IB 150 uiuc unit 2

interphase

the cell grows and makes copies of its dna

mitosis

cells separates its DNA and makes two sets, divides its cytoplasm, forms two new cells

G1

the cell grows larger, copies organelles, and makes the molecular building blocks it will need later on

S

cell synthesizes a complete copy of the DNA in its nucleus and duplicates it centrosome

G2

the cell grows more, makes protiens + organelles, reorganizes in preparation for mitosis

early prophase

chromosomes start condensing, nucleolos disappears mitotic spindle begins to form

late prophase/prometaphase

mitotic spindle begins organizing the chromosomes, chromosomes condense more, nuclear membrane goes away, mitotic spindle grows more + microtubules capture chromosomes

metaphase

spindle has captured all the chromosomes and lined up at the middle of the cell. two kinectochores of each chromosome are attached to microtubules from opposing spindle poles

anaphase

sister chromatids separate and are pulled to opposite ends of the cell protein holding sis. chromatids together disappears

telophase

mitotic spindle breaks into building blocks, two new nuclei form, nuclear membrane + nucleolous reappear, chromosomes decondense

cytokinesis

cleavage furow forms and cell separates into two

prophase 1

chromosomes begin to condense and pair up w/ homolog partner so that they line up along the entire length (this is when crossing over occurs)

metaphase 1

homologous pairs line up in the center of the cell. the orientation of the chromosomes is completely random

anaphase 1

homologs are pulled apart to opposite sides of the cell, but the sister chromatids remain together

telophase 1

chromosomes arrive at opposite poles of the cell and cytokinesis occurs. in some organisms nuclear membrane forms and the chromosomes decondense. (each chromosome has two non-identical sister chromatids)

prophase II

chromosomes condense, nuclear envelope breaks apart if needed, centrosomes move apart, spindle forms, spindle microtubules begin capturing chromosomes

metaphase II

chromosomes line up individually along the metaphase plate/center (sister chromatids are captured by microtubules from opposite spindle poles)

anaphase II

sister chromatids separate and are pulled to opposite poles of the cell

telophase II

nuclear membranes form around each set of chromosomes and the chromosomes decondense product = 4 haploid cells where each chromosome has just one chromatid

transcription initiation

rna polymerase binds to a sequence of DNA called the promoter, then it separates the DNA strands into the single strands needed for transcription

transcription elongation

one of the DNA strands acts as the template strand for RNA polymerase. the rna polymerase codes from 5’ to 3’ so it starts at the 3’ end of the template strand since DNA is antiparallel

transcription termination

sequences called terminators signal that the RNA transcript is complete. once the terminator is transcribed it causes the transcript to be released from the rna polymerase

translation initiation

ribosome assembles around mrna to be read and the trna carrying methionine arrives (it also has the anticodon that corresponds to the mrna codon)

translation elongation

the amino acid chain gets longer because the mrna is read one codon at a time and one amino acid is added for each codon

translation termination

when the stop codon enters the ribosome and triggers a series of events that separate the trna chain and allow it to drif out of the ribosome

homozygous

two fo the same copies of a particular allele

• two wild type

• two of the mutation

heterozygous

two different copies of a particular allele

• there are different types of dominant/recessive

• sometimes if an organism is heterozygous you don’t produce as much of.a trait/protein as a homozygous individual would

co-dominance

both alels are expressed and produce some sort of phenotypic effect (both are completely expressed eg. spots)

AND rule

probability that one independent event occurring AND another one

• multiply the individual probabilities together

OR rule

probability that offspring will receive a dominant from the mother OR a dominant from the father

• add the individual probabilities together

test-cross

cross a homozygous recessive individual with an individual that expresses the dominant phenotype to determine the genotype of the dominant phenotype individual

mendel’s first law of inheritance

allele pairs separate during the formation of gametes so that each gamete only receives one copy

mendels second law of inheritance

law of independent assortment