Cell Division Flashcards
Why do cells reproduce instead of just grow larger?
If they grow beyond a certain size, they will not be able to carry out any metabolic functions.
Name 3 reasons why cells divide.
Growth/differentiation, maintenance, repair
What is a somatic cell? A parent cell? Daughter cell?
A somatic cell is a cell that is part of the body. A parent cell is the original cell. A daughter cell is a newly formed cell.
What is the cell cycle measured from?
Measured from one cell division to the next.
What does it mean for genetic material to be central?
It must be appropriately divided between cells.
What is the constricted region in the center of a chromosome called?
A centromere.
In eukaryotic cells, where is DNA found?
In a eukaryotic cell, DNA is in the membrane bound nucleus.
What state is DNA in when the cell is not dividing?
It is unwound and in the chromatin form.
What is the difference between chromatin and chromosome?
Chromatin is unwound DNA and chromosome is wounded DNA.
What type of cells contain homologous pairs of chromosomes?
Somatic Cells
How many chromosomes do human cells have?
46
How many pairs of DNA are non-sex homologous pairs?
22
What are some similarities in homologous pairs? (4)
Length, gene location, centromere location, and responsible for the same type of characteristics
What are non sex chromosomes called?
Autosomes
During replication, a chromosome will form that X shape. What is each half of the X called?
Sister chromatids
Are homologous chromosomes identical to each other?
No, they share similar characteristics though but carry different alleles of the same gene.
What are genes in regards to DNA?
They are areas of DNA that contain specific information.
What are alleles?
Slightly different versions of the same gene on homologous chromosomes.
What is a location of the gene on a DNA called?
Locus
What is a diploid cell? Haploid? Polyploid?
Diploid cells have two sets of homologous chromosomes. Haploids have one set and polyploids have more than 2 sets.
What type of cell are used for karyotypes?
Stained chromosomes from a dividing cell.
What does a karyotype check for?
Differences/abnormalities which could infer a genetic disorder.
What are the three phases of the interphase stage? What is another name of the interphase stage?
G1 phase, S phase, G2 phase. Another name for the interphase stage is growth stage.
What happens in the G1, S and G2 phase? Describe the state the DNA is in for each.
G1=cell growth (organelle replication) The DNA is 46 single strands of chromatin.
S/Syntehsis phase = DNA is replicated The DNA is 46 double strands of chromatin.
G2= second growth stage which rebuilds energy reserves and prepares the cell for division. Cell manufactures proteins and materials for cell division. DNA is in the chromosome state.
What are the two stages of the cell cycle?
Interphase stage and division stage.
During what stage of the cell cycle does a chromosome form?
S phase
What happens during mitosis? Cytokinesis?
Mitosis is the division of genetic material and the nucleus. Cytokinesis is the division of cytoplasm and organelles.
At what stage does a regular cell spend most of its life?
The growth stage/interphase.
What are the two main processes in the cell division stage?
Mitosis and cytokinesis.
What process during the cell cycle officially splits the parent and daughter cells?
Cytokinesis
What do cyclins bind to?
Cyclin dependent kinases which are enzymes.
What are cyclins?
A group of proteins that ensure tasks are performed at the correct time.
How do kinases activate the cyclins?
They phosphorylate them.
What are the four cyclin types and what do part of the cycle do they control?
Cyclin D- G0 to G1 and G1 to S
Cyclin E- Prepares DNA for replication in S
Cyclin A- Activates DNA replication in S
Cyclin B- Prepares cell for mitosis in G2 (like promotes mitotic spindle)
When is the next cycle triggered in accordance to the levels of cyclin?
When cyclin concentrations reach the threshold level.
What is the acronym for the 4 cyclin types?
DEAB
