4- human genome

Question 1

what is your phenotype?

Answer 1

what you look like

Question 2

what is your genotype?

Answer 2

your genetics

Question 3

what is precision medicine?

Answer 3

when you look at someone’s specific genetic make-up to see what medicine will be effect for people (different treatment for different genetic make-up)

Question 4

describe DNA structure

Answer 4

-sugarphosphate bcakbone
-antiparallel strands
-base pairs A&T and G&C
-from 5’ to 3’ end
-complex molecule

Question 5

what do chromosomes look like within nucleus?

Answer 5

it looks like a ball of string, stained fluorescent

Question 6

how do you recognise chromosomes?

Answer 6

by size and where stripe is

Question 7

how many bases in human genome?

Answer 7

3 billion bases

Question 8

how many genes in human genome?

Answer 8

20 000-30 000

Question 9

how many copies of gene per cell?

Answer 9

2 copies

Question 10

what % of bases encode for genes?

Answer 10

2%

Question 10

what stage in cell cycle is replication?

Answer 10

S phase

Question 10

what is short description of mitosis?

Answer 10

one diploid parent cell becomes 4 haploid daughter cells (meiosis I and meiosis II) with crossing over, chiasmata

Question 10

what is promoter sequence?

Answer 10

part of gene before bit to be encoded, it has TATA box and is bit where transcription factor binds

Question 10

what is pre mRNA?

Answer 10

DNA is transribed to pre mRNA ( has intorns & exons) and then pre mRNA spliced to mRNA

Question 10

what does DNA strands associate with?

Answer 10

proteins (including histones)

Question 11

what can be caused by chemical crosslinking?

Answer 11

xeroderma pigmentosa

Question 12

what are examples of DNA damage?

Answer 12

-DNA strand breaks
-UV or chemical crosslinking
-mismatched base

Question 13

what is a result of mismatched base?

Answer 13

hereditary colorectal cancer

Question 14

what is amount of protein produced determined by?

Answer 14

=Rate of transcription (manufacture of Pre-mRNA)
=Rate of splicing to mRNA
=Half life of mRNA
=Rate of processing of polypeptide

Question 15

what are sequence changes that occur in DNA between genes?

Answer 15

• Single Nucleotide polymorphisms (SNPs)
• Larger deletions or duplications

Question 16

what are sequence variations within genes?

Answer 16

• Changes in the promotor sequence
• Changes in the exon sequence
• Ones that change an amino acid
• Sequence changes that do not

Question 17

what are polymorphisms?

Answer 17

Any variation in the human genome that has a population frequency of greater than 1%

or

Any variation in the human genome that does not cause a disease in its own right. It may however, predispose to a common disease
(changes in genome that are just like the differences between us - not disease causing)

Question 18

what lead to variation in meiosis?

Answer 18

the random crossing over of genes that mean everyone has new genetic variants that their parents don’t

Question 19

what is symptomatic testing?

Answer 19

testing for disease on person who has symptoms

Question 20

what is pre-symptomatic pregnancy?

Answer 20

patient has relative with known disease and wants to know if they have it

Question 21

what does recombination in meiosis ensure?

Answer 21

that genetic variants on same chromosome segregate independently (irrespective of maternal/paternal origin)