Producing New Cells

Question 1

What does the nucleus contain?

Answer 1

contains all genetic information for the cell to function and is in control of cell division

Question 2

What is genetic information stored in?

Answer 2

Long threads of DNA called chromosomes

Question 3

What is the center of a chromosome called?

Answer 3

centromere

Question 4

What is the name given to the chart presenting someones chromosome complement?

Answer 4

karyotype

Question 5

What is the human chromosome complement ?

Answer 5

46

Question 6

How many sets of chromosomes does a diploid individual have ? (human)

Answer 6

2 sets of chromosomes= 46

Question 7

How many sets of chromosomes does a haploid individual have? (human)

Answer 7

1 set of chromosomes = 23

Question 8

Name 2 haploid cells in humans ?

Answer 8

sperm and egg

Question 9

Sperm and egg produce a diploid zygote, how from then onward are more cell produced?

Answer 9

By mitosis

Question 10

What happens to the human chromosome complement of a diploid zygote after mitosis?

Answer 10

remains the same

still is diploid, containing 46 chromosomes

Question 11

Describe what happens at stage 1 of mitosis and what it is called?

Answer 11

During this stage the chromosomes copy themselves to form 2 chromatids. The chromosomes are difficult to see in the nucleus.
This is called interphase.

Question 12

Describe what happens at stage 2 of mitosis and what it is called?

Answer 12

The chromosomes become easier to see as they shorten and thicken. The 2 chromatids are joined at a point called the centromere.
This called prophase.

Question 13

Describe what happens at stage 3 of mitosis and what it is called?

Answer 13

Towards the end of this phase the membrane, surrounding the nucleus disintegrates. Spindle fibres form and become attached to the chromosomes (each now 2 chromatids) at the centromeres. The chromosomes are arranged at the equator of the cell.
This is called metaphase.

Question 14

Describe what happens at stage 4 of mitosis and what it is called?

Answer 14

During this phase the chromatids are pulled apart to opposite ends (poles) of the cell.
This is called anaphase.

Question 15

Describe what happens at stage 5 of mitosis and what it is called?

Answer 15

A nuclear membrane forms round each set of separated chromatids which are now called chromosomes and the cytoplasm and membrane can divide.
This is called telophase.

Question 16

Describe what happens at stage 6 of mitosis and what it is called?

Answer 16

Two identical daughter cells have been formed.

This is called cytokinesis.

Question 17

What have humans use cell division for ?(2)

Answer 17

industry and medicine

Question 18

What is the process of growing cells artificially in a medium called?

Answer 18

Cell Culture

Question 19

What does cell production by cell culture require?(3)

Answer 19

aseptic techniques
an appropriate medium
other factors to be controlled

Question 20

The air around us is full of bacteria and fungal spores that could contaminate cell cultures. To stop airborne unwanted microbes getting into our cell cultures what could we use?

Answer 20

aseptic techniques.

Question 21

What are the 9 aseptic techniques?

Answer 21

Close windows and doors to reduce droughts and prevent sudden movements which might disturb the air.
Disinfect the benchtop.
Only start when all apparatus and materials are within reach.
Complete all activities as quickly as possible but without any hurry.
Vessels are open for the minimum amount of time.
Use a Bunsen burner flame to create a convection current.
Flame the neck of test tubes and McCartney bottles.
Keep the lids on petri dishes and bottles to limit exposure to the air.
Sterilise all items before and after contact with micro-organisms.

Question 22

What conditions are monitored and controlled in a fermenter?

Answer 22

food supply
air supply -to control oxygen concentration
pH- the correct level of acidity
Temperature- optimum for growth normally between 20’c and 40’c
agitation - amount of stirring
aseptic techniques