Cell Cycles. Mitosis & Meiosis, Karyotyping and Nondisjunction Flashcards
What is the order of the cell cycle?
Interphase (G1, S Phase, G2)-> Mitosis-> Cytokinesis
What is the order of the cell cycle?
Interphase (G1, S Phase, G2)-> Mitosis-> Cytokinesis
What happens in interphase?
The cell appears to be at rest. G1, S Phase and G2 occur in interphase. The nucleus is NOT dividing. 90% of a cells life
What happens in G1?
Cell growth in size and mass, protein synthesis also occurs at this time.
What happens in S phase?
Synthesis phase is the replication of the cells DNA. Each chromosome is duplicated and is given a so-called “Chromatid”
What happens in G2?
The cell manufactures the materials which are needed form mitosis and protein in made
What are the differences between chromatin and chromosomes?
Chromatin: Non-condensed form of genetic material, long and stringy material in the nucleus (Cell is NOT dividing)
Chromosomes: short condensed double stranded genetic material (Cell is dividing)
What are the difference between chromosomes and chromatid?
Chromosomes: short condensed double stranded genetic material (Cell is dividing)
Chromatid: Single stranded genetic material -> the result of mitosis
What occurs in Prophase?
Chromatin condenses and become visible as chromosomes, fibres extend and attach to centromeres, centrioles move to opposite poles of cell, spindle fibres form, nucleus disappears
What is the order of mitosis?
Interphase-> prophase-> metaphase-> anaphase-> telophase. 10% of a cells life
What occurs in Prophase?
Chromatin condenses and become visible as chromosomes, fibres extend and attach to centromeres, centrioles move to opposite poles of cell, spindle fibres form, nucleus disappears
What occurs in Metaphase?
Spindle fibres align chromosomes alone metaphase plate,
What occurs in Anaphase?
Chromosomes are separated at centromeres, move to opposite poles, are now chromatids
What occurs in Telophase?
Chromatids arrive at opposite poles and become chromatins again, nucleoli form, spindle fibres disperse, cells pinch off into two, cytokinesis begins
What occurs in Cytokinesis in animals vs plants?
Animals: cleavage furrow forms which splits the cell in two
Plants: Cell plate forms and splits the cell in two
Sex Cell vs. Somatic Cell
Sex Cell: Is a sperm or egg cell that has 23 chromosomes, a Haploid. Which is represented by n
Somatic Cell: is any body cell that has 46 chromosomes, a Diploid. Which is represented by 2n
Sex Chromsome vs. Autosomes
Sex Chromsomes: is the xx=girl or the xy=boy this the the 23rd pair of chromosomes in an egg or sperm cell
Autosomes: is number 1-22 pairs of chromosomes that determine your traits like hair and eye colour
What does Ploidy mean?
The number of sets of chromosomes in a cell. If it is a gamete cell (egg or sperm) it would have 23 so the ploidy would be n or haploid. If it was a somatic cell it would have 46 so the ploidy would be 2n or diploid
What is Apoptosis and why would it occur?
Programmed cell death. It can occur because a cell doesn’t pass a certain checkpoint and G1, G2 or Mitosis or it can occur naturally like what an embryo gets rid of webbed fingers and feet, the cell dies automatically.
What phases of the cell cycle are most likely to be shortened in the cancerous skin cell?
Interphase (especially G1 & G2) are shortened because the cell is devoting more time to mitosis (division) and less time to normal actives.
What are telomeres?
They are caps at the end of chromosomes that limit the amount of times a cell can undergo division
What technologies can test for cancer? What are treatments for cancer?
CT scan, blood count, biopsy of a tumour, chest X-rays. Surgical removal of tumour, radiation, chemotherapy
What are the advantages and disadvantages of asexual reproduction?
Advantages: Fast, less energy required, only need 1 parent
Disadvantages: No genetic diversity and can’t adapt to new environments
What are homologous chromosomes?
1 homologous pair of chromosomes (2) can come in double stranded homologous chromosomes to become 4 (tetrad)
