Cell Division Flashcards
Identify and describe the events of the cell cycle
Interphase
- > G1 (cell grows, synthesizes new proteins and organelles)
- > S (chromosomes are replicated, DNA synthesis takes place)
- > G2 (Prepares for mitosis, organelles and molecules required for cell division are produced)
M Phase
- >Mitosis (cell divides)
Identify the phases of mitosis in order
Interphase Prophase Metaphase Anaphase Telophase/Cytokinesis
Explain chromosome number through mitosis and meiosis
- > Cells are diploid throughout mitosis
- > Cells are diploid during the first half of meiosis, and haploid during the second half
Explain the product of mitosis
2 identical sister cells
Explain what cyclins are
They’re proteins that regulate the timing of the cell cycle
Relate cancer to mitosis
Cancer is a disorder in which some of the own body’s cells lose the ability to control growth during mitosis. Cancer cells don’t respond to signals that regulate the growth of most cells.
Describe the haploid phases of meiosis
Telophase 1/Cytokinesis - > nuclear membrane partially reforms NO SECOND INTERPHASE
Prophase 2 - > Nuclear envelope dissolves
Metaphase 2 - > Chromosomes line up in the middle of the cell
Anaphase 2 - > Chromosomes move to the poles
Telophase 2/Cytokinesis - > nuclear envelop forms, produces 4 genetically haploid cells different cells
Explain why it is necessary to reduce the number of chromosomes in gametes
Because 2 gametes must combine to create an embryo. if each gamete had the full number of chromosomes, the child would end up with double the number of chromosomes of the preceding generation, which can cause significant birth defects/ termination on the pregnancy.
Define diploid/haploid
- > Diploid cells contain two complete sets (2n) of chromosomes.
- > Haploid cells have half the number of chromosomes (n) as diploid - i.e. a haploid cell contains only one complete set of chromosomes.
Describe crossing over and its importance
It is the exchange of chromosome segments between chromatids in meiosis. Crossing over creates new combinations of genes in the gametes that are not found in either parent, contributing to genetic diversity.
List several differences between mitosis and meiosis
Mitosis
- > Involves one cell division
- > Produces two daughter cells
- > Produces diploid daughter cells
- > Daughter cells are genetically identical
Meiosis
- > Involves two successive cell divisions
- > Produces 4 four daughter cells
- > Daughter cells are genetically different
- > Creates germ cells (eggs and sperm)
Explain the difference in males and female gamete formation
Male gamete cells create four usable cells (sperm)
and females create one good (which is used for reproduction), and three smaller eggs which are broken down
Describe Interphase
cell grows and replicates its DNA and centrioles
Describe Prophase
The chromatin condenses into chromosomes. The centriole separates, and a spindle begins to form. The nuclear envelope breaks down. (spindle = protein thread)
Describe Metaphase
The chromosomes line up across the middle of the cel. Each chromosome is connected to a spindle fibre at its centromere
