Chapter 30 - Monohybrid inheritance Flashcards
1
Q
What is inheritance?
A
Receiving genetic material from parents
2
Q
Define genotype
A
Genetic make-up of an organism
3
Q
Phenotype
A
Physical appearance
4
Q
Homozygous
A
Same alleles for a characteristic
5
Q
Heterozygous
A
Different alleles for a characteristic
6
Q
Dominant
A
Allele visible in phenotype
7
Q
Recessive
A
Only shows in genotype is homozygous recessive
8
Q
State the 7 steps in creating a genetic diagra
A
- Parental Phenotype
- Parental Genotype
- Gametes
- Fertilisation
- Offspring Genotype
- Offspring Phenotype
- Ratio
9
Q
State the 4 different genetic ratios
A
Aa x Aa 3:1
Aa x aa 1:1
AA x aa 4:0
Codominant cross 1:2:1
10
Q
Explain codominance
A
Both alleles have an effect on the phenotype. They are equally dominant or recessive
11
Q
Explain Albinism
A
- Little or no melanin in eyes, skin and hair
- Organism with NO melanin = albino
- Organism with LITTLE melanin = albinoid
- Albinism is a genetic mutation
12
Q
Describe sickle cell anaemia
A
- Red blood cells have crescent shape
- Abnormal haemoglobin called Haemoglobin S
- Sickle cells deliver less oxygen
- Red blood cells can break or get stuck
- This causes lots of pain
- It is a recessive allele
- Normal people suffer from malaria, suckle cell people do not
13
Q
Explain the different blood groups in terms of dominance
A
AB are codominant
O is recessive
14
Q
Explain sex linkage
A
- Gene that is only found on sex chromosomes is defined as a sex-linked gene
- Sex linked diseases are faulty genes on sex chromosomes
- X-chromosome is larger than Y-chromosome
- Therefore females will have two alleles for certain characteristics, where males have just one
15
Q
Describe haemophilia
A
- Impairs blood clotting
- More likely to occur in males
- Y chromosome has no allele to cancel out the fauly gene on the X-chromosome
- It is a recessive allele on the X-chromosome
