Mitosis and cancer Flashcards Preview

Gd 10 - Life Sciences 2017 > Mitosis and cancer > Flashcards

Flashcards in Mitosis and cancer Deck (37):
0

One cells cell cycle starts... and ends..

-Starts when the cell forms

-Ends when as a mature cell it divides into two daughter cells

1

Substance between cell membrane and nucleus containing organelles

Cytoplasm

2

Two main phases of the cell cycle

Interphase

Mitosis

3

Phase in which DNA is replicated

Interphase

4

Chromosomes of DNA that has replicated consist of...

-Two sister chromatids

-Joined by a centromere

5

Two sister chromatids constitute one...

Chromosome

6

Features of a cell in interphase prior to mitosis

1. Cell growth

2. DNA replication

3. More growth and preparation for cell division

7

A small cell versus a large cell's surface to volume ratio

-Small cell: large surface area to volume ratio

-Large cell: small surface area to volume ratio

8

A small surface area to volume ration forces the cell to...

Divide into two daughter cells

9

Time for typical mitosis phase to take place

1-2 hours

10

After cell division, the fate of the daughter cells

-One often grows and divides again

-The other usually changes to form a specialized cell (tissue)

11

Why cells divide

Growth

Repair

Reproduction (asexual)

12

Region in plants where cell division occurs

-Apical meristem (tips of roots, shoots and buds)

-Lateral meristem (under bark)

13

Division of the cytoplasm

Cytokinesis

14

Mitosis

Division of the nucleus

15

Early prophase

-DNA becomes visible as chromosomes

-Centrosomes made of two centrioles moving towards cell poles

-Microtubule structures start to form spindle

-Nucleolus disappears

16

Late prophase / prometaphase

-Nuclear membrane disintegrates

-Microtubules attach themselves to the chromosomes

-Spindle apparatus formed

-Chromosomes start to move towards equator

17

Metaphase

-Nuclear membrane disintegrated

-Centrosomes pull on chromosomes using spindle (tug of war)

-Chromosomes lined up along equator

18

Anaphase

-Centromeres cleave

-Sister chromosomes split to form daughter chromosomes

-Daughter chromosomes pulled by microtubules towards opposite spindle poles

-Polar microtubules elongate cell

19

Telophase

-Daughter chromosomes reach opposite poles

-New nuclear membrane forms around each set

-Nucleolus reforms

(Not part of mitosis but at the same time cytokinesis occurs)

20

Mode of cytokinesis in animal cells

Cleavage furrow

21

Mode of cytokinesis in plant cells

Cell plate formed separating daughter nuclei

22

Cancer

A broad group of diseases involving unregulated cell growth

23

Cancer cells appear different to normal cells

Little cytoplasm

Multiple nuclei

Coarse chromatin

24

Different types of cancer

Carcinoma - epithelial tissue

Sarcoma - connective tissue

Leukemia - blood/bone marrow

Blastoma - other stem/precurser cells

25

Causes of cancer

Genetic (5-10%)

Tobacco (25-30%)

Diet and obesity (30-35%)

Infections (15-20%)

Radiation (10%)

Stress, lack of exercise and pollution

26

Types of tumor

Benign

Malignant

27

Benign tumors

Stay at one site

Don't spread

28

Malignant tumors

Cancer cells spread

Other organs affected

29

Cancer metastasis

Cancer cells affect organs and tissues different from cancer origin

30

Cancer treatments

Surgery

Chemotherapy

Radiotherapy

Complementary therapy

31

Cancer surgery

Remove cancer cells with scalpel or laser

32

Chemotherapy

Chemicals that kill cancer cells

Chemicals that stop DNA from making new cells

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Radiotherapy

Using radiation to target cancer cells

34

Prevent cancer by avoiding

Tobacco

Obesity

Insufficient diet

Physical inactivity

Alcohol

STI's

Air pollution

35

Complementary cancer therapy

Alternative treatments not affecting each other or affecting prescribed medical treatment

Usually aim to treat or relieve symptoms

E.g. Traditional medicines

E.g. Prayer/ positive thinking techniques

36

Traditional medicines used to treat cancer

Cancer bush tea

African wild potato

Both believed to strengthen immune system