Cell Cycle
This is the correct order of the phases of mitosis.
What is Prophase, Metaphase, Anaphase, Telophase?
A cross between two heterozygous tall pea plants (Tt × Tt) produces offspring in this phenotypic ratio
What is 3:1 (tall to short)?
This enzyme synthesizes an mRNA strand using a DNA template during transcription.
What is RNA polymerase?
Natural selection acts directly on this, not on genotype.
What is phenotype?
DNA is composed of repeating units called these.
What are nucleotides?
During this phase of the cell cycle, DNA replication occurs.
What is the S phase of interphase?
Red-green color blindness is X-linked recessive. A carrier female and a normal male produce sons with this probability of being color-blind.
What is 50%?
A three-nucleotide sequence on mRNA that specifies a particular amino acid is called this.
What is a codon?
The movement of alleles into or out of a population through migration is called this.
What is gene flow?
A population in Hardy-Weinberg equilibrium is characterized by this.
What is no evolution occurring / constant allele frequencies?
Meiosis produces this many cells with this ploidy.
What is four haploid cells?
This pattern of inheritance produces a blended phenotype in a heterozygous individual—like pink from red × white snapdragons.
What is incomplete dominance?
This is the region of DNA where RNA polymerase binds to begin transcription.
What is the promoter?
Genetic drift has the greatest effect on populations with this characteristic.
What is small population size?
In eukaryotes, before mRNA leaves the nucleus, this processing step removes non-coding sequences and joins the coding segments together
What is RNA splicing (removal of introns and joining of exons)?
These two events during meiosis generate genetic variation in gametes
What are crossing over and independent assortment?
A dihybrid cross between two doubly-heterozygous (AaBb) individuals produces offspring in this phenotypic ratio.
What is 9:3:3:1?
In the lac operon, the structural genes are transcribed at high levels under these conditions.
What is when lactose is present and glucose is absent?
When a small group colonizes an isolated island and starts a new population from a limited gene pool, this effect occurs.
What is the founder effect?
This type of homologous structure—like the forelimbs of whales, bats, and humans—provides evidence for common ancestry despite different functions.
What are homologous structures?
A species has 50 chromosomes. After meiosis, each gamete contains this many chromosomes.
What is 25?
Mendel's Law of Segregation states this about alleles and gamete formation.
What is that each organism carries two alleles for each gene, and they separate during gamete formation?
These changes can modify how genes are expressed without altering the DNA sequence, and can be reversible.
What are epigenetic changes?
When two populations become geographically isolated and eventually can no longer interbreed, this type of speciation has occurred.
What is allopatric speciation?
When a mutation disables a repressor in a repressible operon, the genes do this.
What is get transcribed continuously (constitutively expressed)?