Cell Division

Question 1

what is the purpose of mitosis?

Answer 1

1. to produce genetically identical (clones) daughter cells for growth and asexual reproduction
2. to repair damages tissues
3. growth

Question 2

What happens during interphase?

Answer 2

1. cell engages in metabolic activity to prepare for mitosis
2. DNA is replicated
3. some organelles replicate

Question 3

What happens during prophase?

Answer 3

1. chromosomes condenses and becomes visible
2. centrioles move to opposite ends of the nucleus
3. spindles begin to form
4. nuclear envelope and nucleolus break down

Question 4

What is the cell cycle?

Answer 4

a cycle of divisions with intermediate growth periods

Question 5

what are the stages of the cell cycle?

Answer 5

1. interphase
2. mitosis or meiosis (if it’s a reproductive cell)
3. cytokenisis

Question 6

why does the cell cycle not occur in some cells?

Answer 6

after differentiation some cells in multicellular organisms no longer hjave the ability to divide

Question 7

What happens during metaphase?

Answer 7

1. sister chromatids line up at the equator
2. spindles attatch to the centromeres

Question 8

What happens during anaphase?

Answer 8

1. spindle fibres contract causing the sister chromatids to split into chromosomes and then be pulled to opposite poles
   2.spindle fibres break down

Question 9

What happens during telophase?

Answer 9

1. chromosomes decondense and are no longer visible
2. new nuclear envelope forms

Question 10

What is binary fission

Answer 10

The method of cell division used by prokaryotes involving replication of the circular DNA and plasmids followed by cytoplasmic division

Question 11

Describe the process of binary fission.

Answer 11

1. DNA loops replicate and attach to the cell membrane
2. plasmids replicate
3. cell elongates
4. DNA loops separate
5. cell membrane contracts (pinching inwards) which forms the septum
6. cytoplasm divides

both loop of DNA in point 1 stay attatched to the cell membrane

Question 12

What is the result of binary fission?

Answer 12

two identical progeny cells with 1 DNA loop each and various amount of plasmids

Question 13

How do you find how many times a bacteria?

given the time frame, frequency and that it begins with 1 bacteria

Answer 13

1. put the time frame in minutes
2. divide the time frame by the fequency
3. then put that answer as a power of 2

Question 14

What happens in cytokinesis?

Answer 14

1. the cytoplasm divides
2. parent cells become two genetically identical daughter cells

Question 15

What factors increase the rate of bacteria growth (and why)?

Answer 15

Increased:

1. levels of glucose (increases respiration)
2. concentration of oxygen (increases respiration)
3. temperature (increases enzyme activity)
4. concentration of phospate (increases ATP and therefore energy)
5. concentration of nucleotides (increases DNA synthesis)