Reproductive system Flashcards
What is mitosis
It is a type of cell division which results in two daughter cells having the same number and kind of chromosomes as the parent nucleus
It is necessary fro growth and tissue repair
What is meiosis
It is a type of cell division for producing gametes which are haploid sex cells
Here, each cell divides twice into 4 daughter cells. This is different to mitosis as the daughter cells aren’t the same as the parent cells due to the idea of crossing over of the chromosomes
What is interphase
Duplicating chromatids to get a chromosome at 1 centromere (2 chromatids at 1 centromere), compared to just 1 chromatid at 1 centromere previously
What is the approach which is common in both mitosis and meiosis
PMAT (Prophase, metaphase, anaphase, telophase)
However, in meiosis, pmat happens twice whereas in mitosis it only happens once
Explain the process of prophase in mitosis
Chromosomes in the cell nucleus start to condense together in preparation for cell division
Nucleus is still available
Mitotic spindles begin to appear
Explain the process of metaphase in mitosis
Nucleus has been disassembled
Chromosomes are lined up singularly(i think) singleline
Explain the process of anaphase in mitosis
Chromosomes separate and move towards poles of the cell, with assistance from the mitotic spindles
Explain the process of telophase in mitosis
New nuclei starts to form around the separated chromosomes
Each new daughter cell is a diploid cell containing 46 chromosomes each
What is cytokineses
Final separation where cytoplasm is severed to leave two identical cells
Explain the process of Prophase 1 in meiosis
Same process as mitosis prophase, however CROSSING OVER can occur, where random sharing of genes can occur between chromosomes –> increased genetic variation
Explain the process of metaphase 1 in meiosis
Same process as mitosis however some chromosomes may have crossed over.
Nucleus has been disassembled and the chromosomes are lined up in the middle of the cell with mitotic spindles connected
ADditionally, the chromosomes here are lined up in their homologus pairs –> when separation occurs it splits into 23
Explain the process of anaphase 1 in meiosis
Same process as anaphase in mitosis
Chromosomes separate and move towards the poles of the cell
Explain the process of telophase 1 in meiosis
Same as mitosis telophase
New nuclei starts to form around separated chromosomes
Explain the function of cytokinesis in meiosis
It separates where cytoplasm is severed to leave remaining two cells
Explain the process of prophase 2 in meiosis
Same function as prophase 1 but no crossing over
Explain the process of metaphase 2 in meiosis
Chromosomes don’t line up in pairs but are single file
As a result, whe they divide they become haploid (23 chromosomes) rather than diploid (46 chromosomes)
Explain the process of anaphase 2 in meiosis
chromatids (half) are pulled away fro centre of cells not the chromosomes (full)