BIO REVISION- CELL CYCLES

What is cell replication?

The process whereby a parent cell divides to produce two genetically identical daughter cells.

What is the purpose of cell replication in multicellular organisms?

• Growth and development

• Maintenance and repair

• Reproduction

Draw out binary fission and describe the steps

draw it!

Why do Eukaryotes replicate?

• Growth

• Repair

• Reproduction

What is the longest phase of the cell cycle?

Interphase

What happens during mitosis?

Nucleus divides

What happens during cytokinesis?

Cytoplasm divides

What is interphase?

The first phase of the cell cycle. It begins immediately after the end of cell division.

Can be divided into three phases:

• G1 (1st growth phase)

• S (synthesis phase)

• G2 (2nd growth phase)

What is the purpose of G0?

To halt cell division temporarily or permanently, allowing cells to exit the cell cycle.

What is stage S?

Cell duplicates its DNA

What is G2?

• DNA proofreads

• Protein synthesizes

• Ensures that all is ready for mitosis is ready to proceed

What are the phases of Mitosis and what happens in them?

Prophase:

• Centrosomes move to opposite sides

• Nucleus is broken open

• Chromosomes become visible

• Spindle fibers are formed

Metaphase:

• Spindle fibers attach themselves to chromosomes

• Chromosomes form into a straight line in the center

Anaphase:

• Spindle fibers, attached to chromosomes, pull them to opposing sides.

• Chromsomes are now known as chromatids, now seperated

Telophase:

• Spindle fibers disappear

• Chromosomes decondense, becoming long thing chromatid fibres.

What is cytokinesis?

The division of the cytoplasm

What is the difference between mitosis and binary fission?