Chapter 14 - New Body Cells Flashcards
What is the average life span of cells that make up your intestinal lining, the inside of your check and the alveolus of your lungs?
Intestinal lining - 1.3 days
Inside of your cheek - 10 days
Alveolus - 21 days
What are the four phases of the cell cycle?
G1 phase - first growth phase. The cell produces new proteins, grows and carries out it’s normal tasks. This phase ends with the DNA begins to duplicate
S phase - synthesis phase. The DNA molecules form exact duplicates of themselves.
G2 phase -second growth phase. The cell prepares for division.
M phase - mitotic phase. The cell divides into two daughter cells.
Some cells continue the cell cycle where as others leave and stop dividing for various amounts of time. They are are in the G0 phase.
What are the six phases of mitosis?
IPMATC
Interphase - G1, S, G2.
- DNA doubles and creates exact replicas of itself
- DNA is in the form of chromatin
Prophase
- Chromatids attach at the centromere (to make the X & Y shape)
- Nucleus breaks down and disappears
- two centrioles become visible and go to opposite sides of the cell
- spindle fibres radiate from the centrioles.
Metaphase
- each centromere is attached to a spindle fibre.
Anaphase
- Chromatin seperate at the centromere (are now called chromosomes)
- the cell begins to seperate.
Telophase
- a nuclear membrane forms around the two seperate groups of chromosomes
- the two daughter cells form their own nucleus
- spindle fibres disappear
Cytokinesis
- the complete separation of the cytoplasm
- two daughter cells have formed
- now in interphase (G1)
Explain the process of meiosis
The first division - IPMATC
During prophase, the chromosomes pair up with a homologous chromosome (identical chromosome). Therefore, during anaphase, the pairs of homologous chromosomes are seperate rather than the chromatids themselves.
It creates two diploid cells.
The second division - IPMATC
The same as mitosis
Makes four haploid cells
What are key similarities and differences between mitosis and meioses?
SIMILARITIES
- both have one duplication of chromosomes
- both create daughter cells
DIFFERENCES
- mitosis only has one nuclear division where as meiosis has two.
- mitosis produces two diploid cells where as meiosis produces four haploid cells.
- mitosis DNA stays the same, meiosis DNA is changed due to crossing over.
What is the difference between haploid and diploid cells?
Cells with two sets of chromosomes are called diploid.
Cells with one set of chromosomes are called haploid
