Survival guide

Question 1

Leading strand replication

Answer 1

Polymerase

Question 2

RNA

Answer 2

ribose, uracil

Question 3

What does the DNA helix wrap around?

Answer 3

Positive histone octomer

Question 4

Lagging strand replication

Answer 4

Ligase and Ozaki fragmments

Question 5

1 rosette

Answer 5

6 loops

Question 6

1 coil

Answer 6

30 rosettes

Question 7

1 sister chromatid

Answer 7

10 coils

Question 8

Chromosome

Answer 8

2 chromatids

Question 9

Prophase

Answer 9

Chromosomes condense and form part of the mitotic spindle

Question 10

Metaphase

Answer 10

Chromosomes line up in the centre of the dividing cell. Microtubules attach to each chromosome centromere via the kineticore.

Question 11

Anaphase

Answer 11

The duplicated chromosomes are separated by contraction of the microtubules.

Question 12

Telophase

Answer 12

The chromosomes reach the poles of the cell, and the two cells separate (Cytokinesis).
The chromosomes decondense and form part of the nucleus once more.

Question 13

When does recombination occur in meiosis?

Answer 13

Prophase in meiosis 1

Question 13

Recombination in meisosis

Answer 13

Homologous chromosomes pair and there is crossing over between the homologous chromatids.

Question 14

Meiosis 2

Answer 14

Second round of division to make 4 haploid daughter cells

Question 15

How many chromosomes in meiosis 1 cell

Answer 15

Double normal

Question 16

Acrocentric chromosome

Answer 16

Only satellite DNA on the p arm

Question 16

Which phase are chromosomes visualised in?

Answer 16

Metaphase

Question 17

Balanced chromosome complement

Answer 17

Normal amount of each chromosome

Question 18

Karyotype format

Answer 18

47 XY +21

Question 18

Most common cause of ansuploidy

Answer 18

Nondisjunction

Question 19

Translocation types

Answer 19

Robertsonian
Reciprocal

Question 19

Which arm is lost in Robertsonian translocations?

Answer 19

p

Question 20

22.q11.2

Answer 20

22 - chromosome
q - arm
1 - region
1 - band
2 - sub band

Question 21

FISH steps

Answer 21

Complementary DNA/RNA probe Denaturation: Nicks are created in the DNA Hybridisation: Nucleotides with a Fluorophore attached are incorporated into the strand

Question 22

What is FISH used for

Answer 22

Chromosomal abnormalities in cancer

Question 23

What do chromosomal microarray dots show?

Answer 23

Strong Patient DNA Binding - Duplication Normal Quantity of DNA Weak Patient DNA Binding - Deletion

Question 24

Is CMA or karyotyping higher resolution?

Answer 24

CMA

Question 25

X inactivation mechanism

Answer 25

Starts at the Xist gene on one of the two X chromsomes in a cell This expresses a large RNA molecule that coats the chromosome Condensation of the inactive chromosome into heterochromatin, supressing gene transcription

Question 26

Inactivation transforms the chromosome into a _____ body.

Answer 26

Barr

Question 27

When is the X inactivation pattern removed?

Answer 27

Germ cell formation

Question 28

Splicing turns…

Answer 28

pre mRNA to mRNA.

Question 29

Splicing

Answer 29

Small Nuclear Ribonucleoproteins (SNRPs) recognise specific RNA sequences (called Motifs) forming a spliceosome.

Question 30

SNRP examples

Answer 30

Splice Acceptor Splice Donor Lariat sequences

Question 31

What does the spliceosome contain?

Answer 31

small nuclear RNAs (U1 - U6)

Question 32

How is the Lariat loop formed?

Answer 32

Chemical reaction cleaves the 5' end of the intron from its upstream exon and attaches it to the branch point, forming a loop called a lariat

Question 33

tRNA structure (clockwise)

Answer 33

Acceptor stem T loop Anticodon loop D loop

Question 34

Ribosome sites

Answer 34

APE

Question 35

T loop function

Answer 35

Stabilizing the tertiary RNA structure by facilitating long-range interactions between regions

Question 36

D loop function

Answer 36

Recognition site for the enzyme aminoacyl-tRNA synthetase

Question 37

Acceptor stem function

Answer 37

Codes for amino acid sizes

Question 38

Stop codons

Answer 38

UGA UAG UAU

Question 39

Post translational modification examples

Answer 39

Folding Transport Side chains Peptide assosciation

Question 40

N-linked glycosylation

Answer 40

Attachment of an oligosaccharide to nitrogen affects folding and the quality control of proteins in the ER

Question 41

Types of damage

Answer 41

Endogenous Exogenous

Question 41

Loss of nucleotide excision repair: example

Answer 41

Xeroderma pigmentosa

Question 42

Loss of homologous recombination: example

Answer 42

BRCA1

Question 43

Mendel’s law of independent segregation

Answer 43

Recombination in meiosis 1

Question 44

Frameshift writing example

Answer 44

c.6delA p.Lys2Asnfs

Question 45

Stages if spermatogenesis

Answer 45

Spermatogonium Primary spermatocyte Secondary spermatocyte Spermatids

Question 46

Next generation sequencing

Answer 46

The sequences of the fragments are aligned against a reference genome sequence. If there is a variant in one copy of the genome, half the sequences will show the genetic variation compared to the reference sequence.

Question 47

X chromosome

Answer 47

153 million base pairs

Question 48

Y chromosome

Answer 48

58 million base pairs

Question 49

Multiple mitochondria

Answer 49

Multiple copies of the mitochondrial genome in each cell

Question 50

Activator protein binds to…

Answer 50

Enhancer region

Question 51

How is methylation passed on to daughter cells?

Answer 51

DNA methyltransferase 1 (DNTM1) at mitosis

Question 52

How does methylation prevent transcription?

Answer 52

Prevents binding of transcription factors and indirectly causes deacetylation of histones

Question 55

Yippee!