UNIT2 KA4 antenatal and postnatal screening

Question 1

What does dominant mean

Answer 1

Only 1 is required for a trait to be expressed

Question 2

What are features of autosomal recessive

Answer 2

Can skip generations
Male and females are equally effected
Individuals can be a carrier without expressing the trait

Question 3

When can u carry out chrorionic villus sampling

Answer 3

11-14 weeks

Question 4

What are the two types of ultrasound scans called

Answer 4

Dating scan

Anomaly scan

Question 5

What is a genome

Answer 5

All of the alleles a individual has

Question 6

What are the 4 types of disorders

Answer 6

•Autosomal recessive. (cystic fibrosis)
•Autosomal dominant
(Huntington’s disease)
•Autosomal incomplete dominant ( skin cells)
•sex link recessive (haemophilia)

Question 7

What is a karyotype

Answer 7

The display of homologous chromosomes a individual passes

Question 8

How long and what is the dating scan

Answer 8

8-14 weeks

Determines the stage of pregnancy and due date

Question 9

What does heterozygous mean

Answer 9

An individual with 2 different alleles

Question 10

What is a disadvantage of chorionic villus sampling

Answer 10

Small risk of miscarriage

Question 11

What does recessive mean

Answer 11

2 are required for a trait to be expressed

Question 12

What is a disadvantage of amniocentesis

Answer 12

Takes weeks to develope karyotype

Question 13

What are different types of antenatal tests

Answer 13

• Ultrasound imaging
• Biochemical tests- blood + urine
• Diagnosis tests - amniocentesis + chronic villus sampling

Question 14

What is a autosomal

Answer 14

Non sex chromosomes

Question 15

What is postnatal screening

Answer 15

Health checks that are carried out after birth to detect the presence of conditions/abnormalities

Question 16

What is the sickle cell trait

Answer 16

One abnormal gene but does not display symptoms

Question 17

What are alleles

Answer 17

The different forms of a gene eg brown, blonde or red hair

Question 18

What type of mutation is PKU

Answer 18

substitution

Question 19

When can u carry out amniocentesis

Answer 19

15-18 weeks

Question 20

What is a carrier

Answer 20

An individual who carries a recessive trait without expressing it

Question 21

What type of disorder is PKU and what system does it effect

Answer 21

Recessive

Inborn error of metabolism

Question 22

What are features of sex linked recessive

Answer 22

More common in males

Carried on X chromosomes

Question 23

What is a gene

Answer 23

1 type of characteristic eg hair colour

Question 24

What can antenatal screening help identify

Answer 24

Down syndrome
Spina bifida
Cystic fibrosis
Muscular dystrophy

Question 25

What are features of incomplete dominant

Answer 25

Male and females are equally effected | Heterozygous traits are more common

Question 26

How long and what is the anomaly scan

Answer 26

18-20 weeks | Used to detect only physically abnormalities in the developing fetus

Question 27

What does homozygous mean

Answer 27

An individual with 2 identical alleles

Question 28

What are features of autosomal dominant

Answer 28

Males and females equally effected | No carriers- heterozygous would express the trait

Question 29

What are phenotypes

Answer 29

Physical characteristics

Question 30

What are advantages of chronic villus sampling

Answer 30

Given karyotype immediately

Question 31

How many alleles are required to express PKU

Answer 31

2

Question 32

What is the treatment for PKU

Answer 32

Placed on restricted diets that lacks phenylalanine

Question 33

What are the 2 types of diagnosis tests

Answer 33

Amniocentesis | Chronic villus sampling