2.4 Variation And Inheritance Flashcards
Describe and compare the terms discrete variation and continuous variation.
Discrete variation is characteristics controlled by a single gene.
Continuous variation is when most characteristics are controlled by more than one gene and are described as having polygenic inheritance.
What is discrete variation controlled by?
What is continuous variation controlled by?
Discrete variation is controlled by a single gene.
Continuous variation is controlled by polygenic inheritance.
Describe the following terms: gene, allele, phenotype, genotype, dominant, recessive, homozygous, heterozygous and P, F1 and F2.
A gene is a short section of a chromosome which codes for a protein that controls a particular characteristic. Each gene has a different DNA base sequence, meaning they code for different proteins.
The different versions of a particular gene are called alleles. Alleles are represented using upper and lower case letters.
The physical appearance of an organism is known as the phenotype. E.g. having red hair is a phenotype.
The genotype of an organism is a statement of the alleles it has for a characteristic.
