Question

which of these has occurred by the end of prophase? (check all that apply)
sister chromatids have separated.
the chromosomes are lined up in the middle.
the nuclear membrane has disappeared.
organelles have been divided between the 2 cells
the chromosomes have condensed and become visible
centrioles and spindle fibers have appeared
the cell membrane has begun to pinch inward.
what are the 3 main phases of the cell cycle?
interphase, mitosis, cytokinesis
interphase, prophase, anaphase
s phase, metaphase, cytokinesis
g1, s, g2
prophase, anaphase, telophase
replication, translation, and transcription

Explanation:

• First question:
• Sister chromatids separate in anaphase, not prophase.
• Chromosomes line up in the middle in metaphase.
• Organelles divide during cytokinesis.
• Cell - membrane pinching inward occurs in cytokinesis.
• In prophase, the nuclear membrane disappears, chromosomes condense and become visible, and centrioles and spindle fibers appear.
• Second question:
• The three main phases of the cell cycle are interphase (where the cell grows and replicates DNA), mitosis (nuclear division), and cytokinesis (cytoplasmic division).
• Prophase and anaphase are stages within mitosis.
• S phase is part of interphase, and metaphase is a stage of mitosis.
• G1, S, G2 are sub - phases of interphase.
• Replication is part of interphase (S phase), and translation and transcription are processes related to gene expression, not cell - cycle phases.

Answer:

• First question: The nuclear membrane has disappeared; The chromosomes have condensed and become visible; Centrioles and spindle fibers have appeared.
• Second question: interphase, mitosis, cytokinesis.