Cells
The process by which the order of bases in messenger RNA (mRNA) codes for the order of amino acids in a protein is called
A translation
B transcription
C replication
D nondisjunction
A translation
The gene for red/green colorblindness in humans is recessive and primarily affects males. It must be located on
A the X chromosome
B the Y chromosome
C both the X and Y chromosomes
D either the X or Y chromosome
A the X chromosome
Fungi and bacteria that live on dead matter are classified as
A. parasites
B. Carnivores
C. omnivores
D. saprophytes
D. saprophytes
Geographic isolation caused the separation of rainforest frog populations into a population in the north and a population in the south. The separated populations later reconnected because the climate became wetter and warmer, causing the rainforest to expand. When males from the north mated with females from the south, the offspring failed to develop past the tadpole stage. When males from the south mated with females from the north, the offspring developed more slowly than the offspring of pairs of northern frogs. Based on these data, which event occurred while the two populations of frogs were separated?
A. The two populations developed into new species.
B. The two populations mated with other species of frogs.
C. The two populations began a new method of reproduction.
D. The two populations had fewer offspring than before the separation.
A. The two populations developed into new species.
Predators often feed on weak or sick animals in an ecosystem. The role of the predator is described as its
A community
B habitat
C niche
D population
C niche
Athletes are often concerned with the question of how much protein they need in their diets because of the requirement of growing muscles for protein. Just as muscles need the basic building block of protein, protein itself has basic building blocks also. Which of the following are the basic building blocks of protein?
A nitrates
B amino acids
C monosaccharides
D nucleotides
B amino acids
Pea plants have seeds that are either round or wrinkled. In the cross RR x Rr, what will be the phenotypic ratio of the offspring? R = Round Seeds, r = Wrinkled Seeds
A 50% RR and 50% Rr
B 25% RR, 50% Rr, and 25% rr
C 50% round seeds and 50% wrinkled seeds
D 100% round seeds
D 100% round seeds
Some viral diseases require only one vaccination, which lasts for years. For other diseases like the flu, vaccinations last only one season. The flu vaccine lasts such a short time because the flu virus
A is more easily transmitted
B mutates much more rapidly
C is less dangerous
D is much smaller
B mutates much more rapidly
Which statement describes the best evidence that two species share a recent common ancestor?
A. The species are about the same size
B. The species eat the same type of food
C. The species live in the same ecosystem
D. The species have similar DNA sequences
D. The species have similar DNA sequences
Organisms in an ecosystem are linked together by
A geochemical pathways
B greenhouse effects
C food webs
D water cycles
C food webs
If placed in a hypertonic solution, a plant cell will
A swell
B burst
C shrink in size
D remain constant in size
C shrink in size
The genetic disorder trisomy 21 (Down syndrome) is caused by what genetic event?
A crossing-over
B nondisjunction
C base pair substitution
D frame-shift location
B nondisjunction
Which is a characteristic of DDT in the food web?
A. the highest concentration of DDT is located at the producer level
B. DDT tends to decrease in concentration as it is transferred from primary consumer to secondary consumer
C. the lowest concentrations of DDT are located in birds
D. DDT tends to increase in concentration as it is transferred from producer to consumer
D. DDT tends to increase in concentration as it is transferred from producer to consumer
Fossils of snakes with hind limbs but no forelimbs have been discovered. Which of the following conclusions is best supported by this fossil evidence?
A. Snakes are likely to evolve limbs in the future
B. Snakes are well adapted to live on land without limbs
C. Snakes have evolved from an ancestral reptile with limbs
D. Snakes are poor competitors compared to reptiles with limbs
C. Snakes have evolved from an ancestral reptile with limbs
The biome populated by cone-bearing trees such as pine, spruce, and fir is the
A deciduous forest
B coniferous forest
C savanna
D tundra
B coniferous forest
In glycolysis, the first stage of cellular respiration, ATP molecules are produced. What is the net gain of ATP molecules (per molecule of glucose) from glycolysis?
A 1
B 2
C 4
D 36
B 2
A male and female have a child that has three copies of chromosome 18. Although both parents are unaffected, their doctor claims that the disorder associated with having an extra chromosome 18 is the result of a chromosomal mutation in cells that carry inherited material. Which argument supports this claim?
A. A mutation occurred when crossing over caused chromosome 18 to be replicated twice during meiosis, allowing one parent to donate two copies of chromosome 18 to the child.
B. A nondisjunction mutation was caused by the improper separation of the genetic material during meiosis, allowing the gamete of one parent to donate two copies of chromosome 18 to the child.
C. A substitution mutation during replication allowed the genetic material of chromosome 18 to replace the genetic material of a nearby chromosome, causing the child to have three copies of chromosome 18.
