Cell Division

Question 1

Cell division

Answer 1

Set of processes a parent cell goes through to form daughter cells

Question 2

Diploid

Answer 2

Diploid cells have 2 copies of the chromosomes/ 2 complete sets.
23 chromosome pairs (46 chromosomes)

Question 3

Tetraploid

Answer 3

When a cell has 4 homologous sets of chromosomes

Question 4

Chromosome

Answer 4

Section of genome that is tightly coiled.

Question 5

Cell cycle

Answer 5

Describes the different phases a cell undergoes in life.
2 main phases: interphase & mitotic phase.
Occurs every 24-30h depending on cell

Question 6

Mitosis

Answer 6

Occurs regularly
Results in 2 diploid daughter cells (identical to mother cell)
Part of the cell cycle (mitotic phase).

Question 7

G0 phase

Answer 7

Interphase subphase.
The cell isn’t actively dividing, it’s just fullfiling it’s cellular duties/functions

Question 8

G1 phase

Answer 8

Growth phase.
Cell preparing for division. Grows, lots of protein synthesis (used for ➡️) organelles duplicated.
Stimulated by growth hormones/factors

Question 9

S phase

Answer 9

Synthesis phase. Copies of DNA are synthesises (parent cell diploid ➡️tetraploid, 2n ➡️4n). The centrosome (involved in mitosis) is duplicated..

Question 10

G2 phase

Answer 10

Final growth push. Organelle duplication occurs. Copied dna is checked for mistakes & corrected.

Question 11

Mitotic phase

Answer 11

Mitosis+ cytokinesis. Leads to 2 diploid daughter cells

Question 12

Prophase

Answer 12

*Chromatin condenses into chromatids.
*Chromatids find their copy and attach at the centromere (middle of chromatids) which forms sistercromatids.
*Nuclear envelope starts dissolving
*Centrosomes (made of centrioles) move to opposite sides of cell- begin to form spindle apparatus that attaches to centromere

Question 13

Metaphase

Answer 13

Spindle apparatus lines upp sistercromatids at equator. One chromosomes from each pair is faced towards each en of cell

Question 14

Anaphase

Answer 14

Chromatids are pulled apart at centromere - spindle apparatus shortens it’s fibers.
Each chromosomes pulled toward opposite sides of cell

Question 15

Telophase

Answer 15

*Chromosomes start to uncoil at the ends of the cell.
* 2 nuclear envelopes form around the 2 sets of DNA
* Spindle apparatus is broken down

Question 16

Cytokinesis

Answer 16

• cytoplasm divides into 2
  *Actin pinches cell in half
• New cell membrane is built
• Cell separates into 2 diploid daughter cells

Question 17

Chromatin

Answer 17

Dna wrapped around histone

Question 18

Sister chromatids

Answer 18

2 copies of exactly the same chromosome

Question 19

Centromere

Answer 19

Central point of chromosome where the sistercromatids are stuck together

Question 20

Centriole

Answer 20

Organelle in centrosome. Important for the build of kärnspolen som pulls apart the chromosomes during anaphase.

Question 21

Spindle apparatus

Answer 21

Series of microtubules. Attaches to centromere and later pulls apart sistercromatids

Question 22

Meiosis

Answer 22

Type of cell division necessary for sexual reproduction
Results in 4 genetically unique haploid daughter cells.
Also called reduction division (results in fewer chromosomes in cell)
Takes place in ovaries and testies.
Has 2Meiotic phases

Question 23

Prophase I

Answer 23

1: chromatin condenses into chromosomes
* Nuclear envelope breaks down
* Centrosomes move to opposite ends - spindle apparatus starts forming

Question 24

Metaphase I

Answer 24

Fibers form spindle attach to paired homologous chromosomes and then line up in pairs at equator.
Lines up in groups of 4 chromosomes/ 2 sister chromatids

Question 25

Anaphase I

Answer 25

Fibers from spindle apparatus shortens, chromosomes from each homologous pair are separated. *Sister chromatids pulled towards opposite ends of cell

Question 26

Telophase I

Answer 26

Spindle apparatus is broken down

Question 27

Homologous chromosomes

Answer 27

Chromosomes similar in size, shape and genetic coding. They pair up so that crossing over can happen

Question 28

Crossing over

Answer 28

2 sister chromatids that are homologous chromosomes have random parts of their genetic information swapped. Facilitated by enzymes. ➡️ Genetic diversity (also why genetically unique daughter cells)

Question 29

Gamete

Answer 29

Könscell (1n) Result of meiosis

Question 30

Reduction division

Answer 30

Meiosis. Called this because the daughter cells have fewer sets of chromosomes (1n)

Question 31

Haploid

Answer 31

Cell that only has 1 set of chromosomes

Question 32

Centrosome

Answer 32

Made of 2 centrioles. Forms spindle apparatus

Question 33

Prophase 2

Answer 33

*If necessary chromatin condenses into chromosomes and nuclear envelope breaks down *centrosomes move to opposite poles & spindle apparatus starts forming *Fibers from each pole of spindle apparatus attaches to sister chromatids If paus: new centrosomes. If not: splits in 2

Question 34

Metaphase 2

Answer 34

Sister chromatids line up individually at equator by fibers of spindle apparatus

Question 35

Anaphase 2

Answer 35

Fibers of spindle apparatus contract, separating sistercromatids and pulling to opposite ends of cell

Question 36

Telophase 2

Answer 36

*Nuclear envelope forms around each set of chromosomes *Chromosomes decondense