Biology Flashcards
What is in interphase
G1 phase
G2 phase
S phase
Mitosis
Cytokines
What is involved in the G1 and G2 phase
G1 - metabolic activity and growth
G2 - metabolic activity growth and preparation for cell division
What happens In S phase
Metabolic activity and growth and DNA synthesis
What happens in mitosis and cytokines
Mitosis- distribution of chromosomes into two daughter nuclei
Cytokines- the division of the cytoplasm producing two daughter cells ( each cell can produce a new cycle)
What happens in the g2 of interphase in a animal cell
- nuclear envelope enclosed in the nucleus
- the nucleus contains one or more nucleoli
- two Centrosomes have formed by duplication of a single centrosome/ centrosome regions in animal cells that organize the microtubules of the spindle. Each centrosome contains two centrioles
- chromosomes duplicate during a phase cannot be seen individually bc they are not dense yet
What happens in prophase in a animal cell
- chromatin fibers become tighter coils and are observe able with a light microscope
- nucleoli disappear
- each duplicate chromosome are two identical sister chromatids joined at their centromeres
- mitotic spindle begins to form/ composed of centrosomes and microtubules that extend form them/ radial arrays of shorter microtubules that extend from the centrosomes are called asters
- centrosomes move away from each other : propelled partly by the lengthening microtubules between them
What happens in the pro metaphase in the animal cell
-Nuclear envelope fragments
-microtubules extend ed from centrosomes invade the nuclear area
- kinetochore ( specialized protein) now formed at centromere of each chromatid ( two per chromosome)
- some microtubules attach to the kinetochores jerk the chromosomes back and forth
- nonkinetochore microtubules interacts with those from opposite pole of the spindle lengthening the cell
What happens in metaphase in a animal cell
- the centrosomes now at opposite poles of cell
- chromosomes all arrives at the metaphase plate ( plane that is equidistant between the spindles ) the chromosomes centremeres lie at the metaphase plate
- each chromosome the kinetochore microtubules coming from opposite poles
What happens in Anaphase in animals cell
Shortest stage
- cohesion proteins are cleaved / allows two sister chromatids are parted suddenly and each become independent chromosomes
- two new daughter chromosome begin to move towards opposite ends of the cell ( their kinetochore microtubules are shortened because the microtubules are attached to the centromere region) centromeres are pulled ahead of the arms
- cell elongates as the nonkinetochores microtubules lengthen
- end of anaphase the two ends of cell have equivalent and complete collections of chromosomes
What happens in telophase if an animal cell
- two daughter nuclei form in cell. / nuclear envelopes arise form fragments of the patent cells nuclear envelope and other portions of the endomembrane system
-nucleoli reappear - chromosome become less dense
- any remaining spindle microtubules are depolymerized
- mitosis ( division of one nucleus into two genetically identical nuclei are now complete)
What happens in a cytokines in a animal cell
- division of cytoplasm is usually well under way by late telophase so two daughter cells appear shortly after the end of mitosis
- animal cells, cytokines involves the formation of a cleavage furrow, which pinches the cell in two
What happens in the interphase of meiosis
- pair of homologous chromosomes in diploid parent cells
- chromosomes are duplicated
- diploid cell had the duplicated chromosomes
What happens in Meiosis 1
Homologous chromosomes are separated
- haploid cells have duplicated chromosomes
What happens in meiosis 2
Sister chromatids are separated
- haploid cells have no duplicated chromosomes
