Ch. 5.1-5.3 Binary Fission & Mitosis Ch. 5.4 Cell Cycle Regulation and Cancer Flashcards
What are two stages of Cell Division in ‘Prokaryotes’?
- Copy the DNA which is ‘replication’
- Split the cell in two to form daughter cells which is ‘Binary Fission’
Where is hereditary information stored in ‘Prokaryote’?
DNA
The ‘Prokaryotic’ chromosome is
Single Circle of DNA
‘Prokaryotic’ DNA replication begins with
unzipping of double stranded DNA at point called ‘origin of replication’
‘Prokaryotic’ new DNA double helix is formed by
adding complementary nucleotides to the exposed DNA strand that has been unzipped
What is binary fission?
the process of Cell grows and splits in two after the replication
What is genetic variation for Asexual Reproduction and sexual reproduction?
Asexual reproduction=clones=no genetic diversity
Sexual reproduction=genetic diversity
Bacteria’s (Prokaryote) adaptation replies on
genetic diversity
Bacteria(Prokaryote) use these 3 mechanisms for increasing generic variation other than sexual reproduction
- Conjugation 2. Transformation 3. transduction
What is Conjugation?
acquire DNA from other bacteria(pili)
What is transformation?
acquire DNA from surroundings
What is transduction?
acquire DNA from viruses
How is DNA packaged in Eukaryotic cell?
DNA in eukaryotic cell is linear and packaged into compact chromosome
What are 2 mechanisms for Eukaryotic cells to divide the DNA
Mitosis and meiosis
What is mitosis?
Cell division mechanism that occurs in somatic cells
What is meiosis?
Cell division mechanism that occurs in germ cells
What is the example of germ cells and number of chromosomes in germ cells?
23 chromosomes for Sperm, Ovum(egg) & 46 chromosomes(haploid) for fertilized egg
What is the example of somatic cells and number of chromosomes in somatic cells?
Blood cells, skeletal/muscle cells, stem cells, neuron cells…etc(all other cells except the germ cells) & 46 chromosomes(Diploid)
What are distinct phases for eukaryotic cell cycle
Interphase (G1, S, and G2 phases), Mitosis (M phase), and Cytokinesis (C phase)
Explain the interphase of eukaryotic cell cycle for mitosis
G1: Period of cell growth before DNA replicates
S: Period when DNA replicates and chromosomal proteins are duplicated
G2: Period after DNA replicates, cell prepares for division
Explain the Mitosis of eukaryotic cell cycle for mitosis
M Phase: Prophase, metaphase, anaphase, and telophase
What are alleles?
Homologous chromosomes containing same gene but may have different variation of those genes (Unduplicated)
What are sister chromatids?
Result of DNA replication that is exactly the same
What is a centromere?
Structure that sister chromatids are joined
How many pairs of homologous chromosomes do humans have?
Humans have 23 pairs of homologous chromosomes (total of 46 chromosomes, 92 chromosomes if they are replicated)
What is a karyotype?
Karyotype is an arrangement of chromosomes
What does interphase do?
Interphase sets the stage for cell division; Chromosomes are duplicated
What does condensation mean in interphase?
Chromosomes wind up tightly in progress
What is mitosis of cell cycle?
Mitosis is division of nuclear contents
What are the stages of mitosis
- Prophase 2. Interphase 3. Anaphase 4. Telophase
Explain the prophase of Mitosis
- Condensed chromosomes become visible
- Nuclear Envelope begins to disintegrate (break up).
- Nucleolus disappears
- Centrioles separate in the center of the cell and migrate to opposite ends (Poles) of cells
What does centrioles do in the prophase of mitosis?
The centrioles start to from a network of ‘spindle fibers’
Each cable in the ‘spindle fibers’ is made of ‘microtubules’
‘Microtubles’ grow from each pole until it is attatched to a centromere at a disc of protein called a ‘kinetochore’
Explain the metaphase of Mitosis
- The chrosomes attatched to microtubules of the spindles are alligned in the center of the cell
- The centromers are alligned along a imagenary plane which cuts cells in half, and this is called equotorial plane
Explain the anaphase of Mitosis
- Sister chromatids separate; Enzyme breaks the cohensin and the kinetochores
- The microtubules of the spindle is dismantled; it pulls chromatids toward the pole
Explain the telophase of Mitosis
- Spindle is dismantled
- A nuclear envelope froms around the set of chromosome at each pole
- The chromosomes begin to become uncondensed
- Nucleolous reappears
Explain the cytokinesis of Mitosis
The cytokinesis occurs at the end of mitosis and is a division of the cytoplasm into half
How does cytokinesis occur in animals and how is it evident?
It occurs by actin filaments contracting and pinching cells in two
It is evident because there is cleavage furrow between the daughter cells
How is cell cycle controlled?
Cell cycle is controlled by checkpoints which ensure previous phase is completed before advancing to next phase
What are 3 principal check points in eurokaryotic cell cycle?
G1, G2, and M checkpoints
What is G1 checkpoint?
Checkpoint determining whether cell divides and enters S phase
What is G2 checkpoint?
This checkpoint leads to mitosis
What is M checkpoint?
M checkpoint occurs during metaphase of mitosis and it triggers it exit M phase and advance to G1 phase
What is cancer?
Cancer is growth disoder of cells
What is benign tumors?
Benign tumors are surrounded by healthy layers and do not spread into other areas
What is Malignant tumors?
It does not have layers and spread into other areas to form new tumors; These cells are called metastaes
What are proto-ocogenes?
Proto-ocognes encode the protein that stimulate cell division; Mutations to these genes may cause cell division excessivley and that will be called ocognes
What are Tumor surpressure genes?
Tumor surpressure genes turn off cell division in healthy cells and it leads to uncontrolled cell division if it is mutated
What is p53 and what does p53 do?
p53 is gene that affects G1 checkpoint and it checks abnormal DNA to prevent it from cell division with damaged DNA; if this gene is damaged, it may allow cell division unchecked
What are phytochemicals?
Phytochemicals regulate our immune reponse, decrease angiogenesis, or antioxidants preventing radical molecules; Those can be found in food
