3.8.2 Gene expression and cancer Flashcards Preview

SHHS - Science - NEW AQA A-Level Biology (Year 2) > 3.8.2 Gene expression and cancer > Flashcards

Flashcards in 3.8.2 Gene expression and cancer Deck (123)
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1

Totipotent stem cells are able to differentiate into..

any type of body cell

2

multicellular organisms are made up from...

many different types of specialised cells

3

specialised cells originated from..

stem cells

4

unspecialised cells that can develop into other cell types are called

stem cells

5

Two main sources of stem cells can be found..

in the embryo, adult tissues

6

these types of stem cells are only present in mammals in the first few divisions of the embryo

totipotent (very early embryo)

7

these types of stem cells are still found in the embryo but have lost their ability to develop into differentiate into placental cells

pluripotent

8

adult stem cells can be one of two types

1. multipotent stem cells
2. unipotent stem cells

9

these types of stem cells can differentiate into a limited number of stem cells e.g. bone marrow cells can form RBC and WBC

multipotent stem cells

10

These types of stem cells can only differentiate into ONE type of cell

unipotent

11

Stem cells specialise because...

different genes are expressed (turned off and on)

12

All cells contain the same DNA - true or false?

true

13

Stem cells all contain the same genes - true or false?

true

14

Molecules which regulate the expression of genes are called..

transcription factors

15

Where do transcription factors bind to regulate gene expression?

upstream of the gene (promoter region)

16

What do transcription factors do to regulate gene expression?

encourage binding of RNA polymerase (turn on genes) or prevent RNA polymerase binding (turn off genes)

17

Where are transcription factors found?

nucleus

18

When a cell receives a signal to express a gene what does the transcription factor do?

moves from the cytoplasm to the nucleus

19

Specialised cells all look different - why?

they all express different genes and thus proteins - this determines the cells overall structure

20

Which stem cell can red blood cells originate from?

bone marrow stem cells

21

Transcription is when

DNA is copied into mRNA

22

Translation is when

mRNA is translated into a sequence of amino acids

23

what are cardiomyocytes?

heart cells

24

what can stem cells be used for?

treat diseases e.g. paralysis - replace damaged cells/tissues

25

benefits of using stem cells in medicine?

save life and improve quality of life for many people

26

iPS cells stands for?

induced pluripotent stem cells

27

What are iPS cells?

created in the lab - reprogramming adult stem cells to become pluripotent

28

What are the limitations with adult stem cells?

limited differentiation capacity - they are mulitpotent

29

Where do we source embryonic stem cells from?

embryos created in the lab from IVF

30

Embryonic stem cells are classified as one of twp types

1. totipotent (very early embryo)
2. pluripotent (early embryo)