Biology 7 Flashcards
(28 cards)
Transcription
Build mRNA from DNA
Translation
Converts mRNA message into a polypeptide/protein
Point Mutation
When one base pair is altered but reading frame of codons is not affected. Silent, substitution, premature stop
Frameshift mutation
Changes the reading frame of codes. Insertion and deletion
Silent mutation
Base pair is substituted but the change codes the same
Substitution/ Missense
A base pair is substituted and the new codon codes for a different amino acid. Most likely will not work
Premature stop/ Nonsense
When a substitution results in the formation of a STOP codon before all of the codons have been read and translated by the ribosome.
Insertion
One or more base pairs is added to a sequence (one dangling base)
Deletion
One or more base pairs is lost from a sequence (Two left over)
4 main stages to the cell cycle
G1, S, G2, M
G1
cells grow- replicate organelles
S
Synthesis DNA is copied
G2
More growth
M
2 steps- Mitosis and cytokinesis
Mitosis
division of cell nucleus
Cytokinesis
division of cytoplam
Cells divide at different rates
Prokaryotes divde faster than eukaryotes
Rate of division depends on bodies need for those cells
Embryos (fastest), Children (fast), Adults (slowest)
Condenses/ coils at the start of mitosis
chromosomes
Body cells have _ chromosomes each
46
During mitosis DNA must tightly coil up into
Chromosomes. If it remained loose it could become tangled
Chromatin
Loosley coiled DNA
2 identical chromatids
sister chromatids
Interphase
prepares cell to divide all genetic material
