LEAP 2025 Biology Practice Test
Study online at https://quizlet.com/_f5zx6v
1. Which claim is supported by C. The number of eggs and the mass of
the information in Graph 1 and the eggs produced by sockeye salmon
Graph 2? depend on the amount of matter stored by
A. The mass of the eggs and the female.
the number of eggs produced
by sockeye salmon are indepen-
dent of the females mass.
B. The mass of the eggs pro-
duced by sockeye salmon de-
pends on the female's average
age at reproduction, but the
number of eggs does not.
C. The number of eggs and the
mass of the eggs produced by
sockeye salmon depend on the
amount of matter stored by the
female.
D. The number of eggs produced
by sockeye salmon decreases
with female body length, but the
mass of the eggs does not.
2. Develop a model that can be 1. Sperm fertilizes egg.
used to explain the stages of 2. Genetic material is evenly divided.
growth and development that re- 3. Embryo changes from two to four cells.
sult in a salmon fry. 4. Cells differentiate.
5. Specialized tissues and organs are pro-
duced.
3. Chum salmon fry average 3.8 cm Based on the information in Graph 3,
in length, compared to 3 cm for chum salmon fry are likely to eat prey
pink salmon fry and 10 cm for that is larger than prey eaten by the pink
coho salmon fry. salmon fry and smaller than prey eaten by
Based on the information in the coho salmon fry. This is because as a
Graph 3, chum salmon fry are salmon's size increases, its matter intake
likely to eat prey that is ______ needs increase.
prey eaten by the pink salmon
fry and ______ prey eaten by the
coho salmon fry. This is because
, LEAP 2025 Biology Practice Test
Study online at https://quizlet.com/_f5zx6v
as a salmon's size increases, its
matter intake needs ______.
4. Which statement best explains C. Salmon break bonds in complex food
how salmon obtain and use mat- molecules to release the carbon, oxygen,
ter to support their biological and hydrogen atoms needed for the for-
functions? mation of other molecules.
A. Salmon use complex, car-
bon-based molecules obtained
directly from seawater and the
atmosphere to produce other
complex molecules, such as
fats.
B. Salmon use the carbon, hy-
drogen, and oxygen atoms ob-
tained directly from seawater
and the atmosphere to form sug-
ars and proteins.
C. Salmon break bonds in com-
plex food molecules to release
the carbon, oxygen, and hydro-
gen atoms needed for the forma-
tion of other molecules.
D. Salmon break down carbon,
hydrogen, and oxygen atoms ob-
tained from food into smaller, en-
ergy-rich elements.
5. Which claim is best supported C. Changes in placodes over time allowed
by the information about scales for the development of different struc-
and feathers? tures.
A. The presence or absence of
placodes determines whether an
organism develops feathers or
scales.
B. All vertebrates evolved direct-
ly from a common ancestor that
had feathers.
C. Changes in placodes over
, LEAP 2025 Biology Practice Test
Study online at https://quizlet.com/_f5zx6v
time allowed for the develop-
ment of different structures.
D. Placodes evolved directly
from mutations that result in the
growth of scales.
6. Part A Part A
Which statement best explains A. A mutation in DNA affected the types of
what caused some theropods to proteins produced by placodes.
develop feathers?
A. A mutation in DNA affected Part B
the types of proteins produced A. The DNA of modern-day vertebrates
by placodes. codes for the proteins in placodes.
B. A protein in the placodes
caused a mutation in the gene
that produces feathers.
C. A mutation in the placode
gene caused placodes to pro-
duce different DNA.
D. A mutation in DNA caused the
placodes that control genes to
grow feathers.
Part B
Which information is evidence
that best supports the answer to
Part A?
A. The DNA of modern-day verte-
brates codes for the proteins in
placodes.
B. All vertebrate embryos have
the same genetic mutations in
their placode DNA.
C. Placodes in all modern-day
embryos contain the same num-
ber of mutations.
D. A single placode can sponta-
neously develop into any type of
body covering.
