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CELL AND NUCLEAR DIVISION - Coggle Diagram
CELL AND NUCLEAR DIVISION
CELL CYCLE
REPRODUCTION IS THE FORMATION OF NEW CELLS FROM A PARENT CELL
INTERPHASE
S
DNA REPLICATION
G1
CELL GROWS AND PREPARES FOR DNA REPLICATION
G2
PREPARES FOR CELL DIVISION
ORGANELLES MUST BE DUPLICATED
TRANSCRIPTION AND TRANSLATION FOR SYNTHESIZING ENZYMES
M PHASE
MITOSIS
NUCLEAR DIVISION THAT RESULTS WITH 2 DAUGHTER CELLS WITH IDENTICAL CHROMOSOME NUMBER
MEOISIS
NUCLEAR DIVISION THAT RESULTS WITH 4 DAUGHTER CELLS AND HALF THE CHROMOSOME NUMBER
CYTOKINESIS
THE CYTOPLASM DIVIDES TO PRODUCE NEW CELLS
CYTOKINESIS
ANIMAL CELLS
ACTIN
AND
MYOSIN
FILAMENTS FORM A
CONCENTRIC RING
THE CELL BECOMES COMPLETELY PINCHED OFF AND THE 2 CELLS ARE FORMED
PLANT CELLS
VESICLES
FORM IN A ROW AT THE CENTRE OF THE CELL
THE VESICLES FUSE TOGETHER, DIVIDING THE CELL IN 2
UNEQUAL CYTOKINESIS
USUALLY CYTOKINESIS IS EQUAL BETWEEN DAUGHTER CELLS
ALL CELLS MUST RECEIVE AT LEAST 1 MITOCHONDRION AND ANY OTHER ORGANELLE THAT CAN BE MADE BY DIVIDING A PRE-EXISTING STRUCTURE
BUDDING
OCCURS IN
YEAST
THE DIVISION OF CYTOPLASM IS ASYMMETRICAL
THE DAUGHTER CELL RECEIVES ONLY A FRACTION OF THE CYTOPLASM FROM THE PARENT CELL
OOGENESIS
EGG CELLS ARE PRODUCED FOLLOWING MEIOTIC DIVISION
THE CYTOPLASM AND ORGANELLES ARE RETAINED BY A SINGLE CELL
THE REST FORM A SMALL
POLAR BODY
THAT WILL DISINTEGRATE
ROLE OF CEL DIVISION
NUCLEAR DIVISION IS NEEDED BEFORE CELL DIVISION TO AVOID THE PRODUCTION OF ANUCLEATE CELLS
MITOSIS MAINTAINS THE CHROMOSOME NUMBER AND GENOME OF CELLS
MEIOSIS HALVES THE CHROMOSOME NUMBER AND GENERATES GENETIC DIVERSITY
DNA REPLICATION
AFTER DNA REPLICATION, EACH CHROMOSOME IS COMPOSED OF 2 ELONGATED DNA MOLECULES
THESE 2 STRUCTURES ARE CALLED
CHROMATIDS
AND THEY ARE CONNECTED BY THE
CENTROMERE
THEY SEPARATE ONLY DURING ANAPHASE
THEY ARE GENETICALLY IDENTICAL SISTER CHROMATIDS
THEY ARE HELD TOGETHER BY PROTEIN COMPLEXES, CALLED
COHESIONS
CONDENSATION
DNA IS ASSOCIATED WITH
HISTONE
PROTEINS BY SUPERCOILING TO FORM CHROMATIN
ACTIVE
GENES ARE LOOSELY PACKED AS
EUCHROMATIN
INACTIVE
GENES ARE MORE TIGHTLY PACKAGED AS
HETEROCHROMATIN
CHROMOSOME MOVEMENT
MOVEMENT OF CHROMOSOMES IS CONTROLLED BY
KINETOCHORES
AND
MICROTUBULES SPINDLES
KINETOCHORES ARE PROTEIN COMPLEXES THAT ASSOCIATE WITH EACH SISTER CHROMATID AT THE CENTROMERE
THE KINETOCHORE LINK THE CHROMATIDS TO MICROTUBULE FILAMENTS
MICROTUBULE FILAMENTS
PULL THE SISTER CHROMATIDS AWAY
MOTOR PROTEINS
THESE MOVE ALONG THE MICROTUBULE FILAMENTS AND REGULATE THE LENGTHENING OR SHORTENING OF THE SPINDLES
DYNEINS
MOVE AWAY FROM THE KINETOCHORE REGION
KINESINS
MOVE TOWARDS THE KINETOCHORE REGION
MITOSIS
METAPHASE
KINETOCHORES
ATTACH TO THE CENTROMERE AND CONNECT IT TO THE MICROTUBULE SPINDLE FIBRES
CHROMOSOMES MOVE AND
ALIGN
AT THE CENTRE OF THE CELL
ANAPHASE
COHESIONS BETWEEN CHROMATIDS ARE REMOVED
THE CHROMATIDS ARE
SEPARATED
TOWARDS THE OPPOSITE POLES OF THE CELL
PROPHASE
DNA SUPERCOILS AND CHROMOSOMES
CONDENSE
CHROMOSOMES ARE COMPOSED OF SISTER CHROMATIDS
CENTROSOMES
MOVE TO OPPOSITE POLES OF THE CELL AND PRODUCE
