EOY B2 Flashcards
How many sections is DNA divided into? What are they called?
46 chromosomes
How many different types of chromosomes are there?
23
What is the 23rd pair of chromosomes?
Sex chromosomes
What are the women and men sex chromosomes?
Women have xx
Men have xy
When do chromosomes look like x’s?
Only before cell division, before undergoing Meiosis or Mitosis
What is a gene?
A section of DNA that codes for a protein. It is like a small section of a chromosome
What is a genome?
The entire set of genetic material in an organism
What can sequencing a genome do?
Help understand inherited disorders and can help the person with it understand what to do to prevent risks and what medication they should take
What is a karyotype?
A picture of all of a person’s chromosomes.
What are homologous chromosomes?
They are from different parents but contain the same types of genes in the same location.
What are autosomal chromosomes?
1-22 They don’t directly determine sex
What is monosomy?
Having one chromosome where you should have a homologous pair
What is Turner’s syndrome?
Where someone has only a single x sex chromosome
What is trisomy 21?
Down’s syndrome- 3 homologous chromosomes in 21.
How many main stages of the cell cycle are there?
3- Growth, DNA replication, Mitosis (Cytokinesis)
What happens in step one of three of the cell cycle?
Cell grows in size
Increases number of sub cellular structures (mitochondria, ribosomes)
DNA replicated to form two copies of each chromosome ready for cell division
When no dividing, DNA is in long strings, when cell prepares for division, DNA condenses into chromosomes.
Then it duplicates each of the 46 chromosomes and the duplicate stays attached to the original chromosome so together they form an x shape
What happens in step two of three of the cell cycle?
Mitosis
When the cell is ready to divide, all the chromosomes line up in the centre of the cell.
Fibres come from each side of the cell and attach to their respective half of each chromosome.
These fibres pull the arms of the chromosome to each side of the cell which are called poles.
Keep Going!!!
🙂↕️🩵🧋
What happens in step three of three?
Cytokinesis-
Cell membrane and cytoplasm pull apart making 2 daughter cells. Both have the same genetic material (so are identical).
What is the difference between the cell cycle and mitosis?
The cell cycle refers to the cell’s lifecycle or the period of cellular growth and DNA replication. Mitosis represents the final step in the cell cycle. Mitosis results in the production of two identical daughter cells.
What is the interphase?
This is when nothing significant happens to the cell, most cells spend more time here.
This is except cancer cells
What is the P in PMAT?
Prophase- Nucleus is still there, chromosomes are condensing (they are visible)
What is M in PMAT?
Metaphase- (middle)
Chromosomes line up middle of the cell, nucleus disassembled
What is A in PMAT?
Anaphase- (away)
Chromosomes go to poles via ‘spindles’