D. An insertion mutation during replication allowed the genetic material of chromosome 18 to be inserted into the genetic material of another chromosome, causing three copies of chromosome 18 to be made.
B. A nondisjunction mutation was caused by the improper separation of the genetic material during meiosis, allowing the gamete of one parent to donate two copies of chromosome 18 to the child.
Fungi have filamentous bodies, are heterotrophic, and have cell walls that contain chitin. Which of these are examples of fungi?
A bacteria
B molds
C algae
D amoebas
B molds
According to scientists, donkeys and horses share a common ancestor. Which evidence shows that the two organisms are related?
A. Both are tall
B. Both run fast
C. They have the same diet
D. They have the same bones in their limbs
D. They have the same bones in their limbs
Which of the following practices is MOST likely to slow the buildup of CO2 in the atmosphere?
A increased use of tropical rain forest areas for agriculture
B increased use of genetically engineered plants
C decreased pesticide use in favor of biological controls
D decreased use of fossil fuels
D decreased use of fossil fuels
Hemoglobin is a protein found in the red blood cells of vertebrates and in the plasma of many invertebrates. The function of this protein is to transport oxygen throughout the body and to bring carbon dioxide back to be expelled from the organism. If the amino acid sequence of the protein is altered, the mutated protein is not as efficient at carrying oxygen as is the normal hemoglobin. Which argument is supported by this information?
A. The mutated hemoglobin protein can still carry carbon dioxide to be expelled from the organism.
B. Hemoglobin must be a simple molecule because it is found in both vertebrates and invertebrates.
C. Structural changes of hemoglobin affect its ability to carry oxygen, indicating that the shape of a protein is important to its function.
D. Normal hemoglobin must be a larger molecule than the mutated hemoglobin since it has sufficient space to attach to and carry both oxygen molecules and carbon dioxide molecules.
C. Structural changes of hemoglobin affect its ability to carry oxygen, indicating that the shape of a protein is important to its function.
Which are two factors that change gene frequencies in a population?
A. no mutations and large populations
B. no migration and no mutations
C. Large populations and random mating
D. mutations and nonrandom mating
D. mutations and nonrandom mating
Unlike the plant cell walls, the bacterial cell wall is made of which of the following?
A cellulose and starches
B chitin and fats
C sugars and amino acids
D cellulose and sugars
C sugars and amino acids
The ribosome of the bacterium E. coli includes the ribosomal protein L4 (rpl4). The rpl4 gene carries the instructions for making rpl4 protein. Which of the following arguments provides support for the claim that E. coli has a common ancestor with all other organisms?
A. Every organism depends on proteins to carry out essential cellular processes. Ribosomes are needed by all organisms to synthesize proteins such as rpl4.
B. Every organism possesses in its ribosome a protein that is similar to rpl4. This protein has an amino acid sequence that is similar to the sequence of E. coli’s rpl4.
C. Every organism contains a structure that is similar to a ribosome. This structure helps convert the instructions from the rpl4 gene into amino acids.
D. Every organism has proteins made of amino acids. The code for amino acids is the same in E. coli because the instructions for amino acids come from the DNA. DNA contains the same components in all organisms.
B. Every organism possesses in its ribosome a protein that is similar to rpl4. This protein has an amino acid sequence that is similar to the sequence of E. coli’s rpl4.
Ruby-throated hummingbirds are found throughout eastern North America. They are omnivores, feeding on nectar, pollen, tree sap, insects, and spiders. They get all the water they need from nectar. Most nests are in forested areas, citrus groves, marshes, and scrubland. The hummingbirds breed in the spring and the summer, and females raise one to three broods per breeding season. Most of the hummingbirds migrate to Mexico or Central America for the winter. Many fly nonstop for 20 hours to cross the Gulf of Mexico. However, increasing numbers of the hummingbirds have begun to winter north of the gulf. Researchers have documented that the hummingbirds’ winter range has expanded northward by about 300 kilometers in recent years. Which explanation BEST predicts the ability of the hummingbirds to survive their first winter in this new environment?
A. Finding suitable nesting materials and sites is the most important task the hummingbirds must accomplish because they must produce offspring.
B. Finding a sufficient supply of flowering plants, flowering trees, and insects is the most important task for the hummingbirds because they need food to survive.
C. Finding bodies of water is the most important task for the hummingbirds because they need to supplement the supply of nectar if it is inadequate to provide all the calories the hummingbirds need to survive.
D. Finding mates to allow the hummingbirds to lay fertile eggs and have two parents to feed the new hatchlings is the most important task for the hummingbirds because they need to ensure there is a new generation of hummingbirds in the region.
B. Finding a sufficient supply of flowering plants, flowering trees, and insects is the most important task for the humming birds because they need food to survive.