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Biology Revision Year 2 > Control of Gene Expression > Flashcards

Flashcards in Control of Gene Expression Deck (62)
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1

define mutation

a change to the nucleotide sequence of DNA

2

what does a Mutogenic Agent do?

increases the rate of mutation

3

What is a Base Analogue?

a chemical that can substitute for a normal nucleotide base ----> substition mutation

4

what does radiation cause?

change to the structur of DNA eg) UV

5

describe substitution

one base swapped for another one

6

describe addition, and what it causes

one base added this causes frame shift

7

describe deletion

one base is removed

8

decribe inversion and what it can cause

sequence of bases are reversed, can cause no change (degenerate) ,change a few, doesn’t cause frame shift

9

describe duplication

one or more bases are repeated

10

describe translocation

DNA is moved from one part of a genome to another part of a genome

11

what could be the impact of the alteration of one AA?

changes primary structure, changing H bonds, changing tertiary structure (could have negligable change)

12

what does change to many AA cause?

frame shift= change to primary/H bonds ---> tertiary

13

describe stem cells

capable of diffferentiating into specialised cells, can divide for the organisms lifetime (no apoptosis)

14

what is a totipotent stem cell?

can differentiate into any specialised cell, found in early mammalian embryos

15

describe a pluripotent cell

can differentiate into many types of cells, but cannot make placental cells

16

describe a multipotent stem cell

can differentiate into a few types of specialised cells

17

describe a unipotent stem cell

stem cells that can differentiate into one type of cell

18

what happens when a cell becomes specialised?

conditions inside the cell control which genes are expressed (eg) transcription factors) cells become irreversibly specialised

19

How can we obtain induced pluripotent stem cells (iPS)

use a modified virus as a vector, virus inserts transcription factors from pluripotent ----> unipotent, transcription factors are expressed

20

how can we obtain embryonic stem cells?

IVF embryos, pluripotent stem cells are removed after a few days, pluripotent cells can differentiate into all types of body cell

21

how can we obtain Adult Stem Cells?

taken by consenting adults in an operation (eg) bone marrow) Adult stem cells are multipotent

22

how can bone marrow be used in medicine?

contain multipotent stem cells, can differentiate into WBCs and RBCs, donor bone marrow can be used to treat leukemia

23

how can stem cell grown organs be used in medicine?

no donor required, use iPS cells, no rejection

24

what are the advantages of stem cells in medicine?

improve quality of life, prevent suffering, save lives

25

what are the disadvantages of stem cells in medicine? (how can some of these be combatted)

embryos could develop into a foetus, fertalised ---> right to life ( use an unfertalised egg that has been triggered to multiply, or develop iPS cells)

26

define transcription factor

proteins that control the rate of transcription by switching genes on and off

27

define promotor region

short sequence of DNA at the start of the gene that the ribosome attaches to

28

decribe the process of a transcription factor

TF moves from the cytoplasm to the nucleus, binds to the promotor region, activate/ repress transcription by helping/ preventing RNA ploymerase binding to DNA

29

describe using the example of oestrogen how transcription factors can be controlled

steriod hormone, binds to receptor, foring oestrogen - oestrogen receptor complex, alters shape to make transcription factor

30

define cancer

uncontrolled cell division resulting in a tumour