Genetics Flashcards
Who and how was inheritance discovered
Gregor Mendal was the first to discover genetics through an experiment with pea plants
Whats the genotype
the organism allel pairs
What are allel pairs
allele is one of two or more versions of DNA sequence
Whats Hetrozygous
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two different allel for a trait
Homozygous
have the same alleles for a trait
What happens during fertailization
Gametes fuse creating new individuals
Whats the phenotype
The observable characterstics or outward expresstions of an allele pair
Whats a Dihybrid Cross
when there are two pairs of characterstics, each allele is distributed independantly
Mendal’s Law of independant assortment
Random distribuation of alleles during gamete formatoin genes on seperate chromosomes sort independantly during meiosis
Genetic recombination
The possible number of genes due to independant assortment can be caluclauted using the formula 2^n
where n is the number of chromosomes pair
What are the genetic disroders in humans
- Recessive genetic disorder
- Dominant genetic disorder
Cystic fibirirs
caused by a defective gene responsible for the production of memeberane protein:
it affects mucus secretion, hinders digestion clogs and obstructs respiratory pathways to the lungs
Albinism
caused by the absence of the melanin pigment in skin, hair, and eyes, resulting in no colour in the skin and hair
Humington’s disease
affects the nervous system
Achondropiasia
affects growth
Tay sacks disease TSD
the responsible gene is located at the 15th chromosome
it inhibts the enzyme stoping it from digesting a fatty acid called Gand-liosides, thus, it gets stored in the brain causing the brain cells to inflate and cause mental deterations
Galactosemia
The body’s inability to digest Galactose
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Carrier (trait carrier)
A person who is hestrozygous for a recessive disorder
What a Pedigress
What
a diagram that traces back inhertiance back to several generations looking for a specific disorder to identify its nature
What’s the significance of the Pedigress and an example of it
it si used ot study inhertiance patterns in humans
Comples Patterns of ingeritance
1.Incomplete Dominance: hetrozygous phemotype is an intermediate phenotype between the two homozygous phenotypes
2.Co-Dominance: Occurs when a gene is not dominant to another gene as in Sickle-cell Amenia
3.Multiple Alleles: when traits are determined by more two alleles just like blood types in humans
What blood type is considered an example of alleles and co-dominance
The ABD blood type
Fur colour in rabbits
There are four genotypes that determine the colour of a rabbit’s fur: C, c, c^ch, c^h
The dominance sequence: C > c^ch > c^h > c
What are the dominant and recissive genes in rabbits fur
Dominant: C Gene
Recissive: c Gene
