Topic 3 - Genetics Flashcards
Examples of genetic differences that shows variation in population
Natural eye colour
Natural hair colour
Examples of genetic and environmental differences that explains variation in population
Skin colour
Height
Weight
Exam performance
Environmental factors that show variation in a population
Piercings
Tattoos
Scars
Example of homozygous recessive
bb
Example of homozygous dominant
BB
Example of heterozygous
Bb
What is genotype?
The alleles we have
What is phenotype?
The characteristics we have determined from alleles
What is an allele?
A different form of the same gene eg B = brown eye. b = blue eye
What are gametes?
Sex cells. Sperm and egg cells. Haploid cells
How many chromosomes does a zygote have?
- Diploid
What is meiosis?
Cell division only in the reproductive organs
What does meiosis produce?
Four daughter cells. Each with half the number of chromosomes which results in genetically different haploid gametes.
Describe the DNA structure
Double helix. Strands linked with complimentary base pairs joined together by weak hydrogen bonds. Sugar phosphate backbone.
What are the complimentary base pairs?
A adenine + T thymine. C cytosine + G guanine
What is the genome?
The entire DNA of an organism
What is a gene?
A section DNA molecule that codes for a specific protein.
What is a chromosome?
Long coiled up molecules of DNA found in the nucleus of eukaryotic cells.
Dominant
Dominant alleles will determine what characteristic is present
Recessive
Both alleles must be recessive for the organism to display the characteristic
What is a zygote?
A fertilised egg from the sperm fusing with the egg.
what chromosome do males have?
XY
What chromosome do females have?
XX
What is monohybrid inheritance?
The inheritance of a single characteristic
What are most phenotype features the result of?
Múltiples genes rather than a single gene inheritance.
What is genetic variation that influence phenotype?
Different characteristics as a result of mutation and sexual reproduction
What is environmental variation that influence phenotype?
Different characteristics caused by an organisms environment
What was the outcome of the human genome project?
It has helped identify 1800 genes related to disease, which has huge benefits for medicine
Prediction and prevention of diseases (medical application for the projects research)
If doctors knew what genes predisposed people to what diseases, we could get individually tailored advice on best diet and lifestyle to avoid problems. Doctors could check us regularly to ensure early treatment if we develop a disease.
Testing and treatment for inherited disorders (medical application for the projects research)
Inherited disorders caused by faulty alleles in a persons genome. From the HGP scientists can identify genes and alleles that cause an inherited disorder a lot quicker. Once allele identified, people can get tested for it. Better treatments could develop or cure disease.
New and better medicines (medical application for the projects research)
HGP has shown common genetic variations and how bodies react to diseases and treatments for them. Scientists can now design new drugs tailored to a particular genetic variation. More effective treatments can be made with fewer side affects.
How does genetic variation arise within a population?
There’s usually extensive genetic variation within a population of a species and these arise through mutations
Do mutations have any affect on phenotype?
Genetic mutations have no effect to phenotype. Some mutations have a small effect on phenotype. Rarely a single mutation will significantly affect the phenotype.
