Gene & Chromosomal mutations

Question 1

genotypic variability

Answer 1

difference in the combination of alleles present in the genome.
- variations in the genetic makeup.

Question 2

phenotypic variability

Answer 2

variations in the observable traits, influnded by both genetic and environmental factors.

Question 3

desrcibe genetic drift

Answer 3

when chance dictates which alleles are passed on.
works along natural selection to drive evolution.
- drift has a greater effect in smaller populations. cos in larger populations chance in allele frequency evens out.

Question 4

Aneuploidy

Answer 4

abnormal number of chromosomes, often due to nondisjunction during cell division.

Question 5

polyploidy

Answer 5

presence og multiple cets of chromosomes common in plants.

Question 6

give examples of autosomal dominant disorders

Answer 6

• Huntingtons disease
• Polycystic kidney disease (PKD)
• Neurofribromatosis type 1 (NF1)

Question 7

Huntington’s disease

Answer 7

a neurodegenerative disorder - affecting motor and cognitive functions.
- by a mutation in the HTT gene on chromosome 4.

Question 8

Neurofibromatosis Type 1
(NF1)

Answer 8

tumour gorwth in nerve tissue, skin pigmentation changes
- mutations in the NF1 gene.

Question 9

Polycystic Kidney Disease (PKD).

Answer 9

formation of flluid filled cycts in the kidneys.
PKD1 or PKD2 genes are responsible.

Question 10

give examples of autosomal recessive disorders

Answer 10

cystic firbrosis

sickle cell anemia

phenylketonuria (PKU)

Question 11

phenylketonuria (PKU)

Answer 11

inability to metabolise phenylalanine, leading to intellectual disabilities.
- caused by PAH genes.

• an inborn error in metabolism.

Question 12

what mutation causes sickle cell anemia

Answer 12

mutations in HBB gene.
- abnormal heamoglobin = misshaped RBCs

Question 13

cystic fribrosis

Answer 13

respiratory and digestive dysfunciton cos of thick mucus production

• mutation in the CFTR gene

Question 14

Fragile X syndrome
- what type of syndrome is it.
- what are symptoms
- what genes are impacted.

Answer 14

1. an X-linked dominant disorder.
2. intellectual disabilities, behavioural changes.
3. expansion of CGG repeats in the FMR1 gene on the X chromosome.
   normally the CGG trplet it repeated about 5-40 times, but with the mutation, it is repeated upto 200 times.

Question 15

give examples of V-linked reccessive disorders

Answer 15

• Duchenne Muscular Dystrophy (DMD).
• Heamophillia A and B

Question 16

Duchenne Muscular Dystrophy (DMD).

Answer 16

• progressive muscle weakness and wasting.
• mutations in the DMD gene.

Question 17

give examples of mitochondrial disorders

Answer 17

• Laber’s Hereditary Optic Neuropathy (LHON).
• Mitochondrial Myopathy.

Question 18

descrive the laber’s hereditary optic neuropathy disorder

Answer 18

vission loss from damage to the optic nerve.
- accosiated with mitochondiral DNA mutations.

Question 19

what is Mitochondrial Myopathy.

Answer 19

results in muscle weakness and fatigue. again from mutations in mitochondrial DNA, affecting energy production.

Question 20

give examples of multifactorial disorders

Answer 20

• Alzheimer’s disorders
  (progressive neurodegenerative disorder affecting memory and cognitive functions.)
• type 1 & 2 diabetes.
  (metabolic disorder, from insulin resistance.

both are influenced both by genetic predisposition and lifestyle factors.

other examples = cancers, migraines.

Question 21

examples of chromosomal disorders

Answer 21

down syndrome (trsiomy 21) - intellectual disabilities.

turner syndrome - females - monosomy X

Klinefelter - in males - XXY

Question 22

what are inborn error of metabolism

Answer 22

A heterogeneous group of disorders that may be inherited or may occur as the result of spontaneous mutation.

Question 23

other than PKU, give another example of inborn errors of metabolism.

Answer 23

Gaucher Disease - accumulatio of fatty substances in cells.
- mutations in GBA gene.

Question 24

what can me done to test for and diagnose inherited diseases.
describe 4 ways.

Answer 24

carrier testing

parental screeneing

parental diagnostic testing

newborn screening

Question 25

how is carrier testing done.

Answer 25

tests if either parent is carrying a mutation to a disorder.

Question 26

how is parental screening caried out.

Answer 26

blood tests from the pregnant mum, how likely the fetus might have a condition.

Question 27

how is Prenatal diagnostic testing done

Answer 27

testes a sample of the fluid in uterus, to find whether developing fetus might have a higher risk for a condition.

Question 28

how is Newborn screening done.

Answer 28

samples newborn’s blood and to detect any disorders.
- done to all babies in ohio.

Question 29

what is edwards syndrone

Answer 29

aka trisomy 18.
- some can have a whole extra chromosome 18, some may have it only in some cells, and someimes there will only be extra sections on the same chromosome.

aka - full, mosain and partial edward’s syndrome.

Question 30

gene mutations can either be

Answer 30

Dominant or recessive

Question 31

what are numerical mutations

Answer 31

mutations that occur in the chromosome count, potentially causing aneuploidies or polyplodies.
result of cell division errors

Question 32

Structural mutations include

Answer 32

Lost, replicated, inverted fragments of chromosomes