Lecture 2

Question 1

Phenotype

Answer 1

Observable trait/characteristic

Question 2

Teratogen

Answer 2

Prenatal environmental influence, environmental agent which causes harm

Question 3

Three phases of prenatal development

Answer 3

1) Germinal
2) Embryonic
3) Foetal period

Question 4

2 Developments in Germinal phase

Answer 4

1) Implantation of blastocyst

2) Development of amnion, chorion, placenta, umbilical cord

Question 5

5 Occurrences in Embryonic phase + time period

Answer 5

Time period: 3-8 weeks

1) CNS, internal organs, muscles and skeleton begin to form
2) Heart begins pumping blood
3) live and spleen begin producing blood cells
4) external features form
5) testes in males begin producing testosterone

Question 6

Foetal Phase + time period

Answer 6

Time period: week 9-birth

Pregnancy divided into three trimesters

Question 7

2 Genetic Abnormalities

Answer 7

1) Phenylketonuria (PKU)

2) Down syndrome

Question 8

2 Characteristics of Phenylketonuria (PKU)

Answer 8

1) Infants born with two recessive alleles

2) lack enzymes to convert phenylaline into tyrosine which is essential for bodily function

Question 9

Why does down syndrome happen and what results

Answer 9

1) Failure of chromosome pair #21 to split in meiosis, ends up with 3 chromosomes
2) Intellectual disability, memory and speech problems, slow motor development