Inheritance Basics, Monohybrid and Dihybrid Inheritance Flashcards
What is a genotype?
The genetic makeup of an organism that determines the characteristic a person may have.
What is a phenotype?
The visible characteristics seen in a person as a result of genotype and the environment.
What is a gene?
A section of DNA that codes for a polypeptide.
What are alleles?
Different versions of the same gene.
What is a locus?
The position of a particular gene on a DNA molecule.
In diploid organisms, describe the arrangement of chromosomes.
Chromosomes occur as homologous pairs, so there are 23 types of chromosome, but 2 of each, meaning that there are 46 in total.
For each gene, how many loci will there be and why?
There are 2 loci for every 1 gene. This is because of homologous pairs of chromosomes.
What does heterozygous mean?
The alleles present are different - either dominant or recessive.
What does homozygous mean?
The alleles present are the same.
They will either both be dominant or both recessive.
What does homozygous dominant mean?
Both alleles are dominant, so the dominant trait will display.
What does homozygous recessive do?
Both alleles are recessive, so the recessive trait will display.
Briefly describe what co dominance is.
Both alleles present are dominant, so both features are represented.
What is monohybrid inheritance?
Where a single gene is inherited.
What does the law of segregation state?
In diploid organisms, characteristics are determined by alleles that occur in pairs. Only one of each pair of alleles can be present in a single gamete.
If both parents have 2 dominant alleles, what percentage of offspring will have the dominant/recessive trait?
100% dominant
0% recessive