Study online at https://quizlet.com/_f5zx6v
1. Which claim is supported by C. The number of eggs and the mass of
the information in Graph 1 and the eggs produced by sockeye salmon
Graph 2? depend on the amount of matter stored by
A. The mass of the eggs and the female.
the number of eggs produced
by sockeye salmon are indepen-
dent of the females mass.
B. The mass of the eggs pro-
duced by sockeye salmon de-
pends on the female's average
age at reproduction, but the
number of eggs does not.
C. The number of eggs and the
mass of the eggs produced by
sockeye salmon depend on the
amount of matter stored by the
female.
D. The number of eggs produced
by sockeye salmon decreases
with female body length, but the
mass of the eggs does not.
2. Develop a model that can be 1. Sperm fertilizes egg.
used to explain the stages of 2. Genetic material is evenly divided.
growth and development that re- 3. Embryo changes from two to four cells.
sult in a salmon fry. 4. Cells differentiate.
5. Specialized tissues and organs are pro-
duced.
3. Chum salmon fry average 3.8 cm Based on the information in Graph 3,
in length, compared to 3 cm for chum salmon fry are likely to eat prey
pink salmon fry and 10 cm for that is larger than prey eaten by the pink
coho salmon fry. salmon fry and smaller than prey eaten by
Based on the information in the coho salmon fry. This is because as a
Graph 3, chum salmon fry are salmon's size increases, its matter intake
likely to eat prey that is ______ needs increase.
prey eaten by the pink salmon
fry and ______ prey eaten by the
coho salmon fry. This is because
, LEAP 2025 Biology Practice Test
Study online at https://quizlet.com/_f5zx6v
as a salmon's size increases, its
matter intake needs ______.
4. Which statement best explains C. Salmon break bonds in complex food
how salmon obtain and use mat- molecules to release the carbon, oxygen,
ter to support their biological and hydrogen atoms needed for the for-
functions? mation of other molecules.
A. Salmon use complex, car-
bon-based molecules obtained
directly from seawater and the
atmosphere to produce other
complex molecules, such as
fats.
B. Salmon use the carbon, hy-
drogen, and oxygen atoms ob-
tained directly from seawater
and the atmosphere to form sug-
ars and proteins.
C. Salmon break bonds in com-
plex food molecules to release
the carbon, oxygen, and hydro-
gen atoms needed for the forma-
tion of other molecules.
D. Salmon break down carbon,
hydrogen, and oxygen atoms ob-
tained from food into smaller, en-
ergy-rich elements.
5. Which claim is best supported C. Changes in placodes over time allowed
by the information about scales for the development of different struc-
and feathers? tures.
A. The presence or absence of
placodes determines whether an
organism develops feathers or
scales.
B. All vertebrates evolved direct-
ly from a common ancestor that
had feathers.
C. Changes in placodes over
, LEAP 2025 Biology Practice Test
Study online at https://quizlet.com/_f5zx6v
time allowed for the develop-
ment of different structures.
D. Placodes evolved directly
from mutations that result in the
growth of scales.
6. Part A Part A
Which statement best explains A. A mutation in DNA affected the types of
what caused some theropods to proteins produced by placodes.
develop feathers?
A. A mutation in DNA affected Part B
the types of proteins produced A. The DNA of modern-day vertebrates
by placodes. codes for the proteins in placodes.
B. A protein in the placodes
caused a mutation in the gene
that produces feathers.
C. A mutation in the placode
gene caused placodes to pro-
duce different DNA.
D. A mutation in DNA caused the
placodes that control genes to
grow feathers.
Part B
Which information is evidence
that best supports the answer to
Part A?
A. The DNA of modern-day verte-
brates codes for the proteins in
placodes.
B. All vertebrate embryos have
the same genetic mutations in
their placode DNA.
C. Placodes in all modern-day
embryos contain the same num-
ber of mutations.
D. A single placode can sponta-
neously develop into any type of
body covering.
