Question

1. What happens at G₂ of Interphase in preparation for mitosis? G1? S?.

2. Describe cytokinesis and Plant and Animal cells

Answer 1

1)

G2 of interphase

- it is the second growth phase, a part of interphase.

- also referred to as the pre-mitotic or post-synthetic phase.

- growth of the nucleus is observed at this stage.

- energy stores also increases, as they are needed for cell divisions.

- Intensive formation of RNAs and proteins are also observed at this stage.

- organelles like mitochondria and plastids undergo division.

- At the centriole, centrosome replicates.

- for structures associate with cell division and spindle fibers, the biochemicals gets formed.

G1 phase

- it is the first growth phase in interphase.

- also referred to as post-mitotic or pre synthetic phase.

- characterized by an increase in cell size.

- the intensive formation of cell organelles and biochemicals are observed at this stage.

- histone formation occurs.

- thus preparing the cell for DNA replication.

- in interphase - the most time is spent in this phase

S phase

- it is called a synthetic phase because DNA doubling occurs at this phase.

- assembling of kinetochores are observed.

- thus at the end there will be two chromatids per chromosome observed, which is get attached to each other.

- nonhistone and histone proteins synthesis occurs.

- it is also called invisible stage of the M phase.

- second most time spend in this phase.