Inheritance Flashcards
What is inheritance?
Inheritance is the passing on of characteristics from one generation to the next
What is an inheritable trait?
The inheritable trait is the trait being passed on eg. hair colour
What does gene loci mean?
The location of the gene along the chromosome
What are homologous pairs?
Two of the exact same chromosome
What is an allele?
All the different forms of a gene, that will result in different gene products
What is a gene?
A section of DNA that contains the sequence of nucleotides needed to create a gene product
What is a phenotype?
Physical or biochemical characteristics of an organism that are the result of gene expression and the environment
What is a dominant allele?
A dominant allele is an allele always expressed when present, as it overpowers any recessive allele
What is a recessive allele?
A recessive allele is an allele only expressed if there are 2 copies of the allele
What is a genotype?
The two sets of alleles an individual has inherited by the individual’s parents
What is independent assortment?
The random assortment and distribution of chromosomes that happens during meiosis 1 but after crossing over
What is incomplete dominance?
When genes in a heterozygous individual are both expressed but blend together to create a new phenotype
What is codominance?
When genes in a heterozygous individual are both traits are expressed independantly eg. white and brown cows
What is a punnet square?
A prediction to see what trait can be produced by crossing genes
What are the two different types of cells?
Somatic - every other cell other than your sex cells
Sex cells - Gametes that are haploid
What are epigenetics?
Epigenetics are the environmental factors that interact with your genetic material to affect your phenotype
What are some examples of epigenetics?
Cellular processes
- enzymes
- wastes
Chemical factors
- adding chemical groups to DNA (histone-modifying - DNA is condensed tighter making genes less likely to be expressed)
Mutations
Post - Translation factors
- how cells fold
Environmental factors
- UV light
- diet
- dying hair
- temperature
What is complete dominance?
When the presence of only one dominant allele results in the expression of only that gene
FOIL method
First, Outside, Inside, Last
To find potential gametes
What is true breeding?
When both parents are homozygous, and would produce offspring that would carry the same phenotype
What are linked genes and unlinked genes?
Linked genes are close together on the same chromosome, while unlinked genes are located on different chromosomes or are on the same chromosome with a huge distance between them
Unlinked genes have an unlikely chance of being inherited together, while linked genes are likely of being inherited together
What is a test cross?
when an individual expressing the dominant phenotype but with an unknown genotype is crossed with a homozygous recessive individual.
The results will indicate whether the individual with the dominant phenotype is homozygous dominant or heterozygous
What are the linked ratios
1:0.1:0.2:1
0.1 and 0.2 are substantially lower and are recombinant chromosomes
What are the unlinked ratios?
1:1:1:1 and 9:3:3:1
Are linked genes separated during independent assortment?
Linked genes are not separated during independent assortment, however, they can occasionally be separated through crossing over
What is a recombinant chromosome?
A chromosome which is not identical to one of the homologous chromosomes in a diploid cell as it a result of alleles crossing over
What are dihybrid crosses?
Dihybrid crosses allow us to predict the potential genotypes of offspring for two genes. They also help with seeing whether genes are linked or unlinked
