Chapter 2: Cell division Flashcards
What are haploids?
Cells such as sex cells that only contain 1 pair (23) chromosomes. The opposite are diploids
What are chromosomes?
The coils in our cells that DNA is stored in. Healthy humans usually have 46
What are allelles?
Different versions of the same gene. For example, the gene for eye colour has an allele for blue eye colour and an allele for brown eye colour. For any gene, a person may have the same two alleles, known as homozygous or two different ones, known as heterozygous.
What is a gene?
A section of a chromosome that contains coded instructions to create a protein
What is mitosis?
The process in which a cell divides, creating 2 identical daughter cells
How many stages are there in mitosis?
There are 6 stages in mitosis, excluding the interphase
What is interphase?
The step in which the cell spends 90% of its life, preparing for mitosis. The chromosomes make copies of themselves, meaning you get 92 chromosomes
What is the first step in mitosis?
The first step is the prophase, the step in which all the material inside the nucleus (chromatin) condenses. The mitotic spindle also forms, the spindle made of long proteins that controls where in the cell the DNA should go
What is the second step in mitosis?
The second step is prometaphase, the step in which the nuclear envelope breaks down
What is the third step in mitosis?
The third step is metaphase, the phase in which the chromosomes line up in the middle of the cell and become attached to the spindle fibers
What is the fourth step in mitosis?
The fourth stage is anaphase, the phase in which the chromosomes separate at the centromeres, and move to opposite sides of the cell
What is the fifth step in mitosis?
The fifth stage is telophase, the phase in which the spindle begins to break down, the cell begins to elongate, and nuclear membranes form around each set of chromosomes
What is the sixth step in mitosis?
The sixth stage is cytokinesis, the stage in which the cell splits into 2 daughter cells. The organelles later reform
What is a chromatid?
A copy of a chromosome
What are stem cells?
Stem cells are types of cells that can differentiate into any other type of cell