Y2 Genetics

Question 1

[……….] is the term used to define the full set of genes that make the genetic make up of an individual

Answer 1

Genotype

Question 2

The number and visual appearance of the chromosomal material of a cell is known as [……….]. In humans, the male one is 46XY and the female one, 46XX.

Answer 2

Karyotype

Question 3

The interaction of those genes with the environment, producing a visible or observable expression of the genetic information is known as [……….]

Answer 3

Phenotype

Question 4

Organisms who have 2 copies of each chromosome are called [……….]

Answer 4

Diploid

Question 5

The molecule composed of two chains of polynucleotides that coil around each other in a double helix is called [……….]. It carries genetic instructions for the development, functioning, growth and reproduction of the organisms.

Answer 5

DNA

Question 6

A threadlike structure of nucleic acids and proteins found in the nucleus of most living cells, carrying a highly ordered sequence of linked genes is called [……….]

Answer 6

Chromosome

Question 7

The basic physical and functional unit of heredity is known as [……….]. It controls the development of one of more traits by acting as instructions to produce proteins. This basic unit is used to pass genetic information from parents to offspring.

Answer 7

Gene

Question 8

Some genes have a variety of different forms, that can be dominant or recessive. Each of these forms are called [……….] and are located at the same genetic locus (position) on a chromosome

Answer 8

Alleles

Question 9

The complete genetic material of an individual is known as [……….]

Answer 9

Genome

Question 10

Beta thalassemia

Answer 10

Autosomal recessive

Red blood cell deficiency, common in ethnicities from african/mediteranbian/asian decent. Early heart and spleen disease. Treatment blood transfusion.

Question 11

Sickle cell disease

Answer 11

Autosomal recessive

group of inherited health conditions that affect the red blood cells. The most serious type is called sickle cell anaemia. Common in African/Caribbean decent.
People with sickle cell disease produce unusually shaped red blood cells that can cause problems because they do not live as long as healthy blood cells and can block blood vessels.

Sickle cell disease is a serious and lifelong health condition, although treatment can help manage many of the symptoms.
Symptoms: Cickle cell crisis, infections, anaemia, delayed growth, stroke, lung problems.
Might need repeated blood transfusions.

Question 12

Colour blindness

Answer 12

X-linked

Question 13

Patau syndrome

Answer 13

Chromosomal

Patau’s syndrome is a serious rare genetic disorder caused by having an additional copy of chromosome 13 in some or all of the body’s cells.
Life expectancy 7-10 days, 11% live to their first birthday.

Question 14

Phenylketonuria (PKU)

Answer 14

Autosomal recessive

treatable disorder that affects the way the body processes protein. Children with PKU cannot use a part of the protein called phenylalanine. If left untreated, phenylalanine builds up in the bloodstream and causes brain damage. Does not shorten life expectancy if treated.
Treated through diet control

Question 15

Maple syrup disease

Answer 15

Autosomal recessive

Body cannot process certain amino acids, causing a harmful build-up of substances in the blood and urine. bodily fluid smell like syrup or burnt sugar. onset 5 months to 7 years, can be intermittent. Could need liver transplant. Treated through diet control

Question 16

Cystic fibrosis

Answer 16

Autosomal recessive

Cystic fibrosis (CF) is an inherited disorder that causes severe damage to the lungs, digestive system and other organs in the body.

Cystic fibrosis affects the cells that produce mucus, sweat and digestive juices. These secreted fluids are normally thin and slippery. But in people with CF, a defective gene causes the secretions to become sticky and thick. Instead of acting as lubricants, the secretions plug up tubes, ducts and passageways, especially in the lungs and pancreas. Salty sweat. life expectancy average 44 years.

Question 17

Rh negative

Answer 17

Autosomal recessive

Only a problem if baby is Rh positive. If father is Rh- there is no problem. 
Should babys and maternal blood mix antibodies can develop. this can lead to maternal blood attic the fetus in subsequent pregnancies, leading to:
Anemia.
Brain damage.
Heart failure.
Jaundice. 
Stillbirth. 
Death after birth

Question 18

Marfan syndrome

Answer 18

Autosomal dominant

Marfan syndrome is a disorder of the body’s connective tissues, a group of tissues that maintain the structure of the body and support internal organs and other tissues. Varies in severity.
Typical characteristics of Marfan syndrome include:
being tall
abnormally long and slender limbs, fingers and toes (arachnodactyly)
heart defects
lens dislocation – where the lens of the eye falls into an abnormal position

Question 19

Achondroplasia

Answer 19

Autosomal dominant

Dwarfism. Life expectancy around 70 yo.

Question 20

Autosomal recessive inheritance

Answer 20

One parent carrier- no risk

Both parents carriers- 25% unaffected, 50% carriers, 25% affected by condition.

Question 21

Long QT syndrome

Answer 21

Autosomal dominant

Affects electrical signals and predominantly the heart that causes arrhythmia. Can cause fainting, seizures and cardiac arrest. Treated with Beta blockers.

Question 22

Autosomal dominant

Answer 22

If one parent affected: 50% chance that the child is effected.
If both parents are affected: the child will have the condition

Question 23

Duchenne muscular dystrophy

Answer 23

X-linked

Affects 1 in 3500 males
Caused by mutations in DMD gene which makes dystrophin protein that helps stabilize and protect muscle fibres. Muscles without dystrophin become damaged and over time weaken and die (skeletal and heart muscles affected)
Muscle weakness starts in childhood, usually wheelchair-dependent by adolescence, typically live into their 20’s

Question 24

X-linked

Answer 24

Mothers are carriers: 
Unaffected daughter 25%
Unaffected son 25%
Carrier daughter 25%
Affected son 25%

Question 25

Edwards syndrome T18

Answer 25

Chromosomal

Serious, life expectancy 7-10 days, 12% live past their first bday. Detection rate 90%.