3.2.2- Cells arise from other cells

Question 1

Cell division in eukaryotes vs prokaryotes vs viruses=

Answer 1

E= cells enter cell cycle & divide by mitosis or meiosis
P= cells replicate by binary fission
V= replicate inside host cells they invade by injecting their nucleic acid> cell to replicate virus particles

Question 2

Phases of cell cycle=

Answer 2

1) interphase (cell grows & DNA replicated)

2) Mitotic phase (replicated DNA & cytoplasmic contents separated & cells divide)

Question 3

Interphase- process

Answer 3

1) G1- cell grows
2) S- DNA synthesis
3) G2- cell grows more (& error check phase)

Question 4

Mitosis phases (5)

Answer 4

Prophase= Nucleolus disappears, chromatin C> chromosomes
Centrioles move to opposite poles & microtubules form mitotic spindle

Metaphase= Chromosomes line up along mid-line of cell & attached to spindle by centromere

Anaphase=Chromosomes break> 2 chromatids, Chromatids pulled by spindles contracting to each pole

Telophase= Chromatids reach opposite poles& begin to decondense, nuclear envelope form around to form nuclei

Cytokinesis

Question 5

features of mitosis (3)

Answer 5

genetically identical cells are made
diploid cells are made
used for growth and repair

Question 6

Binary fission

Answer 6

replication of circular DNA & plasmids

Division of cytoplasm> 2 daughter cells (each with 1x circular DNA & variable no of plasmids)

Question 7

mitotic index=

Answer 7

mitotic index= (no of cells in mitosis/ total no of cells) x 100