Cell Division Flashcards
Cell continuity
All cells develop from pre existing cells
Chromosomes in the form of long,thin threads
Chromatin
Number of chromosomes in each body cell of a human.
46
Chromosomes: definition
Thread like structures that contain DNA and protein found in the nucleus of the cell.
Gene : definition
A section of DNA that are our units of inheritance
Haploid cell : definition
Cell which contains only one of each type of chromosome
Haploid cell : n = ?
23
Diploid cell : definition
A cell which contains 2 sets of chromosomes.
Diploid cell : 2n=?
46
Homologous pair (diploid cell)
One set of chromosomes comes from the father, the other from the mother
The cell cycle
Describes the life cycle of the cell
Interphase
The phase in the cell cycle when the cell is not dividing.
How much of the cell cycle does interphase account for ?
90%
How do chromosomes appear during interphase ?
Chromatin
What does the cell do during interphase?
Very active. Produces new organelles. Forms chemicals needed for growth (proteins and enzymes)
Mitosis: definition
A form of nuclear division in which one nucleus divides to form 2 identical nuclei.
Type of cell formed by mitosis
Daughter cells
Stage 1?
Prophase
•nucleor membrane begins to breakdown
•spindle fibres form
•chromatin become chromosomes
Stage 2?
Metaphase:
•chromosomes line up at equator
•spindle fibres connect to centromere
Stage 3?
Anaphase:
•spindle fibres contract
•1 chromosome from each pair pulled to each end of cell (identical)
Stage 4?
Telophase:
•nucleor membrane re-forms
•chromosomes become chromatin and 2 identical nuclei form
