Cell Cycle Flashcards
(38 cards)
Cycle of Cell Division
Interphase - grows, checkpoint, replication, preparation, checkpoint.
Mitosis - prophase, metaphase and checkpoint, anaphase, telophase.
Cytokinesis
Cell Theory
All living things are made from cells.
The cell is the smallest living thing that can perform all the functions of life.
All cells must come from pre-existing cells (cell division).
Why do cells need to divide?
To make your body grow.
To maintain and repair damage
to reproduce
If a cell gets too big, it wont be able to get enough nutrients through our body.
Centrioles
All animal cells have 2 small organelles known as centrioles. Centrioles help cells to divide and are typically located near the nucleus. Made of 9 bundles of microtubes, arranged in a ring. Centrioles separate and grip onto each side of a cell and pull the chromosomes apart using spindle fibres.
Spindle Fibres
Spindle fibres form a protien structure that divides the genetic material in a cell. The spindle is necessary to equally divide the chromosomes in a parental cell into 2 daughter cells during both types of nuclear division; mitosis and meiosis. During mitosis, the spindle fibres are known as mitotic sipindle.
Sister Chromatids & Chromosomes
When a single chromosome has been replicated/copied, each copy is called a sister chromatid. When you see an “X” representing genetic material in an illistration, you are seeing 2 sister chromatids held together by a special part of the chromosome called the centromere. When cell division occurs, it separates at the middle and one part goes into each divided cell.
Cleavage Furrow
The band of microfilaments during cytokinesis in cell division that splits the two daughter cell’s membranes in half.
Cell division definition
The process by which one cell divides into two.
What is a parent cell?
A parent cell is the original, undivided cell.
What is a daughter cell?
Daughter cells refers to the two new cells after cell division occurs.
Daughter cells are the exact same as parent cells because…
The parent cell duplicates the DNA before it begins mitosis so that when it divides, the two daughter cells each recieve the full set of DNA.
How do unicellular organisms divide?
Through a process called asexual reproduction.
What does chromatin do to create a more effective division?
It duplicates itself and coils up into a chromosome.
Somatic definition
Body.
Interphase
A period of cell growth.
The DNA duplicates itself.
Centriole pair replicates.
Cell grows, carries out its normal cell activities, and replicates all other organelles.
Spends most of its life cycle here.
Mitosis
Occurs in all somatic cells.
Occurs so that each new daughter cell has a nucleus, complete with a set of chromosomes.
There are four stages of mitosis (PMAT)
Prophase
Centriole pairs begin to migrate to opposite poles.
Chromosomes coil up.
Duplicated chromosomes thicken and condense.
Nuclear envelope starts to disappear.
Spindle fibres begin to form.
Nucleolus starts to disappear.
Metaphase (middle)
Chromosomes line up in the middle of the cell (equalortial plate).
Spindle fibres connect to each side of the chromosomes.
Centriole pairs fully migrated to the opposite poles.
Nuclear envelopes fully disappear.
Spindle fibres fully formed.
Anaphase
Chromosome copies divide
Spindle fibres pull sister chromatids apart at the centromere and pull them to opposite poles.
Cell elongates.
Telophase
Chromsomes uncoil and decondense.
Nuclear envelopes form.
2 new nuclei are formed.
Spindle fibres disappear.
Begins cytokinesis by forming a cleabage furrow.
Nucleoli begin to reform within nuclei.
Cytokinesis
The division of the rest of the cell (cytoplasm & organelles) after the nucleus divides.
In animal cells, the cytoplasm pinches in to form circles.
In plant cells a cell plate forms (square cells).
The new cells then return to interphase and the cycle repeats.
Meiosis
Meiosis has two of each stage because it divides into four cells, eahc with half of the information instead of two with all of it.
There’s interphase G1, interphase S, Prophase 1, Metaphase 1, Anaphase 1, Telophase 1, Prophase 2, Metaphase 2, Anaphase 2, and Telophase 2.
Each faze is exactly the same as mitosis except each one happens twice with very minor adjustments depending on previous stages.
Diploid definition
A set of two.
Haploid definition
single chromatid