MICROTUBULE SPINDLE FIBRES
THE NUCLEAR MEMBRANE BREAKS DOWN
TELOPHASE
SPINDLE FIBRES DISSOLVE
CHROMOSOMES
DECONDENSE
NUCLEAR MEMBRANE REFORMS
IT IS PROCEEDED BY
INTERPHASE
WHICH IS WHEN DNA IS REPLICATED
MITOTIC INDEX
CELLS IN MITOSIS / TOTAL NUMBER OF CELLS
MEIOSIS
THE CELL IS DIPLOID (46 CHROMOSOMES)
MEIOSIS 1 IS THE REDUCTIONAL DIVISION WHERE 2 HAPLOID CELLS ARE PRODUCED WITH 23 CHROMOSOMES
MEIOSIS 1
THIS IS THE REDUCTION DIVISION IN WHICH HOMOLOGOUS CHROMOSOMES ARE SEPARATED
IN PROPHASE 1, THE HOMOLOGOUS CHROMOSOMES BECOME CONNECTED AT POINTS CALLED
CHIASMA
TO FORM
BIVALENTS
THE HOMOLOGOUS CHROMOSOMES WILL MOVE TO OPPOSITE POLES OF THE CELL
MEIOSIS 2
THIS SEPARATES THE SISTER CHROMATIDS
ALL CELLS WILL BE HALPOID
CROSSING OVER
HOMOLOGOUS CHROMOSOMES BECOME CONNECTED VIA
SYNAPSIS
IN SYNAPSIS, NON-SISTER CHROMATIDS MAY RECOMBINE WITH THEIR HOMOLOGOUS PARTNER
THESE POINTS OF EXCHANGE ARE CALLED
CHIASMATA
THESE
RECOMBINANTS
CHROMOSOMES ARE GENETICALLY DIFFERENT FROM THE ORIGINAL CHROMOSOMES
RANDOM ASSORTMENT
WHEN HOMOLOGOUS LINE UP, THEIR ORIENTATION TOWARDS THE OPPOSING POLES IS RANDOM
THIS MAKES A LARGE NUMBER OF CHROMOSOME COMBINATIONS THAT CAN OCCUR IN GAMETE
NON-DISJUNCTION
NUCLEAR DIVISION ERROR WHERE CHROMOSOMES FAIL TO SEPARATE CORRECTLY DURING ANAPHASE
THE GAMETE WILL EITHER HAVE AN EXTRA OR A MISSING COPY OF A CHROMOSOME
IT CAN HAPPEN EITHER IN
ANAPHASE 1
(AFFECTING ALL DAUGHTER CELLS) OR
2
(AFFECTING 2 DAUGHTER CELLS)
THE PRESENCE OF AN ABNORMAL CHROMOSOME NUMBER IS KNOWN AS
ANEUPLOIDY
DOWN SYNDROME
WHEN THE ZYGOTE HAD 3 COPIES OF CHROMOSOME 21
CELL PROLIFERATION
CELLS GROW AND DIVIDE TO PRODUCE DAUGHTER CELLS IN MULTICELLULAR ORGANISMS
GROWTH
GROWTH OF AN ORGANISM IS MEDIATED BY THE PROLIFERATION OF STEM CELLS
PLANTS RETAIN PLURIPOTENT CELLS IN
MERISTEMS
GROWTH CAN ALSO BE SEEN IN EARLY-STAGE ANIMAL
EMBRYOS
REPAIR
CELL PROLIFERATION CAN ALSO BE USED FOR REPLACING CELLS TO REGENERATE
TISSUES
THAT HAVE BEEN DAMAGED
FOR EXAMPLE, SKIN HEALING
CELL PROLIFERATION IS ACHIEVED THROUGH THE CELL CYCLE
CONTROL OF THE CELL CYCLE
CHECKPOINTS
G2 CHECKPOINT
DETERMINES THE STATE OF A PRE-DIVIDED CELL
METAPHASE CHECKPOINT
ENSURES PROPER SPINDLE ASSEMBLY
G1 CHECKPOINT
CONFIRMS APPROPRIATE GROWTH CONDITION
CYCLINS
CYCLINS ACTIVATE
CYCLIN DEPENDENT KINASES
, WHICH CONTROL THE CELL CYCLE
CYCLINS AND CDKS WILL FORM A
PROTEIN COMPLEX
THAT WILL BIND AND PHOSPHORYLATE A PROTEIN
THE PROTEIN WILL THEN TRIGGER AN EVENT WITHIN THE CELL
CONCENTRATIONS OF DIFFERENT CYCLINS WILL INCREASE AND DECREASE DURING THE CELL CYCLE
A
THRESHOLD
LEVEL OF A SPECIFIC CYCLIN IS REQUIRED TO PASS EACH CHECKPOINT
MUTATIONS
PROTO-ONCOGENES
CODE FOR PROTEINS THAT
STIMULATE
THE CELL CYCLE AND CELL GROWTH
WHEN THESE GENES ARE MUTATED IT BECOMES AN
ONCOGENE
(CANCER-CAUSING GENE)
TUMOR SUPPRESSOR GENES
CODE FOR PROTEINS THAT
REPRESS
CELL CYCLE
TUMORS
TUMOR CELLS MAY REMAIN IN THEIR ORIGINAL LOCATION (
BENIGN
),THESE DO NOT CAUSE CANCER
OR SPREAD AND INVADE NEIGHBOURING TISSUE (
MALIGNANT
), THESE CAUSE CANCER
METASTASIS
IS THE SPREAD OF CANCER FROM ONE LOCATION (
PRIMARY TUMOR
) TO ANOTHER (
SECONDARY TUMOR
)