plants undergo photosynthesis, a reaction produces sugar, oxygen, and water. During respiration, stored energy from the products of photosynthesis is converted to usable energy. In what form is the energy stored prior to use in respiration?
a. chemical energy
b. kinetic energy
c. light energy
d. heat energy
a. chemical energy
During an experiment on aerobic cellular respiration, a biologist limits the amount of phosphorus available to a cell culture. How might this affect the cell?
a. The amount of cellular energy would decrease.
b. The amount of cellular energy would increase.
c. The amount of glucose produced would increase.
d. The amount of glucose produced would decrease.
a. The amount of cellular energy would decrease.
A section of DNA codes for the sequence of nitrogenous bases of mRNA to initiate protein synthesis.
What is this process called?
a. replication
b. transcription
c. transduction
d. translation
b. transcription
Which example represents the release of energy for the purpose of maintaining homeostasis?
a. Water enters the cells in the roots of a plant by osmosis.
b. Lactic acid builds up in muscle cells when oxygen is not available.
c. A cell uses ATP to move glucose molecules by active transport.
d. Molecules of air freshener diffuse from a dispenser across a room.
c. A cell uses ATP to move glucose molecules by active transport.
An increase in blood sugar levels causes the release of insulin by the pancreas in an effort to regulate the body’s blood sugar level. Which statement explains how insulin helps in maintaining the sugar levels in the blood?
a. It causes the body’s cells to release water that dilutes the blood sugar.
b. It inhibits the diffusion of sugar into the blood until the sugar level is normalized.
c. It causes the excess sugar in the blood to be excreted out of the body.
d. It triggers the liver to uptake blood sugar and stores it in the form of glycogen.
d. It triggers the liver to uptake blood sugar and stores it in the form of glycogen.
The primary source of energy for nearly all life is the Sun. Which best describes how green plants utilize this energy?
a. Green plants convert radiant energy and compounds into food.
b. Green plants convert thermal energy into organic compounds.
c. Green plants use electromagnetic energy to release heat.
d. Green plants use mechanical energy to release water.
a. Green plants convert radiant energy and compounds into food.
Ava conducted an experiment to determine respiratory rates during different activities. She counted the number of breaths per minute. Ava noted that the number of breaths increases as physical activity increases. Why is there an increase in the number of breaths per minute as activity increases?
a. As activity increases, more oxygen is exhaled.
b. As activity increases, breathing becomes more efficient.
c. As activity increases, the oxygen needs of cells increase.
d. As activity increases, the rate of the heart beating increases.
c. As activity increases, the oxygen needs of cells increase
In an experiment, a segment of DNA and the mRNA transcribed from that DNA segment were extracted. It was observed that the number of nitrogenous bases in the mRNA was less than those contained in the DNA segment.
Which statement best explains the reason for this?
a.mRNA does not contain the nitrogenous base thymine.
b. mRNA has fewer cell functions as compared to DNA.
c.mRNA contains only the nitrogenous bases needed to build one protein or part of a protein
d. mRNA has to be shorter so it can pass through the nuclear membrane.
c. mRNA contains only the nitrogenous bases needed to build one protein or part of a protein
What causes skin to turn red when the human body gets hot?
a. The heat in the body accumulates in the muscles under the skin.
b. The rate of blood flow in the body increases with the heat.
c. The blood vessels near the skin dilate to allow heat loss from the body.
d. The color changes to help accelerate the release of heat from the body.
c. The blood vessels near the skin dilate to allow heat loss from the body.
A student claims that the sugars produced by plants during photosynthesis provide a carbon skeleton that interacts with other elements to form biomolecules like amino acids, lipids, and nucleic acids. Which statement should the student give in support of the claim?
a. All biomolecules are made up of repeating monosaccharides.
b. All biomolecules have nearly the same molecular structures and shapes.
c. All biomolecules break down to release energy in the form of ATP.
d. All biomolecules contain carbon, hydrogen, and oxygen.
d. All biomolecules contain carbon, hydrogen, and oxygen.
How will clear-cutting of forests affect the level of carbon dioxide in the atmosphere?
a. It will decrease because of increased respiration.
b. It will increase because of decreased photosynthesis.
c. It will decrease because of decreased photosynthesis.
d. It will remain constant as respiring animals remove the carbon dioxide.
b. It will increase because of decreased photosynthesis.
Species change their environments. Species also evolve in response to environmental changes. Which is the most likely chronology of biological processes over the course of the development of life on Earth?
a. anaerobic respiration then photosynthesis then aerobic respiration
b. anaerobic respiration then aerobic respiration then photosynthesis
c. photosynthesis then anaerobic respiration then aerobic respiration
d. photosynthesis then aerobic respiration then anaerobic respiration
a. anaerobic respiration then photosynthesis then aerobic respiration
A segment of DNA has been transcribed into RNA. The base sequence of the RNA segment is AACGCUAUU.
From which DNA sequence has the RNA sequence been transcribed?
a. UUGCGTUUU
b. TTGCGTTAT
c. TTGCGATAA
d.UUGCGAUAA
c. TTGCGATAA
Why is sweating an important and effective process for maintaining homeostasis in humans?
a. Sweat forms when water from the cooler air condenses on skin that is warm from physical activity, helping maintain water balance in the body.
b. Sweating is one method that the body uses to get rid of excess, unnecessary water during periods of exercise and activity.
c. Water has a high specific heat, so sweat is able to draw a great deal of heat away from the body to cool people down during periods of exertion.
d. Water mixed with sodium and potassium salts in sweat forms a natural sunscreen to protect people from the damaging effects of UVB rays on the skin.
c. Water has a high specific heat, so sweat is able to draw a great deal of heat away from the body to cool people down during periods of exertion.
How is the function of the mitochondrion important for the role of the ribosome in a eukaryotic cell?
a. The mitochondrion generates the ATP needed by the ribosome to produce carbohydrates.
b. The mitochondrion generates the proteins needed by the ribosome to produce ATP.
c. The mitochondrion generates the carbohydrates that provide the energy needed for the ribosome to produce ATP.
d. The mitochondrion generates the ATP that provides the energy needed for the ribosome to produce proteins.
d. The mitochondrion generates the ATP that provides the energy needed for the ribosome to produce proteins.
Both the reactants and products of photosynthesis contain carbon (C), hydrogen (H), and oxygen (O), but the products contain greater energy than the reactants. How can the products of photosynthesis have greater energy than the reactants?
a. because the particles in the products move faster than in the reactants
b. because the reaction increased the masses of the nuclei in the products
c. because after the products were exposed to sunlight their electrical charges increased
d. because more energy is stored in the chemical bonds of the products than the reactants
d. because more energy is stored in the chemical bonds of the products than the reactants
Cellular respiration results in the production of adenosine triphosphate (ATP) molecules for energy. The most efficient form of cellular respiration would result in the production of ATP along with which substances?
a. oxygen and energy
b. glucose and glycogen
c. lactic acid and alcohol
d. carbon dioxide and water
d. carbon dioxide and water