Week 4_Cell division_binary fission

Question 1

cell division is a key element of life that’s important for…

Answer 1

(1) reproduction

(2) growth

(3) wound healing

(4) replacing cells that die or are lost

Question 2

cell division requires 3 things:

Answer 2

1) replication of genetic material

2) accurate segregation of genetic material

3) division of cytoplasm b/n 2 cells

Question 3

cell division needs to be ___ and ___ to environmental conditions

Answer 3

controlled

responsive

Question 4

contrast prokaryote and eukaryote:
- size
- nucleus?
- membrane-bound organelles?

Answer 4

prokaryotes:
- small cell size
- nucleus absent
- membrane-bound organelles absent

eukaryotes:
- large cell size
- nucleus present
- membrane-bound organelles present

Question 5

what are examples of prokaryotes?

Answer 5

bacteria

Question 6

what are examples of eukaryotes?

Answer 6

plants, animals, protists, and fungi

Question 7

bacteria divide by ___

Answer 7

binary fission

Question 8

what is binary fission?

Answer 8

a form of asexual reproduction

one cell divides into 2 cells (clones)

Question 9

binary fission requires…

Answer 9

duplication and segregation of genetic material

and

division of the cytoplasm

Question 10

where is genetic material contained in a bacteria?

Answer 10

nucleoid –> non-membrane bound region of compacted DNA (also contains proteins)

Question 11

do prokaryotes usually have more or less genetic material than eukaryotes?

usually a single circular chromosomes has around ___ base pairs

Answer 11

less

~4 million bp

Question 12

describe size of prokaryotic “chromosomes”

Answer 12

usually smaller than eukaryotic chromosomes

however, prokaryotic “chromosomes” are still large

Question 13

how long is an E. coli chromosome?

how long is an E. coli cell?

chromosome must be compacted to take up at least ___ times less space in the cell

Answer 13

1,400 micrometers in length

~2 micrometer

1000 times

Question 14

bacterial chromosome compaction:

the 1st level of DNA compaction: DNA is looped around ___ to form ___

further compacted into ___

Answer 14

SMC proteins to form loop domains

supercoils

Question 15

describe the process of binary fission:

Answer 15

1) cell increases in size

2) circular bacterial chromosome is replicated

3) replication begins at the origin of replication and proceeds in both directions to the site of termination

4) new chromosomes separated and partitioned to opposite ends of the cell

Question 16

describe the process of septation (dividing the cell into 2)

Answer 16

5) FtsZ proteins form a ring around the middle of the cell called a septum

6) the septum begins to shrink and divide the cell

7) the septum divides the cell completely into 2 daughter cells