DNA
What is the significance of three consecutive nucleotides in DNA?
A) They code for one amino acid.
B) They code for three amino acids.
C) They code for one complete protein.
D) They code for three complete proteins.
A) They code for one amino acid.
An enzyme has an optimal temperature of 25°C. During an experiment, which action would most likely increase the rate of the reaction?
A) decreasing the light intensity
B) increasing the temperature above 25°C
C) decreasing the amount of substrate available
D) increasing the temperature from 15°C to 25°C
D) increasing the temperature from 15°C to 25°C
A patient takes medication to treat strep throat caused by the bacteria Streptococcus pyogenes. Which statement best describes the reproductive success of the bacteria after the patient has taken the medication for a period of time?
A) The bacteria may develop resistance to the medication and continue to reproduce.
B) The patient will require a vaccination to prevent the bacteria from reproducing.
C) The patient’s immune system will produce antibodies that prevent the bacteria’s reproduction.
D) The medication may serve as an energy source and cause rapid reproduction of the bacteria.
A) The bacteria may develop resistance to the medication and continue to reproduce.
Which substance must be present to release energy from glucose?
A) hydrogen
B) oxygen
C) lactic acid
D) carbon dioxide
B) Oxygen
What would most likely occur if a new insect species were introduced into North Carolina’s ecosystems?
A) The new insect species would maintain the stability of the area.
B) The new insect species would have less reproductive success.
C) The new insect species would be eaten by natural predators.
D) The new insect species would increase competition for food resources.
D) The new insect species would increase competition for food resources.
How could a scientist best determine whether a fungus is a new species?
A) by comparing the physical appearance of the fungus to a known fungal species
B) by comparing the epidermal cells of the fungus to a known fungal species
C) by comparing the feeding habits of the fungus to a known fungal species
D) by comparing the DNA sequence of the fungus to a known fungal species
D) by comparing the DNA sequence of the fungus to a known fungal species
A nuclear membrane with pores surrounds a cell’s nucleus. How would a nucleus that lacks pores affect its function in the cell?
A) Messenger RNA would not be able to leave the nucleus to provide the code to make proteins.
B) Messenger RNA would not be able to leave the nucleus to make carbohydrates.
C) DNA would not be able to leave the nucleus to be used to make proteins.
D) DNA would not be able to replicate or leave the nucleus.
A) Messenger RNA would not be able to leave the nucleus to provide the code to make proteins.
Among birds, some skin cells grow feathers when they mature, while other skin cells grow scales at maturity. Which statement best explains this difference?
A) Skin cells exposed to colder environments grow feathers, while skin cells exposed to wet environments grow scales.
B) While all cells have the same DNA, specialized cells express certain traits that produce feathers or scales.
C) Skin cells that have feathers are diploid, while skin cells that make scales are haploid.
D) Some skin cells have different DNA to build structures like feathers and scales.
B) While all cells have the same DNA, specialized cells express certain traits that produce feathers or scales.
Which is an example of the cycling of carbon?
A) Animals use the carbon in carbon dioxide for cellular respiration.
B) Graphene is formed by causing carbon atoms to align in a particular way.
C) Carbon dioxide is trapped in the atmosphere and contributes to the greenhouse effect.
D) A plant uses the carbon in carbon dioxide for photosynthesis and is eaten by an animal.
D) A plant uses the carbon in carbon dioxide for photosynthesis and is eaten by an animal.
Which human action could best reduce global climate change?
A) increasing the ozone layer
B) converting to carbon-free energy
C) monitoring smog levels in urban areas
D) protecting fresh water against pollution
B) converting to carbon-free energy
Which information provides the most reliable evidence of common ancestry for four species of mammals?
A) embryological forms
B) nucleotide sequences
C) anatomical structures
D) homologous structures
B) nucleotide sequences
A cell experiences an error during the cell cycle, causing it to go through cytokinesis before mitosis. Which statement best describes the new cells?
A) The new cells will be double the size of the original cell.
B) The new cells will have twice as much DNA as the original cell.
C) The new cells will have no DNA or organelles but will continue progressing through the cell cycle.
D) The new cells will have an incorrect amount of DNA and organelles, and will likely experience cell death
D. The new cells will have an incorrect amount of DNA and organelles and will likely experience cell death.
A student crosses two plants.
Plant 1 has red petals (RR).
Plant 2 has white petals (WW).
All of the offspring plants have pink petals (RW).
Which type of inheritance do these plants exhibit?
