Topic 4: The Cell Cycle, Mitosis, Meiosis

Question 1

sex chromosomes

Answer 1

• 23
• contain genes that determine sex

Question 3

autosomal chromosomes

Answer 3

• 1 - 22
• contain genes for somatic characteristics
• each autosomal chromosome pair is not identical but equivalent = homologous chromosome

Question 4

Interphase: G1 phase

Answer 4

• growth, metabolism
• at end of G₁, centrosomes replicate
• note: in some cells that do not divide again once mature (example: remain in G₁₎ - in these cells it is termed G₀ phase
  
  • example: nerve + some muscle cells

Question 5

Interphase: G₁ phase

• g______, m______
• what replicates at end of G₁?
• note: in osome cells that do not divide again once mater - in these cells it is termed ______ phase.

Answer 5

• growth, metabolism
• at end of G₁, centrosomes replicate
• note: in some cells that do not divide again once mature (example: remain in G₁) - in these cells it is termed G_o phase
  
  • example: nerve + some muscle cells

Question 6

Interphase: S phase

Answer 6

• chromosomes replicate, but are still present as chromatin (not individually visible)
• ALWAYS occurs before division (mitosis and meiosis)
• replicates are called sister chromatids

Question 7

Interphase: S phase

• replicates are called sister chromatids
  
  • ?
  • ?
    
    • kinetochore = ?

Answer 7

• attached to each other at an area of DNA called the centromere
• kinetochore proteins (produced during S phase) attach to each centromere to form the kinetochore ( = protein + DNA complex, 1/chromatid)
  
  • kinetochore = site of attachment of spindle microtubules

Question 8

Interphase: G₂ phase

Answer 8

• growth, metabolism
• production of enzymes and other proteins needed for cell division

Question 9

kinetochore

Answer 9

site of attachment of spindle microtubules

Question 10

kinetochore is composed of?

Answer 10

• protein
• DNA complex
• 1/chromatid

Question 11

kinetochore proteins are produced during what phase?

Answer 11

S phase

Question 12

mitotic phase

involves:

Answer 12

• mitosis = division of nuclear material (chromosomes)
  
  • 4 phases, but continuous cycle
    
    • PMAT
• cytokinesis = division of cytoplasm

Question 13

division of nuclear material

Answer 13

mitosis

Question 14

division of cytoplasm

Answer 14

cytokineses

Question 15

mitotic phase

when mitotic phase ends:

Answer 15

• mitosis & cytokinesis complete
• daughter cell go into interphase (G₁)
• cycle starts over

Question 16

site of attachment of spindle microtubules

Answer 16

kinetochore

Question 17

Somatic cell formation: mitosis

Prophase

Answer 17

• chromosomes condense from chromatin form - become individually visible
• nucleoli/nuclear envelope disappear
• centrosomes move to either pole
• microtubules form spindle apparatus (starting at centrosomes) + attach to kinetichore proteins (Called kinetochore microtubules)
  
  • spindle moves chromosomes toward cell equator

Question 18

Somatic cell formation: mitosis

Prophase

chromosomes ________ (thicken, coil) from _______ form - become __________ _____

Answer 18

chromosomes condense (thicken, coil) from chromatin form - become individually visible

Question 19

Somatic cell formation:

prophase

nucleoli/nuclear envelope _______

Answer 19

nucleoli/nuclear envelope disappear

Question 20

Somatic cell formation: mitosis

Prophase

centrosomes ________________

Answer 20

centrosomes move to either pole

Question 21

Somatic cell formation: mitosis

Prophase

• kinetochore proteins (called ______________)
• spindle moves chromosomes to___________

Answer 21

• called kinetochore microtubules
  
  • ​spindle moves chromosomes toward cell equator

Question 22

Somatic cell formation

Metaphase

Answer 22

46 chromosomes line up on cell equator

Question 23

Somatic cell formation

Anaphase

Answer 23

• as the spindle microtubules shorten, the kinetochores are pulled away from each other - causing separation of centromeres, which results in separation of the chromatids
• 46 chromatids migrate to each pole
• cytokinesis (division of cytoplasm begins)

Question 24

cytokinesis begins at what phase of mitosis?

Answer 24

anaphase

Question 25

46 chromatids migrate to each pole occurs during what phase of mitosis?

Answer 25

anaphase

Question 26

as spindle microtubules shorten, the kinetochores are pulled away from each other - causing separation of centromeres, which results in separation of the chromatids occurs during what phase of mitosis?

Answer 26

anaphase

Question 27

46 chromosomes line up on cell equator occurs during what phase of mitosis?

Answer 27

metaphase

Question 28

nucleoli/nuclear envelope dissapears during what phase of mitosis?

Answer 28

prophase

Question 29

microtubules form spindle apparatus and attach to kinetochore proteins occurs during what phase of mitosis?

Answer 29

prophase

Question 30

chromosomes condense from chromatin form - become individually visible refers to what phase of mitosis?

Answer 30

prophase

Question 31

centrosomes move to either pole refers to what phase of mitosis?

Answer 31

prophase

Question 32

somatic cell division: mitosis

Telophase

Answer 32

• chromosomes uncoil to chromatin
• nucleoli, nuclear envelope reappear
• spindle disassembles
• cytokinesis completes (or may end after telophase ends)

Question 33

chromosomes uncoil to chromatin refers to what phase of mitosis?

Answer 33

telophase

Question 34

nucleoli, nuclear envelope reappear refers to what phase of mitosis?

Answer 34

telophase

Question 35

spindle disassembles refers to what phase of mitosis?

Answer 35

telophase

Question 36

cytokiesis completes refers to what phase of mitosis?

Answer 36

telophase