molecules
What are the six elements that make up living organisms?
C, H, N, O, P, S
In guinea pigs, the allele for black hair (B) is dominant to the allele for brown hair (b). Two black-haired guinea pigs are crossed. One of the guinea pigs is homozygous for black hair and one is heterozygous.What percentage of the offspring are expected to have black hair?
A.
25%
B.
50%
C.
75%
D.
100%
D.
100%
Which of the following provides the most convincing evidence that two different animal species evolved from a common ancestor?
They live in similar environments.
They have similar adult body shapes.
They have similar methods of locomotion.
They show similar features in embryonic development.
They show similar features in embryonic development.
Wolves were reintroduced into Yellowstone National Park in 1995. Wolves hunt elk, but the elk population in the park has declined more than it was expected to decline from direct predation by wolves. Other than direct predation, which of the following factors most likely contributed to the decline in the elk population?
decreased birth rate in elk
decreased emigration of elk
decreased parasite load in elk
decreased competition between elk
decreased birth rate in elk
Resistance to antibiotics results from variations in the genetic code of Streptococcus pneumoniae. Which type of molecule encodes genetic information in Streptococcus pneumoniae?
A. carbohydrate B. fatty acid C. nucleic acid D. protein
C. nucleic acid
In a molecule of double-stranded DNA, the amount of adenine present is always equal to the amount of
A. cytosine
B. guanine
C. thymine
D. uracil
C. thymine
Which of the following is most important in classifying two groups of bears into the same genus?
A. similar diets B. similar genes C. similar habitat D. similar body size
B. similar genes
The willow flycatcher is a bird species with a summer range throughout much of the United States. Which of the following would directly decrease the size of a willow flycatcher population in a given year?
the disappearance of a species that preys on willow flycatchers
the arrival of migrating willow flycatchers from populations in other areas
the emigration of male willow flycatchers that did not secure territories
the hatching of a larger percentage of eggs in the willow flycatcher population
the emigration of male willow flycatchers that did not secure territories
Secretions from the pancreas contain compounds called lipases. Lipases increase the rate of digestion of lipids.
Lipases are an example of which of the following?
A.
enzymes
B.
hormones
C.
nucleic acids
D.
simple sugars
enzymes
A single nucleotide of DNA is composed of which of the following substances?
adenine, guanine, and cytosine
hydrogen, a phosphate group, and adenine
ribose sugar, deoxyribose sugar, and thymine
deoxyribose sugar, a phosphate group, and a nitrogenous base
deoxyribose sugar, a phosphate group, and a nitrogenous base
Some lizards have an adaptation that allows their tails to break off with minimal damage to bones, nerves, blood vessels, and muscles. This type of lizard can then regrow the missing portion of the tail. Which of the following statements best explains why this adaptation is selected for in lizard populations?
Lizards with this adaptation are better at climbing trees.
Lizards with this adaptation are more likely to escape from predators.
Lizards with this adaptation can use their tails as lures to attract more food.
Lizards with this adaptation can camouflage themselves more easily in vegetation
Lizards with this adaptation are more likely to escape from predators.
An invasive species of green algae has become established along the coasts of the Mediterranean Sea. Which of the following statements best explains why this species of algae has been so successful in the Mediterranean Sea?
It is not a good competitor.
It is not eaten by many animals.
It reproduces slowly in warm waters.
It requires more nutrients than most other algae.
It is not eaten by many animals.
.Which of the following matches a cell organelle with its function?
Chloroplast- movement
C. nucleus- cell regulation
vacuole- energy production
D. mitochondrion- photosynthesis
C. nucleus- cell regulation
Which of the following processes produces the nucleotide sequence UUA from the sequence AAT?
A. meiosis
B. respiration
C. replication
D. transcription
D. transcription
A species of ivy invades the beetles’ current habitat and becomes the dominant form of vegetation. The color of the ivy’s leaves is similar to the beetles’ average color. Considering selective pressure on the beetles from predatory birds, which type of natural selection will most likely occur in this situation?
disruptive
stabilizing
directional toward dark body color
directional toward light body color
stabilizing
How much energy is passed on from one trophic level to the next? Why?
10%
Iodine is moved against its concentration gradient into the cells of the thyroid gland. Iodine is used by the thyroid cells to produce a hormone.Which of the following processes moves iodine into the thyroid cells?
A.
active transport
B.
cellular respiration
C.
diffusion
D.
osmosis
active transport
Which type of cell must contain a mutation in order for the mutation to be passed from a woman to her offspring?
A. blood cell B. brain cell C. egg cell D. skin cell
C. egg cell
The scientific name for the woodchuck is Marmota monax, and the scientific name for the long-tailed marmot is Marmota caudata. Which of the following statements describes the taxonomic relationship between the woodchuck and the long-tailed marmot?
They belong to different phyla.
They belong to the same genus.
They belong to the same species.
They belong to different families.
They belong to the same genus.
Explain how decomposers support an ecosystem.
They break apart dead organisms into simpler inorganic materials, making nutrients available to primary producers.