DNA Replication
What is S-phase?
The phase of the cell cycle (specifically interphase) during which DNA replication occurs.
What are gametes?
The type of cells (biological term) produced by meiosis.
What is a ribosome?
The organelle in the cell where translation (building the protein) occurs.
What is a mutation?
A change in the DNA sequence of an organism.
What is a transgenic organism?
An organism that contains DNA from another species.
What is helicase?
This enzyme is responsible for "unzipping" the DNA double helix by breaking hydrogen bonds.
What is crossing over?
This process during Prophase I involves the exchange of genetic material between homologous chromosomes.
What is transcription?
The process of copying a DNA sequence into a strand of mRNA.
What is a point mutation?
A mutation that involves the replacement of a single nucleotide with another.
What is PCR (Polymerase Chain Reaction)?
The technique used to make many copies of a specific DNA segment quickly.
What is DNA polymerase?
The primary enzyme that adds complementary nucleotides to the growing DNA strand.
What is 20? (Meiosis produces haploid cells)
If a parent cell has 40 chromosomes, this is the number of chromosomes each daughter cell will have after meiosis.
What is a codon?
A three-nucleotide sequence on mRNA that codes for a specific amino acid.
What is a frameshift mutation?
This type of mutation occurs when a nucleotide is added or deleted, shifting the entire "reading frame."
What are restriction enzymes?
"Biological scissors" used to cut DNA at specific sequences.
What is semi-conservative?
Term describing replication because each new DNA molecule consists of one original strand and one new strand.
What is a tetrad?
The structure formed when two homologous chromosomes (four chromatids) pair up during meiosis.
What is tRNA (Transfer RNA)?
This type of RNA molecule brings amino acids to the ribosome.
What is an inversion?
A chromosomal mutation where a segment of DNA is reversed or "flipped" end-to-end.
What is a plasmid?
The name for a small, circular DNA molecule found in bacteria that is often used as a "vector" to carry foreign genes into a host cell.
What are Okazaki fragments?
Small segments of DNA synthesized on the lagging strand that are later joined together.
What is nondisjunction?
The failure of chromosomes to separate properly during meiosis, which can lead to disorders like Down Syndrome.
What is an anticodon?
The three-base sequence on tRNA that is complementary to an mRNA codon.
What is a point mutation?
The specific type of mutation that causes Sickle Cell Anemia, where a single adenine is replaced by a thymine.
What are sticky ends?
The name for the uneven, "overhanging" ends of DNA left by certain restriction enzymes, which allow different DNA fragments to easily bond together.