Mitosis/Bacterial & Viral RP

Question 1

What are chromosomes joined in the middle by?

Answer 1

A centromere.

Question 2

What is a sister chromatid?

Answer 2

Two strands on the same chromosome.

Question 3

What are centrioles?

Answer 3

Proteins which move to opposite ends of the cell and produce spindle fibres.

Question 4

What don’t plants have regarding prophase?

Answer 4

Centrioles or spindle fibres.

Question 5

What is binary fission?

Answer 5

A form of mitosis, the cell replicates its genetic material before splitting into 2 DC.

Question 6

What do we grow colonies of bacteria on to observe BF?

Answer 6

Agar gel plates or in nutrient broth.

Question 7

Why do we grow cultures of microorganisms?

Answer 7

To investigate the action of disinfectants and antibiotics.

Question 8

What’s the difference between circular DNA and plasmids?

Answer 8

ODNA replicates once but plasmids can do many times.

Question 9

How does a circular DNA replicate?

Answer 9

Cell englarges, circular moves to opposite poles of the cell & attach to the cell membrane.
Cytoplasm begins to divide and a new cell wall forms.
CP splits, two DC.

Question 10

What are viruses?

Answer 10

Nucleic acids surrounded by protein.

Question 11

What are 4 properties of viruses?

Answer 11

-Can only reproduce inside host cells.
-No cell surface membrane, RS and CP.
-Protein coat called a capsid, with attachment proteins sticking out.
-Attachment proteins bind to the host cell.

Question 12

Why do different viruses require different receptor proteins?

Answer 12

They have different attachment proteins.

Question 13

How do viruses replicate?

Answer 13

-Inject their DNA into a host cell.
-Incorporate their DNA into the host cell’s DNA.
-They then use the host cell’s reproductive DNA code to replicate nucleic acids, enzymes + structural proteins which are assembled into new viruses.

Question 14

describe the events of prophase

Answer 14

chromosomes condense to become visible and fat
centrioles split and move to opposite ends of the cell, spanning spindle fibres from pole to pole to produce the spindle apparatus
the nuclear envelope disintegrates and chromosomes are freed into the cytoplasm

Question 15

describe the events that occur in metaphase

Answer 15

spindle fibres attach to the chromosomes at their centromeres and chromosomes are pulled along the apparatus to line up along the equator of the cell

Question 16

describe the events that occur during anaphase

Answer 16

centromeres divide into two and spindle fibres pull individual chromatids apart to opposite poles of the cell

Question 17

describe the events in telophase

Answer 17

chromatids reach opposite poles of the cell
the nuclear envelope reforms around the chromosomes
the cell prepares to split its cytoplasm and contents

Question 18

describe what happens in cytokinesis

Answer 18

the cytoplasm and cell membrane separate to form two identical daughter cells

Question 19

describe the events in binary fission

Answer 19

circular DNA replicates and both copies attach to the cell membrane
the plasmids also replicate
cell membrane begins to grow between the two DNA molecules and pinches inward, dividing the cytoplasm into two
a new cell forms between the two molecules, dividing the original into two identical daughter cells, each with a singular copy of circular DNA

Question 20

describe the events that occur in viral replication

Answer 20

the virus attaches glycoproteins to the complimentary receptors on their host cells
they inject their DNA/RNA into the host cell
the host cell divides as normal and the virus is replicated

Question 21

describe the basic steps of the cell cycle

Answer 21

1- interphase occupies most of the cycle, the resting phase
2- nuclear division, either mitosis or meiosis
3- cytokinesis (cytoplasm divides)

Question 22

chromosome non dysjunction

Answer 22

chromatids fail to separate during anaphase so both go to one pole of the spindle

Question 23

human body cell chromosome number

Answer 23

46, diploid

Question 24

sex cell cs number humans

Answer 24

23, haploid

Question 25

consequence of offspring with uneven number of chromosomes

Answer 25

meiosis cannot occur so haploid cells are not produced

Question 26

start and end of meiosis

Answer 26

one diploid cell, two haploid n daughter cells after meiosis 1, 4 haploid n daughter cells after meiosis 2

Question 27

start and end of mitosis

Answer 27

two diploid daughter cells from one diploid body cells, genetically identical

Question 28

diploid

Answer 28

two complete set of chromosomes

Question 29

haploid

Answer 29

one complete set of chromosomes