2.1 Cell Division Review Flashcards
(33 cards)
What is Genetics?
It is the study of how genes pass from one generation to the next.
What is Cell Theory? (3)
- Cells are the smallest unit of life
- All living things are made of 1+ cells
- All cells are made from other cells
What are the main reasons for Cell Division? (3)
- Growth
- Replace old cells
- Repair
What happens when the cell gets too big?
- Difficulty doing normal cell functions (taking in nutrients/removing waste)
- Cytoplasm can’t exchange nor transport gases, nutrients
- Cell divides
Why do some types of cells constantly replace? Example?
Because they are in high motion areas.
Ex: skin, gut lining
Do some cells lose ability to divide at an early age? Example?
Yes
Ex: muscle cells, nerve cells
What are the Stages of the Cell Cycle? (3)
- Interphase
- Mitosis
- Cytokinesis
What happens in Interphase?
- Normal cell activities
- Growth of cell
- DNA is copied
What happens in Mitosis?
- Cell undergoes the process of nuclear division
What happens in Cytokinesis?
When?
- Cytoplasm splits equally into 2 new identical cells. (The cell membrane pinches along the equator of the cell)
- Near the END of mitosis
What are the phases of Interphase? (3)
- G1 (growth 1) Phase:
Major Growth, production of required molecules - S (synthesis) Phase:
DNA is copied - G2 (growth 2) Phase:
more growth, production of molecules for cell division
What are Somatic cells?
All cells of the body except reproductive ones.
How many chromosomes do somatic cells in humans have?
46 chromosomes
How many chromosomes do reproductive cells have?
23 chromosomes
Simply describe what happens in Mitosis (2)
- Replicated genetic material(DNA) separates
- Parent cell prepares to split into 2 daughter cells
What is Chromatid?
Chromatid: When genetic material duplicates, it creates 2 identical sister Chromatin. If they are held together to create a chromosome, each arm is chromatid.
What is Chromatin?
The strand of DNA itself, that creates the chromosome
What is a Chromosome?
It is tightly wrapped DNA
What occurs in Prophase? (4)
- Nuclear membrane + nucleolus disappears
- Cell’s chromatin condenses into chromosomes
- The Chromosome “arms” (chromatid) are held tog by a centromere
- CENTROSOMES project spindle fibers and MOVE TO OPPOSITE POLES.
What is a centrosome?
The organelle that creates spindle fibres and separates the sister chromatids/splits the chromosome.
What is a centromere?
It is what holds 2 sister chromatids together.
What happens in Metaphase?
- Spindle fibers guide the chromosomes to the equator(central line) of the cell.
- They then attach to the centromere of each chromosome.
What happens in Anaphase? (3)
- Each centromere splits apart and separates the sister chromatids
- Spindle fibres pull chromosomes to opposite poles of the cell
- Each sister chromatid is now its own chromosome
What occurs in telophase?
- Chromosomes reach the OPPOSITE POLES of the cell
- Chromosomes UNWIND into chromatin
- Spindle fibers BREAK DOWN
- Nuclear membrane starts to REFORM around the new chromosomes
