Patterns of Inheritance Flashcards
Phenotype
The characteristics displayed by an organism
Genotype
The alleles an organism has
Intraspecific
Differences between individuals of the same species
Interspecific
Differences between different species
Continuous variation
Quantitative-
Any feature that can be measured
Can be controlled by genes and environment
Non- distinct categories
Discontinuous variation
Qualitative-
Any feature that can’t be measured
Controlled by only genes
Distinct categories
Allele
Form of a gene
Phenotypic variation - genetic factors
Polygenic:
* more than one gene controls it (can be affected by the environment)
Monogenic:
* only 1 gene controls it (not affected by the environment)
Phenotypic variation - environmental factors
Etiolation:
* plants grow abnormally long and spindly due to not enogh light
Chlorosis:
* plants don’t produce enough chlorophyll due to a lack of Mg or Fe
Genetic Variation
- Crossing over
- Independent segregation of chromosomes
- Random fertilisation
Meiosis
Gene
A sequence of nucleotide bases that codes for a protein/ polypeptide
Dominant
An allele that is always expressed when present
Recessive
An allele that is only expressed when both are recessive
Homozygous
When the 2 alleles are the same
Heterozygous
When the 2 alleles are different
Locus
Where on the chromosome the alleles are
Codominance
Both alleles are expressed and neither is recessive
Example: Sickle-cell
can create a carrier of the gene
Monohybrid
Dihybrid
Inheritance of 2 characteristics controlled by different genes
