In most energy pyramids, what is the original source of energy for all the organisms?
sunlight
Which statement about enzymes is true?
Enzymes have an active site that has a complementary shape to a substrate.
Which statement is true about mitosis and meiosis?
Daughter cells formed by mitosis and meiosis are similar to the parent cell.
Daughter cells formed by mitosis and meiosis are different from the parent cell.
Asexual reproduction involves mitosis while sexual reproduction involves meiosis.
Sexual reproduction involves mitosis while asexual reproduction involves meiosis.
Asexual reproduction involves mitosis while sexual reproduction involves meiosis.
A section of DNA codes for the sequence of nitrogenous bases of mRNA to initiate protein synthesis as shown.
What is the process involved in the coding?
replication
transcription
transduction
Translation
transcription
Which factor can increase the chances of a species evolving by natural selection?
high reproductive rate
no related species
stable environmental conditions
small gene pool
high reproductive rate
Which factor is known to influence climate change?
global warming
What type of macromolecules are enzymes?
proteins
Which statement best distinguishes meiosis from mitosis?
Meiosis replicates then separates genetic information.
Meiosis combines the genetic information of egg and sperm.
Meiosis maintains the cell’s original chromosome number.
Meiosis reduces the cell’s original chromosome number by half.
Meiosis reduces the cell’s original chromosome number by half.
An error occurring during the process of protein synthesis can result in a mutation. Which summary best explains the events that must occur for this new trait to be expressed.
First, there is a change in the sequence of nucleotides, then the formation of a protein, then the expression of the trait, and finally, the joining of amino acids.
First, there is a change in the sequence of nucleotides, then the joining of amino acids, then the formation of a protein, and finally, the expression of the trait.
First, there is the joining of amino acids, then the formation of a protein, then the change in the sequence of nucleotides, and finally, the expression of the trait.
First, there is the expression of the trait, then the change in the sequence of nucleotides, then the joining of amino acids, and finally, the formation of the protein.
First, there is the joining of amino acids, then the formation of a protein, then the change in the sequence of nucleotides, and finally, the expression of the trait.
Bats and birds are only very distantly related, and both evolved wings for flight in very different evolutionary pathways. What is the term that describes the wing structures that these species evolved?
analogous structures
divergent structures
embryonic structures
homologous structures
analogous structures
Which example best illustrates organisms' dependence on abiotic factors?
Tree ferns compete for sunlight in the forest.
Which statement is true about the differentiated cells in an organism?
Differentiated cells have the same DNA, but they do not activate all parts of their DNA.
Blood type is determined by multiple alleles. A woman with type O blood marries a man who is heterozygous for type B blood. What is the probability that their first child will have type AB blood
0%
25%
50%
75%
0%
DNA nucleotides ultimately code for the production of proteins in cells.
Using this codon chart as a guide, what amino acid sequence would be produced by ribosomes based on a DNA sequence of AAA GCC CGA?
glycine - isoleucine - stop
lysine - alanine - arginine
phenylalanine - arginine - alanine
proline - stop - isoleucine
phenylalanine - arginine - alanine
Vaccines stimulate the immune system to develop immunity to pathogens such as viruses. Why do researchers have to create new vaccines each year?
Viruses mutate to adapt and survive
Viruses use host cells to reproduce
Viruses vary in their shapes and complexity
Viruses have protein coats that protect their DNA or RNA.
Viruses mutate to adapt and survive
How does the carbon dioxide in the atmosphere become incorporated as carbon into living things?
through photosynthesis
Some cellular processes require building a high concentration of molecules on one side of the cell membrane. What method would a cell use to move molecules to an area where the molecules are already highly concentrated?
active transport
The Punnett square shows a cross between two flowers that exhibit a complete dominance inheritance pattern for petal color.
R is the allele for red petals, and r is the allele for blue petals. Which term describes the offspring of the cross represented by flower Z?
heterozygous dominant
heterozygous recessive
homozygous dominant
homozygous recessive
homozygous recessive
What process is labeled B and what is happening in that process?
Transcription, DNA --> RNA
Transcription, RNA --> Protein
Translation, DNA --> RNA
Translation, RNA --> Protein
In the past, scientists believed that the hippopotamus was most closely related to the wild pigs of Africa. Recent studies suggest that the closest living relatives of the hippopotamus are actually whales and porpoises. Which method of comparison provides enough evidence to justify the change in the classification of the hippopotamus?
Close observation of behaviors in the hippopotamus and pig populations revealed distinct differences.
Advancements in genetic engineering enabled scientists to compare all the groups of animals on a molecular level.
Embryological studies of all the groups showed distinct variations in the rate and order of embryo development.
Carbon dating of fossil remains revealed the hippopotamus existed millions of years before pigs.
Advancements in genetic engineering enabled scientists to compare all the groups of animals on a molecular level.
An unseasonably dry summer and fall followed by an early winter resulted in a shortage of producers in an ecosystem. As a result, the number of deer and wolves decreased.
Which reason explains why both populations experienced significant declines?
Organisms in food webs are interdependent, and a shortage of producers affects any food chain that relies on those plants.
Which balanced chemical equation represents aerobic cellular respiration?
Biologist T. H. Morgan conducted studies on the effect of light on the development of caterpillars of a butterfly species. He exposed the caterpillars to different colored lights and observed the wing colors after the caterpillars developed into butterflies. The table shows the results of his studies.
What can be concluded from the study?
The color of light influences the behavior of the caterpillars.
The color of light helps a caterpillar to develop into a butterfly.
The color of light causes a mutation in the gene responsible for wing color.
The color of light influences the expression of the gene that controls wing color
The color of light influences the expression of the gene that controls wing color
The diagram shows how cloned genes can be inserted into bacteria.
Why is the bacterial cell able to recognize the human gene and produce a human protein?
Bacteria and human cells contain the same number of chromosomes.
Bacteria and human cells contain DNA composed of the same four nucleotides.
Bacteria and human cells contain the same organelles.
Bacteria and human cells contain the same genes.
Bacteria and human cells contain DNA composed of the same four nucleotides.
Scientists use phylogenetic trees to compare organisms based on their evolutionary relationships and the time periods in which they existed. The three trees shown in the diagram illustrate the patterns of evolution in several organisms.
Which statement best explains the patterns represented in these phylogenetic trees?
Organisms at the end of each branch can be found in the present environment.
Closely related organisms always evolve at the same rate.
Organisms at the beginning of each tree exist longer because they are most adapted to their environment.
Throughout geologic history, organisms with traits ill-suited to the environment usually go extinct.
Throughout geologic history, organisms with traits ill-suited to the environment usually go extinct.