unit 5 and 6 salo - bio

interphase

the stage in which the cell grows, carries out cellular functions, and replicates in DNA in preparation for the next stage of the cycle

mitosis

the stage of the cell cycle during which the cell's nucleus and nuclear material divide

cytokenesis

the method by which a cell's cytoplasm divides, creating a new cell

prophase

chromatin becomes individual chromosomes, spindle starts to form

metaphase

spindle fibers attach to the centrosome, sister chromatids line up in the middle of the cell, ensures cells have accurate copies of the chromosomes

anaphase

sister chromatids are pulled apart, spindle fibers shorten and mover chromosomes to the poles, sister chromatids separate into identical single chromosomes

chromosomes

structures that contain genetic material (DNA)

chromatin

relaxed form of dna (in the nucleus)

sister chromatid

structures that contain identical copies of DNA

centromere

where microtubules of spindle fibers attach, middle of sister chromatids

apoptosis

programed cell death (occurs in cells damaged beyond repair or to prevent cancerous growth)

cleavage furrow

when the cell membrane is drawn inward (occurs in animal cell cytokinesis)

cell plate

separates the daughter cells in plant cell cytokinesis

cancer

uncontrolled growth and division of cells

tumor

mass of cancer cells

carcinogen

substances known to cause cancer

mutagen

substance that causes mutation (example: radiation)

DNA helicase

enzyme that unzips the double helix

RNA primase

enzyme that adds an RNA primer to indicate the start of a new DNA strand

DNA polymerase

enzyme that joins the sugar phosphate backbone together to produce a new strand of DNA

DNA ligase

connects DNA fragments on the lagging strand (Okazaki fragments) together

deoxyribose

five-carbon sugar component of DNA

Purine

Adenine and Guanine (base pairs)

Pyrimidine

Cytosine and Thymine (base pairs)

DNA replication

occurs during the S phase of interphase, two strands unzip, bases are added, results in two identical DNA molecules

ribose

sugar in RNA (5 carbon)

mRNA (messenger ribose)

has instructions for making proteins from DNA

rRNA (ribosomal RNA)

part of a ribosome

Transfer RNA (tRNA)

transfers amino acids to the ribosome to make a protein during translation

Transcription

producing mRNA from a DNA segment

RNA polymerase

binds to DNA and separates the DNA strands

Codon

the three-base code in DNA or mRNA that codes for an amino acid

Translation

Process by which mRNA is decoded and a protein is produced

Anticodon

group of three bases on a tRNA molecule that are complementary to an mRNA codon

Nondisjunction

cell division during which chromosomes fail to separate properly during meiosis

Mutation

a permanent change that occurs in a cell's DNA

Gene mutation

produce changes in a single gene

Chromosomal mutation

produce changes in whole chromosomes

Substitution mutation

one base is changed to a different base

Missense substitution

an incorrect amino acid is coded for

Nonsense substitution

a stop codon is coded for instead of an amino acid

Silent substitution

the mutation still codes for the correct amino acid

Frameshift mutation

Insertions: one base is inserted into the DNA sequence - Deletions: one base is removed from the DNA sequence

Mutagens

A chemical or physical agent that interacts with DNA and causes a mutation.

Deletion

involves the loss of all or part of the chromosome

Duplication

produces an extra copy of all or part of a chromosome

Inversion

reverses the direction of parts of a chromosome

Translocation

part of one chromosome breaks off and attaches to another