W1LAB - Genetic aspects of atypical mitosis and meiosis

Question 1

What are the phases of cell cycle?

Answer 1

Interphase: G1, S, G2
Prophase
Metaphase
Anaphase
Telophase

Question 2

What are the phases of typical mitosis?

Answer 2

Question 3

Give the structure of chromosome

Answer 3

Question 4

Give the number of DNA content and chromosomal number of this haploid cell through each phase

Answer 4

Question 5

Describe the Structure of mitotic spindle

Answer 5

Question 6

What are the 7 types of mitosis?

Answer 6

1. Typical
2. Atypical
3. Endomitosis (endoreduplication)
4. No cytokinesis
5. Multipolar division
6. Bridge formation
7. Non-disjunction

Question 7

What are the consequences of typical and atypical types of mitosis?

Answer 7

1. Typical -> Genetically identical cells.
2. Atypical -> Genetically not identical cells (In multicellular organism causes mosaicism)

Question 8

What is the description of Endomitosis (Endoreduplication)?

Answer 8

DNA is duplicated, but during M-phase the nuclear envelope remains intact.
1) No separation of chromatids
2) Separation of chromatids

Question 9

What are the consequences of Endomitosis (Endoreduplication)?

Answer 9

• Giant cell, giant nucleus
• Polythene (giant) chromosomes (if there is No separation of chromatids)
• More chromosomes (polyploid cell) <- if there is Separation of chromatids

Question 10

What is this?

Answer 10

Polythene (giant) chromosomes
-> consequence of endomitosis

Question 11

What is this?

Answer 11

giant cell derived by endomitosis
(a consequence of Endomitosis)

Question 12

What are the consequence and description of mitosis which has no cytokinesis?

Answer 12

• Description: Mitosis is not followed by cytokinesis.
• Consequence: Multinucleated (giant) cells.

Question 13

What are the consequence and description of mitosis which has Multipolar division?

Answer 13

• Description: Due to atypical duplication and division of centrosome chromosomes are pulled to more than two poles
• Consequence: abnormal chromosome number
  in the arising cells.

Question 14

What is this?

Answer 14

Tripolar metaphase

Question 15

What is this?

Answer 15

Tripolar metaphase

Question 16

What are the 3 consequences of mitotic spindle errors?

Answer 16

1. Anaphase-lag
2. Non-disjunction
3. Bridge formation

Question 17

What is the consequence of bridge formation?

Answer 17

Acentric fragment
-> Cause micronucleis

Question 18

What are the consequence and description of mitosis which has Bridge formation?

Answer 18

• Description: A chromatid is pulled from two poles.
• Consequence: Breakage of chromosome (structural chromosomal aberration)

Question 19

What are the consequence and description of mitosis which has Mitotic Non-disjunction?

Answer 19

• Description: Lack of kinetochor microtubules attachment to a chromatid.
• Consequence: abnormal chromosome number

Question 20

What is the result of meiosis?

Answer 20

4 genetically different haploid cells

Question 21

What are the essentials of meiosis?

Answer 21

• Two divisions – meiosis I and II
• Chromosome number is halved
• Genetic variability – homologous recombination - independent assortment of chromosomes
  => synapsis

Question 22

Give the numbers of DNA content and chromosome number of this cell?

Answer 22

Question 23

What is the cause of aneuploid genom mutations?

Answer 23

Meiotic nondisjunction

Question 24

Describe Meiotic non-disjunction

Answer 24

• Results of meiotic I and meiotic II non-disjunction are different
• Meiotic non-disjunction may occur both in oogenesis and spermatogenesis BUT MORE FREQUENT IN OOGENESIS
• Sex chromosome non-disjunction is more frequent in spermatogenesis

Question 25

Typical and atypical mitotic phases in cell culture 52. HeLa monolayer (MGG) -> Identify

Answer 25

1 = early prophase 2 = metaphase (side view).

Question 26

Typical and atypical mitotic phases in cell culture 52. HeLa monolayer (MGG) -> Identify

Answer 26

1 = metaphase (from above) 2 = metaphase (side view).

Question 27

Typical and atypical mitotic phases in cell culture 52. HeLa monolayer (MGG) -> Identify

Answer 27

1 = telophase 3 = metaphase (side view) 4 = telophase

Question 28

Typical and atypical mitotic phases in cell culture 52. HeLa monolayer (MGG) -> Identify

Answer 28

1 = anaphase.

Question 29

Typical and atypical mitotic phases in cell culture 52. HeLa monolayer (MGG) -> Identify

Answer 29

1 = multinucleated cells 2 = nucleus with many nucleoli 3 = cytoplasm.

Question 30

Typical and atypical mitotic phases in cell culture 52. HeLa monolayer (MGG) -> Identify

Answer 30

1 = giant cell derived by endomitosis

Question 31

Typical and atypical mitotic phases in cell culture 52. HeLa monolayer (MGG) -> Identify

Answer 31

1 = anaphase bridge

Question 32

Typical and atypical mitotic phases in cell culture 52. HeLa monolayer (MGG) -> Identify

Answer 32

1 = tetrapolar mitosis, metaphase 2 = nucleus 3 = cytoplasm (binucleated cell)

Question 33

Typical and atypical mitotic phases in cell culture 52. HeLa monolayer (MGG) -> Identify

Answer 33

1 = metaphase 2 = tripolar metaphase 3 = acentric fragment 4 = cytoplasm 5 = interphase nucleus with nucleoli.

Question 34

Give Number of DNA molecules in one cell

Answer 34

Question 35

Give the Number of chromosomes in one cell

Answer 35

Question 36

Give the Number of chromatids in chromosome

Answer 36

Question 37

Give the number of Ploidy

Answer 37

Question 38

What is true for the ploidy during meiosis I.?

Answer 38