Inheritance Flashcards
AA
Who found out about Inheritance
Gregor Mendel
What was His experiement
conducted experiments with Pisum Sativum (garden pea)
Cross Pure bred with plants of contrasting traits
eg yellow seed crossed with green seed
Gene
Factors which determines a inherited characteristic
Allele
Alternative form of a gene
Dominant
Always expressed if present , has the ability to mask effects of other alleles
Recessive
Expressed in absence of a dominant allele, usual masked by a dominant allele
represented in Lowercase
Homozygous
Both alleles of a particular characteristic are the same
Heterozygous
Both alleles of a particular characteristic is different
Hemizygous
Only having half of the alleles, usual always in males due to having 1 x chromosome
Phenotype
Physical characteristic/appearance that is determined by the alleles expressed
DNA profiling
a sample of the DNA is cut at particular base sequences and placed on a bed of gel. Electrophoresis results in the pieces of DNA forming a banding pattern dependent on the size of the DNA fragment. This banded picture is the person’s DNA profile or fingerprint.
Advantages to DNA profiling
Can help detect/trace hereditary diseases at an early age = better chance to get treated
Identify alleles that have mutated
Progeny
Offspring
Autosomal Dominant.
Two affected parents producing a UNaffected child
Autosomal Recessive
Two UNaffected parents producing a Affected child
X-Linked Dominant
Fathers with affected trait passes it onto ALL of their daughters as their Y chromosome is passed down to their sons
X-Linked Recessive
Mothers with affected trait passing it onto ALL of their sons
Principle of Segregation
The trait for a allele is segregated/separated during formation of gametes
Genetic counselling
Advice given to parents or couple about to the risk that an inherited condition may be passed onto their offspring. Making them have an informed decision about if they wish to have a child or not
Principle Of Inheritance
inherited characteristics are
controlled by genes, and that each
gamete receives one set of genes.
Huntingson’s Disease
Autosomal Dominant
Characterised by occasional involuntary flailing movements of the arms and legs. In addition, the
person often has difficulty making voluntary
movements of the limbs
PKU ( Phenylketonuria )
Autosomal Recessive
controls the production of an enzyme called phenylalanine hydroxylase (This enzyme converts the amino acid phenylalanine to tyrosine) If not present, then phenylalanine
will accumulate in the bloodstream and become toxic
Cystic fibrosis
Autosomal Recessive
Children with the condition
suffer from chest infections, lack of digestive enzymes and increased salt loss
Treatment for Cystic fibrosis
a blood sample is usually taken from the baby’s heel within two
to three days after birth.
IS given a special diet low in
fat and high in carbohydrate and protein
Red and green colourblindness
X Linked Recessive
Individuals who are unable to distinguish between the two colours
Haemophilia
X-Linked Recessive
Process which the blood clots
slowly or not at all
ABO blood group
Autosomal Co-Dominant
Symptoms: Cramping Drowiness
Treatment: Light Therapy
Electrophoresis
Process of pieces DNA pieces placed on a bed of gel and an electric current was passed through the gel (electrodes) Producing a dna banding pattern
Ethical Issues for DNA profiling
Discriminsion can cause the results of their genetic profiles to pay more/less for health cover according to their risk of disease
