Chapter 2 - Genetic Basis of Child Development Flashcards

Question

What does a homozygous phenotype produce?

Answer 1

A phenotype for whatever the alleles are for since they will both either be dominant or recessive

Answer 2

The alleles in a pair of chromosomes differ

Answer 3

A phenotype for whatever the dominant allele's chemical instructions are for (the recessive allele is ignored)

Answer 4

One allele does not dominate another completely (alleles blend) - The resulting genotype often falls between the phenotype associated with either allele - E.g., Red and white flower --> pink flower

Answer 5

When more than one allele for a trait is considered to be dominant - Alleles both equally expressed - E.g., Blood type

Answer 6

Quantitative inheritance, where multiple independent genes have an additive or similar effect on a single quantitative trait (e.g., height, skin colour, eye colour, weight)

Answer 7

Every person with at least one of the alleles would have the disorders and typically, they would not live long enough to reproduce - Dominant alleles that produce fatal disorders soon vanish from the species

Answer 8

- Sickle-cell disease - Albinism - Cystic fibrosis - Phenylketonuria (PKU) - Tay-Sachs disease - Cooley's anemia

Answer 9

15 in 1000 births; Changes the shape of red blood cells and blocks blood flow to organs, depriving the affected organs of blood and oxygen

Answer 10

1 in 15,000 births; Skin lacks melanin which causes visual problems and extreme sensitivity to light

Answer 11

1 in 3,000 births among European Americans; Excess mucus clogs respiratory and digestive tracts (lung infections are common)

Answer 12

1 in 10,000 births; Phenylalanine accumulates in the body and damages the nervous system causing cognitive issues

Answer 13

1 in 2,500 births among Jews of European descent; The nervous system degenerates in infancy, causing deafness, blindness, cognitive issues, and during the preschool years, death

Answer 14

High blood pressure, Huntington's disease, extra fingers, migraine/headache, schizophrenia, Marfan syndrome

Answer 15

Fatal disease characterized by progressive degeneration of the nervous system and caused by a dominant allele found on chromosome 4

Answer 16

Very tall; long arms; host of physical problems such as heart defects

Answer 17

Constructing a detailed family history before a woman becomes pregnant

Answer 18

Because autosomes contain so much genetic material

Answer 19

Nearly half within 2 weeks

Answer 20

Down syndrome/Trisomy 21, which is caused by having an extra 21st chromosome often provided by the egg and results in cognitive impairment, health problems, and different facial features

Answer 21

During cell division and meiosis, one of the chromosomes doesn't separate properly

Answer 22

Males because unlike females, they only have one X chromosome so they are less likely to be able to mask a recessive allele

Answer 23

Klinefelter's syndrome, XYY complement, Turner's syndrome, XXX syndrome. hemophilia, fragile-X-syndrome, red/green colourblindness, night blindness, Duchene muscular dystrophy, and diabetes insipidus

Answer 24

XXY; 1 in 500 to 1,000 male births; tall, small testicles, sterile, below normal intelligence, passive

Answer 25

XYY; 1 in 1,000 male births; tall and in some cases have below-normal intelligence

Answer 26

X; 1 in 2,500 to 5,000 female births; short, limited development of secondary sex characteristics, and problems perceiving spatial relations

Answer 27

XXX; 1 in 500 to 1,200 female births; normal structure but delayed motor and language development

Answer 28

Branch of genetics that deals with inheritance of behaviour and psychological traits

Answer 29

Identical twins that come from a single fertilized egg that splits in two (they have the same genes that control body structure, height, and facial features)

Answer 30

Fraternal twins that come from two separate eggs fertilized by two separate sperm (genetically, fraternal twins are just like any other siblings; on average, about half their genes are the same)