Mitosis Flashcards
What are Acellular RNA and how do they store genetic information
No cellular structure
Viruses
Double or single stranded DNA or RNA
What are prokaryotes and where do they store genetic information.
Single cell organism that lacks a nucleus and other membrane bound organelles
E.e. Bacteria
Circular, single copy, naked double strand DNA
What are eukaryotes and where do they store their genetic information
Diverse domain of organisms whose cells have a nucleus
E.g. protest, fungi, plants, animals
Linear, more than or equal to a single copy, histone bound DNA
What is a karyotype and how is it taken
An ordered, visual representation of the chromosomes in a cell
Take blood sample, treat cells with mitogen, then colchicine
What human chromosomes exist in homologous pairs
Chromosomes 1-22
X and Y are sex chromosomes
What is a Locus
Place on chromosome where gene lives
What is a gene
The basic unit of heredity passed from parent to offspring
What is an allele
Alternating version/variants of a gene
What is a homozygote
2 same alleles at locus for a gene
What is a heterozygote
2 different alleles at locus for a gene
What do multicellular organisms depend on cell division for
Development from a fertilised cell
Growth to adult
Repair
What is interphase
The resting phase between successive mitotic divisions of a cell, or between the first and second division of meiosis
What is the mitotic phase
Phase of cell cycle where mitosis occurs
What are the 3 sub phases of interphase
G1 phase - Metabolic activity, growth
S phase - Metabolic activity, growth, DNA syntheses
G2 phase - Metabolic activity, growth, preparation for cell division
What are the subdivisions of the Mitotic phase
Mitosis - replicated chromosomes are separated into two new nuclei
Cytokinesis - separation into two new daughter cells
What is a duplicated chromosome
Two sister chromatids, which later seperate (during mitosis)
What is a centromere
Region of a chromosome to which the microtubules of the spindle attach, via the kinetochore, during cell devision
What is mitosis
Production of two genetically identical daughter cells
Consists of five phases:
Prophase
Prometophase
Metaphase
Anaphase
Telophase
What is prophase
First phase of mitosis
Complex of DNA and proteins (chromatin) condenses into chromosomes inside nucleus
Early mitotic spindle forms outside nucleus (forms between two asters/centrosome which move appart)
What is an aster
A cellular structure shaped like a star, consisting of a centrosome and its associated microtubules
What is prometaphase
Second phase
Nuclear envelope disintegrates
Centrosomes have moved to opposite poles of the cell
Kinetochore microtubules connect via kinetochore to centromere of sister chromatids
Non Kinetochore microtubules connect to Non Kinetochore microtubules of opposite pole
What is a kinetochore
A structure that connects microtubules to the sister chromatids
What is Metaphase
Third phase
All pairs of linked sister chromatids line up along metaphase plate (equator of cell)
Centromeres specifically line up on metaphase plate
Centrosomes are at opposite poles of the cell
What Is anaphase
Fourth phase
Kinetochore microtubules shrink, separating sister chromatids at centromere, pulled towards opposite poles
Non Kinetochore microtubules elongate and push the two poles apart
What is telophase and Cytokinesis
Fifth (last) phase
Reverse of prophase and prometaphase
Spindle disappears
Nuclear membranes start to form again
Chromosomes decondense into chromatin
Furrow forming in middle of cell, separating into two daughter cells
Cytoplasm splits compleately, forming 2 daughter cells (cytokinesis)
What chromosomes do the daughter cells of mitosis have
Each daughter cell has one copy of every chromosome
