Mitosis and Meiosis Flashcards
What are the differences in the RESULT of meiosis and mitosis?
For meiosis, the results are 4 haploid daughter cells that are non-identical to the parent or one another. For mitosis it’s 2 diploid daughter cells that are indentical to the parent and one another.
What happens in interphase
Cell growth, DNA replicated, organelles grow.
What’s unique in prophase 1 for meiosis? Explain
Crossing over happens. This happens when homologous pairs of chromosomes (one from father, one from mother) line up and parts are exchanged.
What happens during prophase for mitosis?
Chromatin condenses into chromosomes, nuclear membrane breaks apart
What are haploid and diploid cells. What’s the difference?
Haploid: one set of chromosomes, “n” chromosomes, gametes.
Diploid: 2 sets of chromosomes, “2n”, somatic.
What phase is it when the chromosomes are pulled apart?
Anaphase.
What prevents the cell from getting smaller and smaller between each division?
Cells grow to maintain their size between each division.
Why does the cell need to duplicate it’s DNA?
To make sure each daughter cell receives the complete copy of the parent’s DNA.
What happens in cytokinesis?
The sides of the cell pinch inwards, dividing the cell into 2.
What reappears in telophase? Why does it go away through the first 3 steps of mitosis?
The nuclear membrane. So, the chromatids can be pulled to the sides of the cell.
What’s the purpose of Mitosis?
Growth: increase # of cells
Repair wounds: To repair parts of the body that have been acidently damaged. Ex. injuries
In meiosis what’s the difference between anaphase 1 and 2?
In anaphase 1, homologous chromosomes separate when pulled apart to the opposite poles of the cell, but sister chromatids stay together. In anaphase 2, sister chromatids are pulled apart.
Why don’t red blood cells perform mitosis?
Because they don’t have a nucleus. They don’t have a nucleus because they need room to transport oxygen.
What’s the only way to make gametes?
Meiosis
What happens during anaphase for mitosis?
sister chromatids are pulled apart to the opposite poles of the cells by spindles.
How many chromatids are there before interphase, after interphase and after mitosis?
46, 92, 46.
How many chromosomes are there before interphase, after interphase, after meiosis 1 and after meiosis 2?
46, 46, 23, 23
What is the relationship between chromatin and chromosomes?
Chromatin condenses to form chromosomes. They’re made up of the same material: DNA.
During what phase does the spindle form?
Prophase.
During metaphase, the chromosomes line up along the…
equator
What are homologous chromosomes?
Homologous chromosomes are 2 chromosomes that are similar in length and gene order. One comes from the mother and the other comes from the mother
What are sister chromatids?
2 chromatids joined at a centromere that are identical to one another
What is uncoiled DNA called?
Chromatin
what is # does “n” refer to for humans?
23
What does crossing over benefit?
genetic diversity because parts of the father’s and mother’s chromosome are exchanged.
Why don’t we do crossing over in mitosis?
It’s because the goal of mitosis is to make identical cells, not to make different cells. (Crossing over results in non-identical cells)
What happens during metaphase?
Chromosomes line up at the equator of the cell and each centromere of the chromosome attaches itself to a spindle fibre.
Why doesn’t the DNA replicated before prophase 2?
because it would create diploid cells instead of haploid cells.
The cytoplasm splits into 2 identical daughter cells during this process:
Telophase
What are amitotic cells? Examples?
Cells that can’t reproduce through mitosis. RBC, nerve cells in spinal cord.
