Lesson 2- Mitosis (Cellular growth and reproduction)

Question 1

What is mitosis

Answer 1

• Cellular reproduction and growth.
• Mitosis is how the cells divide.
• If the body is healthy cells will grow and reproduce healthy cells to replace old damaged cells. As long as conditions are favorable’s cell will grow and reproduce.
• When the nucleus divides each daughter cell ends up with exactly the same genetic information as the original mother cell in the original fertilized egg from which it came from.
• Mitosis serves all other functions of cell divisions: development of an individual, growth of tissues and organs after birth, replace cells that die and repair damaged tissue.
• Mitosis happens more in babies which is why they look so different from one week to the next.

Question 2

How long does it take for the body to complete stages of mitosis

Answer 2

Depending on the type of tissue it takes from five minutes to several hours to complete, but typically lasts about two hours. Stomach and skin cells, for example, divide rapidly. Bone and cartilage cells grow slowly.

Question 3

Define interphase

Answer 3

• Not really a part of cell division
• It is a resting stage between cell division
• Much of the cells lifespan is spent in the stage
• It is a time of growth and maturation
• Chromosomes spread through the nucleus
• Nucleus is still surrounded by nuclear membrane
• Near the end of the interphase, centrioles start to move a part to begin mitosis

Question 4

Name the four stages of mitosis

Answer 4

Use acronym PMAT to remember four stages.

1. Prophase
2. Metaphase
3. Anaphase
4. Telophase

Question 5

Describe prophase stage of mitosis

Answer 5

• Centrioles begin to move to opposite sides of the nucleus
• Chromosomes become visible- they shorten, thicken and double into pairs and become known as chromatids
• Nuclear membrane disappears
• Spindle fibres begin to form and attach themselves to the centrioles

Question 6

Describe the metaphase stage of mitosis

Answer 6

• Chromatids become aligned in the middle of the spindle fibres [become more organized]
• The genetically doubled pairs of chromatids split evenly and begin to move a part on the spindle fibres

Question 7

Describe the anaphase stage of mitosis

Answer 7

• Chromatids seem to repel each other and move to opposite ends of the spindle fibre
• The cell starts to constrict at the middle
• Anaphase is over when chromosomes movements end

Question 8

Describe the telophase stage of mitosis

Answer 8

• Chromosomes lengthen into fine networks
• Spindle fibre disappears
• Two nuclei are formed and a nuclear membrane around each nucleus is also formed
• The cell pinches further inward and divides into two daughter cells
• Each cell is genetically equal
• Both new cells then enter a new interphase

Question 9

What is the difference between mitosis and meiosis

Answer 9

Mitosis – refer to previous card info

meiosis - is a type of reproduction in which the number of chromosomes are reduced by half through the separation of chromosomes, producing two haploid cells [4 cells] as opposed to only two cells in mitosis. The cells have to go through the process twice in order to have correct chroma zonal information I.e Egg and sperm.
With meiosis we need X and Y to reproduce in mitosis we don’t

Question 10

Define homeostasis

Answer 10

The word homeostasis describes the body‘s ability to maintain relatively stable internal conditions even though the outside world is continuously changing. It indicates a dynamic state of equilibrium. In general the body is in homeostasis when it’s needs are being adequately met and it is functioning smoothly.