A) polygenic
B) codominant
C) incompletely dominant
D) autosomal recessive
C) incompletely dominant
Which statement best explains the relationship between glucose, cellular respiration, and photosynthesis?
A) Photosynthesis uses the glucose produced by cellular respiration to make energy.
B) Photosynthesis and cellular respiration are both used to produce glucose and energy.
C) Photosynthesis produces the glucose used in cellular respiration to make energy.
D) Photosynthesis and cellular respiration both consume glucose to produce energy.
C) Photosynthesis produces the glucose used in cellular respiration to make energy.
How would a longer snow season most likely affect the populations of red and white foxes living in the same forest ecosystem?
A) Red foxes would have a greater advantage, so their population size would increase, while the white fox population size would decrease.
B) White foxes would have a greater advantage, so their population size would increase, while the red fox population size would decrease.
C) White foxes would have a lesser advantage, so their population size would increase, while the red fox population size would remain the same.
D) Red foxes would have a lesser advantage, so their population size would increase, while the white fox population size would remain the same
B) White foxes would have a greater advantage, so their population size would increase, while the red fox population size would decrease.
Which base pairs with adenine in a DNA molecule?
C) Thymine
Which of the following structures is found in plant cells but not animal cells?
C) chloroplast
How might mutations contribute to natural selection?
A) They occur after a natural disaster has changed a population’s environment.
B) They result when organisms observe traits of other successful populations.
C) They occur in somatic cells and can be passed to offspring.
D) They add variations to the gene pool of a population
D) They add variations to the gene pool of a population
The plants in an ecosystem complete both photosynthesis and cellular respiration. How do the two processes differ from one another in terms of energy?
A) Photosynthesis stores solar energy in the chemical bonds of carbohydrates, while cellular respiration releases energy from the chemical bonds in carbohydrates to produce ATP molecules.
B) Photosynthesis releases energy from the chemical bonds in carbohydrates to produce ATP molecules, while cellular respiration stores solar energy in the chemical bonds of carbohydrates.
C) Photosynthesis stores solar energy in ATP molecules for cellular use, while cellular respiration produces ATP by breaking inorganic chemical bonds.
D) Photosynthesis stores solar energy in high-energy chemical bonds of inorganic compounds, while cellular respiration releases solar energy to heat cellular structures
A) Photosynthesis stores solar energy in the chemical bonds of carbohydrates, while cellular respiration releases energy from the chemical bonds in carbohydrates to produce ATP molecules.
An animal was cloned in a lab, producing five genetically identical offspring. The offspring were then sent to five different zoos. After five years, scientists collected data on these animals and found a variation in their heights. What is the most likely explanation for the data?
A) Each clone experienced mutations with no effect on its genes.
B) Each clone experienced a different environment with no effect on its genes.
C) Each clone experienced the same mutations, which influenced the expression of its genes.
D) Each clone experienced a different environment, which influenced the expression of its genes.
D) Each clone experienced a different environment, which influenced the expression of its genes.
How is a DNA molecule arranged?
A) double-stranded with alternating deoxyribose and phosphate groups on the sides with adenine, guanine, cytosine, and thymine in the middle
B) double-stranded with alternating deoxyribose and phosphate groups on the sides with adenine, guanine, cytosine, and uracil in the middle
C) double-stranded with alternating ribose and phosphate groups on the sides with adenine, guanine, cytosine, and thymine in the middle
D) double-stranded with alternating ribose and phosphate groups on the sides with adenine, guanine, cytosine, and uracil in the middle
A) double-stranded with alternating deoxyribose and phosphate groups on the sides with adenine, guanine, cytosine, and thymine in the middle
Which process describes the movement of molecules from an area of low concentration to an area of high concentration using energy?
C) Active transport
Modern dairy cows are different from their ancestors. They produce larger volumes of milk with higher protein and fat content. Which statement best explains this?
A) Dairy cows within the species have interbred, resulting in low genetic diversity among offspring.
B) Dairy cows within the species have interbred, resulting in high genetic diversity among offspring.
C) Humans have used artificial selection to encourage transmission of traits associated with high-quality milk production from parent cows to offspring.
D) Humans have used natural selection to encourage transmission of traits associated with high-quality milk production from parent cows to offspring
C) Humans have used artificial selection to encourage transmission of traits associated with high-quality milk production from parent cows to offspring.
What is the primary purpose of cellular respiration?
B) to store energy in the form of ATP
How can genetic mutations contribute to an organism's adaptability?
A) By introducing new traits that may help the organism survive in changing environments