ACT Science Review
Questions + correct answers
CORRECT!!!
The correct answer is Uracil. Uracil is one of the four nitrogenous bases
found in RNA. The other three nitrogenous bases in RNA are also found in
DNA, but uracil is not found in DNA. - answer ✅✅Nitrogenous base that
occurs in RNA but not in DNA
(A) Deoxyribose
(B) Ribose
(C) Uracil
(D) Cytosine
(E) Thymine
The correct answer is cytosine. The only base that is always found in equal
quantities with guanine is its complement, cytosine (recall that the
nitrogenous bases in DNA pair, A with T and C with G.) - answer ✅✅A
nitrogenous base that occurs in DNA in equal quantities with guanine
(A) Deoxyribose
(B) Ribose
(C) Uracil
(D) Cytosine
(E) Thymine
,The correct answer is succession. Within a given area, the vegetation
changes over time, tending towards the climax type of vegetation for that
particular area. (Repeated disturbances, of course, interrupt this process,
and may in effect reset the clock, so that succession begins anew.) - answer
✅✅The change in plant types inhabiting an area over time, resulting in a
climax community
(A) Succession
(B) Dispersion
(C) Fertilization
(D) Speciation
(E) Mutation
The correct answer is speciation. Recall that the functional definition of a
species is a group of organisms that can interbreed with each other but do
not interbreed with others. The inability to interbreed after long separation is
a sign that speciation has occurred; the two populations now represent two
different species. - answer ✅✅The inability of two populations to interbreed
after being separated by a barrier for a long period of time
(A) Succession
(B) Dispersion
(C) Fertilization
(D) Speciation
(E) Mutation
The correct answer is succession. This is a specific example of succession,
the gradual filling in of a wetland to become a meadow or a forest. - answer
✅✅Plants growing in and around a pond eventually filling in the pond and
changing it to a terrestrial habitat
(A) Succession
(B) Dispersion
(C) Fertilization
(D) Speciation
, (E) Mutation
The correct answer is Producers (e.g., grasses). Organisms that comprise the
greatest biomass in a terrestrial food chain are the producers. Net
productivity (photosynthesis minus respiration) creates biomass. - answer
✅✅Organisms that comprise the greatest mass of living substance
(biomass) in a terrestrial food chain
(A) Decomposers (e.g., bacteria)
(B) Producers (e.g., grasses)
(C) Primary consumers (e.g., mice)
(D) Secondary consumers (e.g., snakes)
(E) Tertiary consumers (e.g., hawks)
The correct answer is Decomposers (e.g., bacteria). Of the list of organisms
given, decomposer bacteria are the only ones that can covert nitrogen-
containing organic molecules into ammonia. Ammonia, which is a form of
nitrogen-containing molecule, is subsequently converted to nitrate that
plants can use to synthesize new organic compounds with nitrifying bacteria.
- answer ✅✅Organisms that convert nitrogen-containing organic molecules
into nitrates
(A) Decomposers (e.g., bacteria)
(B) Producers (e.g., grasses)
(C) Primary consumers (e.g., mice)
(D) Secondary consumers (e.g., snakes)
(E) Tertiary consumers (e.g., hawks)
The correct answer is 7.4. The question gives you the information that blood
is slightly basic. 10.6 is very basic (recall that pH is a logarithmic scale), 7.0
is neutral, 6.4 is slightly acid, and of course 4.6 is the most acid of the five
choices. - answer ✅✅The pH of human blood is slightly basic. Which of the
following is most likely to be the pH of human blood?
(A)
(B)
Questions + correct answers
CORRECT!!!
The correct answer is Uracil. Uracil is one of the four nitrogenous bases
found in RNA. The other three nitrogenous bases in RNA are also found in
DNA, but uracil is not found in DNA. - answer ✅✅Nitrogenous base that
occurs in RNA but not in DNA
(A) Deoxyribose
(B) Ribose
(C) Uracil
(D) Cytosine
(E) Thymine
The correct answer is cytosine. The only base that is always found in equal
quantities with guanine is its complement, cytosine (recall that the
nitrogenous bases in DNA pair, A with T and C with G.) - answer ✅✅A
nitrogenous base that occurs in DNA in equal quantities with guanine
(A) Deoxyribose
(B) Ribose
(C) Uracil
(D) Cytosine
(E) Thymine
,The correct answer is succession. Within a given area, the vegetation
changes over time, tending towards the climax type of vegetation for that
particular area. (Repeated disturbances, of course, interrupt this process,
and may in effect reset the clock, so that succession begins anew.) - answer
✅✅The change in plant types inhabiting an area over time, resulting in a
climax community
(A) Succession
(B) Dispersion
(C) Fertilization
(D) Speciation
(E) Mutation
The correct answer is speciation. Recall that the functional definition of a
species is a group of organisms that can interbreed with each other but do
not interbreed with others. The inability to interbreed after long separation is
a sign that speciation has occurred; the two populations now represent two
different species. - answer ✅✅The inability of two populations to interbreed
after being separated by a barrier for a long period of time
(A) Succession
(B) Dispersion
(C) Fertilization
(D) Speciation
(E) Mutation
The correct answer is succession. This is a specific example of succession,
the gradual filling in of a wetland to become a meadow or a forest. - answer
✅✅Plants growing in and around a pond eventually filling in the pond and
changing it to a terrestrial habitat
(A) Succession
(B) Dispersion
(C) Fertilization
(D) Speciation
, (E) Mutation
The correct answer is Producers (e.g., grasses). Organisms that comprise the
greatest biomass in a terrestrial food chain are the producers. Net
productivity (photosynthesis minus respiration) creates biomass. - answer
✅✅Organisms that comprise the greatest mass of living substance
(biomass) in a terrestrial food chain
(A) Decomposers (e.g., bacteria)
(B) Producers (e.g., grasses)
(C) Primary consumers (e.g., mice)
(D) Secondary consumers (e.g., snakes)
(E) Tertiary consumers (e.g., hawks)
The correct answer is Decomposers (e.g., bacteria). Of the list of organisms
given, decomposer bacteria are the only ones that can covert nitrogen-
containing organic molecules into ammonia. Ammonia, which is a form of
nitrogen-containing molecule, is subsequently converted to nitrate that
plants can use to synthesize new organic compounds with nitrifying bacteria.
- answer ✅✅Organisms that convert nitrogen-containing organic molecules
into nitrates
(A) Decomposers (e.g., bacteria)
(B) Producers (e.g., grasses)
(C) Primary consumers (e.g., mice)
(D) Secondary consumers (e.g., snakes)
(E) Tertiary consumers (e.g., hawks)
The correct answer is 7.4. The question gives you the information that blood
is slightly basic. 10.6 is very basic (recall that pH is a logarithmic scale), 7.0
is neutral, 6.4 is slightly acid, and of course 4.6 is the most acid of the five
choices. - answer ✅✅The pH of human blood is slightly basic. Which of the
following is most likely to be the pH of human blood?
(A)
(B)
