PP 9 Meiosis & Mitosis Flashcards
- How many divisions does it take to complete mitosis, meiosis?
- Do homologous chromosomes crossover in mitosis, meiosis if so what phase?
- When do centromeres divide in meiosis,mitosis?
- what does meiosis generates? Mitosis?
- Which process results in copying and growth? Which is necessary for sexual reproduction?
- Do the daughter cells in mitosis have diff. Genetic info as parent, meiosis?
- Do daughter cells have the same # of chromosomes as parent cells?
- 1- mitosis/ 2- meiosis
- -do not cross over in mitosis/ Do in meiosis. Prophase 1
- Mi/ centromeres divide in anaphase. Me/ centromeres divide in anaphase 2
- Mi/ generates body cells Me/ generates sex cells
- Mi/ copying & growth Me/ necessary for sexual reproduction
- Mi/ daughter cells have same genetic info. Me/ daughter cells are genetically diff. From parent
– Me/ daughter cells have half the # chromosomes as parent cell (haploid)
Mi/ daughter cells have same # of chromosomes as parent cell ( diploid)
What is cell division?
Grow & replace 2 fundamental qualities of life
Mitosis & binary fission are means of sexual or asexual reproduction?
Asexual (w/out sex)
The cell cycle consists of 3 parts, name them?
- interphase (G1, S, G2)
- Mitosis (Prophase, Metaphase, Anaphase, Telophase,)
- Cytokinesis ( cell splits & divides cytoplasm)
What does Mitosis do in multi-cellular organisms?
- causes growth by increasing # of cells
- replaces lost cells
- repairs injuries
Briefly explain what happens in each phase of Mitosis?
- Interphase/ cells growth, chromosomes double, cells grow some more
- Prophase/ chromosomes condense, nuclear membrane disappears, centrioles go to opposite ends of cell, spindle fiber forms
- Metaphase/ chromosomes move to middle, spindle fibers connect to centromere
- Anaphase/ centromeres pull apart, sister chromatids become separate, strait to move to opposite ends of poles of cell
- Telophase/ chromosomes uncoil, nuclear membrane forms, spindle fiber disappears
- Cytokinesis/ cell splits & cytoplasm divides
Cells spend 90% of their time in interphase. What happens in the 3 phases?
- G1/ cells grow
- S (synthesis)/ chromosomes double & divide to make identical pairs
- G2/ cells grow more & produce needed proteins necessary for cell division
2 classes of proteins code for checkpoint proteins, Name them, tell what they are used for?
- Proto-oncogen(yes) code for proteins that encourages cell division
- tumor suppressor gene (no) discourage cell division
Name phase. Of Mitosis, Meiosis 1, & Meiosis 2.
Mi (interphase,prophase,metaphase,anaphase,telophase,cytokinesis)
Me 1 (interphase 1, prophase 1, metaphase 1, anaphase 1, telophase 1, cytokinesis 1)
Me 2 ( prophase2, metaphase2, anaphase2, telophase2, cytokinesis2)
Mutagens are agents that damage what?, Give an example of a mutagen.
– DNA
- carcinogens cause mutations that lead to cancer.
Ex. Cigarette smoke
Define:
Somatic cells & Gametes, are they haploid or diploid.
– 2 sets of chromosomes, NOT SEX CELLS, DIPLOID (2N)
–1 set of chromosomes, SEX CELLS, haploid (N)
What causes cancer?
Failure to control cell division
Difference between determination & differentiated?
Determination- cell gets to pick what cell type it will pick
Differentiated- cell is developed in specific cell
Diploid cells have (2) sets of chromosomes, how many sets do you get from each parent?
One set from each parent
Define
Malignant & Benign tumor
M/ BAD TUMOR, cells invade organs & continue to grow
B/ mass of abnormalities that remain at the original spot. (DO NOT SPREAD)
What happens in Meiosis 1?
Same as mitosis, cells grow, CHROMOSOMES REPLICATE resulting in (2) haploid daughter cells.
Name the phases of Meiosis 1, what happens in each phase?
- Interphase 1/ cells grow, DNA & proteins replicate, cell grow some more
- Prophase 1/ nuclear membrane breaks down, centrioles go to opposite ends, spindle fiber forms
- Metaphase 1/ chromosomes attach to spindle fibers & line in middle
- Anaphase 1/ chromosomes pull part & move to opposite ends of cell
- Telophase 1/ chromosome gather at pole, nuclear membrane forms, cytoplasm divides
- Cytokinesis 1/ cell becomes 2.
Difference in homologous & non homologous chromosomes?
- Same # of genes along DNA
- different genes on DNA
Meiosis involves gamete(sex cells) production, how many divisions does it go through?
- 2 Meiosis 1 (just like mitosis) Meiosis 2 (cut in half)
Name 5 factors that create genetic diversity by creating new alleles.
- Mutation/ change in nucleotide sequence in DNA
- Crossing over/ Exchange of equal portions of DNA between homologous chromosomes
- Segregation/ chromosomes broken apart randomly
- Independent Assortment/ half is going to one end, other half is going to other end
- Fertilization/ eggs & sperm unite
What are the stages in Meiosis 2?
- Prophase 2/ nuclear membrane disappears, spindle fibers form
- Metaphase 2/ chromosomes line up in middle
- Anaphase 2/ centromeres divide, sister chromatids pull apart. Now called daughter chromosomes
- Telophase 2/ nuclear membrane forms, spindle fibers disappear, cell starts to pinch in middle
- Cytokinesis 2/ cells divide in 2
Define:
- Monosomy
- Trisomy
- cell has (1) of a given pair of chromosome
- cell has (3) copies of given chromosomes
What is Down syndrome?
- 3 copies of chromosome 21
- 47 chromosomes instead of 46
- symptoms inclement thickened eyelids, mental impairment, & faulty speech
