Mitosis

Question 1

Interphase

Answer 1

G1 -cells undergoes rapid growth
S- centrosomes divide
G2- ribosomes and mitochondria are evenly distributed

Question 2

Prophase

Answer 2

• chromosomes start to condense
• nuclear membrane disintegrates
• spindle forms between centrioles
• centrioles migrate to opposite poles

Question 3

Metaphase

Answer 3

• chromosomes line up along equator

- chromosomes attach to spindly fibres by centromeres

Question 4

Anaphase

Answer 4

• spindle fibers shorten
• chromatids pulled to opposite poles
• chromosomes sperate

Question 5

Telophase

Answer 5

• chromosomes form groups at each pole
• chromosomes uncoil and become less visible
• nuclear envelope forms around each group of chromosomes

Question 6

Mitosis

Answer 6

DNA replicates

Question 7

difference between mitosis and meiosis

Answer 7

MITOSIS

• everywhere throughout cell (somatic cells)
• cell division
• 2 diploid, identical daughter cells produced
• form of asexual reproduction
• 46 chromosomes
• 1 cycle

MEOISIS

• sexual reproduction ( only in sex cells)
• 23 chromosomes
• 4 haploid, unique daughter cells produced
• 2 cycles

Question 8

what is the control checkpoint

Answer 8

-step of cell cycle where cycle is checked for repairs or damage of DNA before preceding to mitosis

Question 9

steps of the cell cycle

Answer 9

INTERPHASE: G1, S, G2
Checkpoint
MITOSIS
CYTOKENISIS

Question 10

what are CYCLINS

Answer 10

a family of proteins that control the progression of cells through the cell cycle

Question 11

process of CYCLINS

Answer 11

1. Cells cannot progress to the next stage of the cell cycle unless a specific cyclin reads its threshold
2. cyclins bind to enzymes called cylin-depedent kinases =
3. these kinases then become active and attach phosphate groups of other proteins in the cell
4. the attachment of phosphate triggers the other proteins to become active and carry out tasks (specific to one of the phases of the cell cycle)

Question 12

what are kinases

Answer 12

family-related enzymes

Question 13

correlation…

Answer 13

does not mean causation

Question 14

types of tumor formations

Answer 14

1. Mutagens
2. Oncogenes
3. Metastasis

Question 15

what are mutagens

Answer 15

carcinogenic chemicals (cancer causing), high energy radiation 
e.g X-rays of lungs

Question 16

what are oncogenes

Answer 16

genes that have mutated that can cause cancer

Question 17

what is metastasis

Answer 17

movement of cells from a primary tumor to set up a secondary tumor (CANCER SPREADS THROUGHOUT BODY)

Question 18

what are the features of a cancer cell (tumor)

Answer 18

• cancer cells do not differentiate into a specialist cell type
• a cancer cell is parasitic, taking nutrients from a surrounding cells by forming large numbers of blood vessels to supply it
• a cancer cell undergoes uncontrolled division

Question 19

what are risk factors

Answer 19

anything that increase a change of developing a disease
-are correlational but not casual
e.g international travel= risk factor for malaria
cause= parasite in mosquitos
- smoking is a major risk for cancer

Question 20

What does epidemiology mean

Answer 20

the study of people

Question 21

difference between reliability and validity

Answer 21

RELIABILITY- the consistency of findings

VALIDITY- measuring what you set out to measure

Question 22

what is lung cancer

Answer 22

• biggest cause for cancer-related deaths
• 90% of cases caused by smoking
• mos cases due to uncontrolled growth of epithelial cells living in the airway (cancer arising from the cells are called carcinomas)

Question 23

symptoms of lung cancer

Answer 23

• shortness of breath
• coughing
• loss of weight
• nausea

Question 24

timeline of the progression the smoking is the causation for lung cancer

Answer 24

1. RICHARD DOLL AND AUSTIN BRADFORD (1950)
   investigate 17000 men and women in London
   find: risk of developing lung cancer increases in proportion to the amount smoked
2. BRITISH MALE DOCTORS INVESTIGATION (1950-2001)
   - study of British male doctors health and smoking habits

found:

• lifelong smokers died, on average, 10 years earlier than non smokers
• the earlier smokers stopped smoking ,the more chance they have of avoiding reduced life expectancy .