Differentiation

Question 1

characteristics of stem cells

Answer 1

1) unspecialised - differentiate
2) self-renewal when cells specialise to replace

Question 2

what 2 things cause differentiation

Answer 2

1) external signals - chemical signals from cells
2) internal signals - gene expression

Question 3

stem cell potency levels

Answer 3

1. totipotent - single cell makes entire individual (all cells), can self renew (no limit)
2. pluripotent - embryonic cells, can form 3 germ layers (endoderm, ectoderm, mesoderm
   3.multipotent - adult stem cells, multiple but limited cells -> limited ability to divide, proginator cells
3. unipotent - slef-renew, one cell type possible, muscle and epithelial stem cells

Question 4

what is the final cell type of stem cells

Answer 4

terminally differentiated = mature blood cells

Question 5

how could stem cells be used for cloning

Answer 5

• take DNA from a mature non-stem cell
• place into a totipotent cell and allow to differentiate into entire organism

Question 6

what is cancer

Answer 6

• a mass of cells capable of uncontorlled growth
• lack cell cycle control
• can spread

Question 7

types of cancer and what they affect

Answer 7

1. carcinoma = epithelial cells (90% cancer)
2. Sarcoma = supporting tissues e.g. bone tissue
3. Lymphoma and leukemia = blood cells and lympathic cells

Question 8

causes of cancer

Answer 8

1) activation of oncogenes -> proto-oncogenes are genes that allow cell division, if damaged, can form oncogenes that cause cancers
2) loss of antioncogenes - regulate cell cycle and repair DNA, loss = survival of cancer cells
3) spontaneous mutation
4) genetics
5) oncoviruses - insertion of oncogenic genes via virus
6) carcinogens - cause DNA damage

Question 9

process of carcinogenesis

Answer 9

1. initiation = event changes normal cell to precancerous cell (sensitive)
2. promotion = repeated exposure to cancer causing agents
3. tumor progression = loss of normal ploriferation control

Question 10

benign vs malignant tumors

Answer 10

benign - confined to local area, rarely dangerous

malignant - invade surrounding tissues, bloodstream, travel through body

Question 11

invasion vs metastasis

Answer 11

invasion = migration of cancer cells into adjacent tissues
metastasis = ability of cancer cells into blood and lymphatic system

Question 12

where does blood orginiate

Answer 12

mesoderm

Question 13

how much blood do humans have

Answer 13

5-7L

Question 14

how much of blood is ells and plasma

Answer 14

cells = 40%
plasma = 60%

Question 15

what is plasma vs serum

Answer 15

plasma = liquid component of non-clotted blood
serum = liquid component of blood after clotting

Question 16

types of blood cells

Answer 16

1. red = O2
2. platelates = clotting
3. white = immune protection

Question 17

funtions of blood

Answer 17

1) transport
2) comunication - hormones
3) regulation - homesostasis
4) protection - wound healing, infections (clotting)

Question 18

how can blood regulate temp

Answer 18

• vasodilation and constriction

Question 19

how does blood clot

Answer 19

• platelets in blood connect to broken connective tissue and release clotting factors
• clotting factors = secondary haemosasis -> strengthen clot

Question 20

what cells have no nucleus

Answer 20

• RBC, platelets

Question 21

5 types of white blood cells

Answer 21

1) monocyte
2) lymphocyte
3) eosinophyls
4) neutrophils
5) basophils

Question 22

what cells do have a nucleus

Answer 22

all white blood cells

Question 23

what is the abundance of each blood cells

Answer 23

neutrophils = most
lymphocutes
monocytes
eosinophils
basophils

Question 24

what is blood stained with

Answer 24

blue = haematoxylin - neg molecules
red - eosin, pos molecules

Question 25

neutrophil charactteristics

Answer 25

- multi lobed nucleus (many) - phagocytotic - bacterial infections - clear/pale purple cytoplasm

Question 26

eosinophils

Answer 26

- red cytoplasm - bi-lobed nucleus - parasitic infections - allergy

Question 27

basophils

Answer 27

- bi lobed - immune/infalmmatory/allergy - blue - granules very aparent

Question 28

lymphocytes

Answer 28

- round nucleus - no granules - adaptive immunity - no cytoplasm - viral infections

Question 29

monocytes

Answer 29

- large - weird shaped nucleus - pale cytoplasm - form macrophages in tissues to fight microbes

Question 30

how do white blood cells form

Answer 30

haematopoiesis -> progenitor cells -> terminally differentiated blood cells