Mitosis
This stage of interphase is when the cell replicates its DNA.
S phase
These are the cells in an organism that undergo meiosis to form gametes.
Germ Cells
This term describes an organism that has two identical recessive alleles for a specific trait.
Homozygous Recessive
This enzyme unwinds the DNA double helix at the replication fork, separating the two strands so they can be copied during DNA replication.
Helicase
This specific codon signals the start of translation and codes for the amino acid methionine.
AUG
During this stage of mitosis, chromosomes align along the cell’s equator.
Metaphase
This term describes a condition in which a cell has an abnormal number of chromosomes, often caused by nondisjunction.
Aneuploidy
Mendel’s law stating that each gamete receives only one allele of a gene from each parent during gamete formation.
Law of Segregation
This enzyme synthesizes the leading strand during eukaryotic DNA replication.
DNA polymerase ε
This molecular machine reads mRNA sequences and links amino acids together in the correct order to build a protein.
Ribosome
This type of chromatin is loosely packed and actively transcribed.
Euchromatin
After meiosis II, this is the total number of genetically unique haploid cells produced from one original diploid cell.
Four
Mendel’s law stating that alleles of different genes are distributed independently of each other during gamete formation.
Law of Independent Assortment
These specific sites on DNA, often rich in A-T base pairs, mark where replication begins and are recognized by the origin recognition complex.
Origins of Replication
During elongation, this step moves the ribosome along the mRNA so that a new codon enters the A site while the empty tRNA exits from the E site.
Translocation
These repeating units of DNA are wrapped around histone proteins to form chromatin.
Nucleosomes
This protein protects cohesin in meiosis I, keeping sister chromatids together, but is removed in meiosis II so they can separate.
Shugoshin
This type of inheritance occurs when both alleles for a trait are fully expressed in a heterozygous individual, as seen in blood type AB, where both A and B antigens are present.
Codominance
These short DNA segments are synthesized discontinuously on the lagging strand during DNA replication and are later joined together by DNA ligase.
Okazaki Fragments
This type of transcription termination in bacteria occurs when a hairpin loop forms in the RNA followed by a stretch of uracils, causing RNA polymerase to detach.
Rho-Independent
This checkpoint ensures all chromosomes are properly attached to spindle fibers before anaphase begins.
Metaphase Checkpoint of Spindle Assembly Checkpoint
During this substage of prophase I in meiosis, homologous chromosomes are fully paired and crossing over occurs.
Pachytene Stage
In a cross between two heterozygous pea plants for two traits (GgYy × GgYy), the F₂ offspring showed this consistent ratio of phenotypes.
This complex forms during S phase, activating the helicase at replication origins and recruiting DNA polymerases to begin synthesizing new DNA strands.
Pre-Initiation Complex
This protein recognizes and binds to a specific DNA sequence in the promoter region to help position RNA polymerase II correctly during transcription initiation.
TATA-Binding Protein (TBP)