Genome structure and chromosome abnormalities

Question 1

Adenine and Thymine make how many hydrogen bonds?

Answer 1

2

“A Tea for 2”

Question 2

Guanine and Cytosine make how many hydrogen bonds?

Answer 2

3

Question 3

Degenerate meaning

Answer 3

More than 1 codon per aa

Question 4

Mitochondria DNA comes from which parent?

Answer 4

Mother

Question 5

How do you avoid transmitting mitochondrial disease?

Answer 5

Want maternal egg but not cytoplasm

Nucleus removed from maternal egg and placed in donor empty egg with healthy mitochondria

Question 6

What is a chromatin?

Answer 6

Substance within chromosomes consisting of DNA and protein

Question 7

What are 2 different types of Chromatin

Answer 7

Euchromatin

Heterochromatin

Question 8

What is Euchromatin (chromatin)?

Answer 8

Prevalent in part of genome that is regularly used- where genes on

Less condensed
Can be transcribed

Question 9

What is heterochromatin (chromatin)?

Answer 9

Condensed form of chromatin made of tight loops- most abundant of genome where genes switched off

More condensed
Cannot be transcribed usually

Question 10

What is the P arm on chromosome?

Answer 10

Short arm of structure (of the X)

Question 11

What is the Q arm on chromosome?

Answer 11

Long arm of structure (of the X)

Question 12

Pathogenic variant

Answer 12

Affect on genome so no longer perform its function

Question 13

Genetic variant

Answer 13

Not going to have any impact on function of genome

Question 14

How can changes in DNA cause no effect?

Answer 14

Synonymous aa change (codes for same aa)

In non functional regions of genome

Question 15

How many chromosomes in gametes?

Answer 15

23 chromosomes

Question 16

How many chromosomes in somatic cells?

Answer 16

46 chromosomes

Question 17

When does variation occur in meiosis?

Answer 17

During crossing over
Independent assortment
“Errors” in replication- mutations- good for evolution or bad

Question 18

What do miss match repair enzymes do?

Answer 18

Look for missmatches and remove incorrect base and put in correct base

Question 19

When does crossing over occur in meiosis?

Answer 19

Prophase 1

Question 20

Where does crossing over occur?

Answer 20

At chiasma

Question 21

When does independent assortment occur?

Answer 21

During anaphase 1

Question 22

Nullisomy

Answer 22

caused by error at meiosis, causing 2 of gametes to have no chromosomes and other 2 to have double

Question 23

Monosomic zygote

Answer 23

Only one copy of chromosome after fertilisation

Question 24

Disomic gametes

Answer 24

Gametes having double amount of chromosomes

Question 25

What is trisomic zygote? | What causes it?

Answer 25

3 copies of a chromosome | If have disomic gametes

Question 26

Down syndrome is trisomy what?

Answer 26

21

Question 27

What is turner syndrome?

Answer 27

One copy of X chromosome

Question 28

Aneupolidy

Answer 28

Loss or gain of one or more chromosome

Question 29

Monosomy

Answer 29

Loss of a single chromosome

Question 30

Trisomy/tetrasomy

Answer 30

Gain of one or two homologous chromosomes

Question 31

Polyploidy

Answer 31

Have more than 2 sets of chromosomes

Question 32

Hydatidoform mole

Answer 32

growth of an abnormal fertilized egg or an overgrowth of tissue from the placenta.

Question 33

What is trisomy 21?

Answer 33

Downs syndrome

Question 34

What is trisomy 13

Answer 34

Patau syndrome

Question 35

What is Trisomy 18

Answer 35

Edwards syndrome

Question 36

Trisomy 13 (patau syndrome) symptoms

Answer 36

``` Cleft lip + palette Too many fingers Brain malformation Small eyes Reduced distance between eyes Clenched hands with outer fingers over lapping inner Reduced muscle tone ```

Question 37

Trisomy 18

Answer 37

William syndrome

Question 38

DiGeorge Syndrome symptoms

Answer 38

Heart problems Speech + hearing problems Learning + behaviour problems Hormone problems

Question 39

DiGeorge syndrome cause

Answer 39

Deletion of chromosome 22

Question 40

Aneuploidy risk

Answer 40

Maternal serum proteins, maternal age, fetal nuchal fold translucency