Chapter 20-patterns Of Inheritance

When leaves look pale or yellow. This occurs because the cells aren’t producing enough chlorophyll. The lack of chlorophyll reduces the ability of the plant to make food by photosynthesis.

Lack of light- in the absence of light, plants will turn of their chlorophyll production to conserve resources. Mineral deficiencies - for example, a lack of iron or magnesium. Iron is needed as a cofactors by some of the enzymes that’s make chlorophyll, and magnesium is found at the heart of the chlorophyll molecule. If eithier of these elements are lacking plants can’t make chlorophyll therefor go yellow. Virus infections- when viruses infect plants, they interfere with the metabolism of cells. A common symptom is the yellowing in the infected tissue. A common symptom is yellowing in the infected tissue.

Sexual reproduction involving meiosis, and the random fusion of gametes at fertilisation.

A characteristic that can take any value within a range

Genetic and environmental

Polygenes - controlled by a number of genes

A characteristic that can only appear in specific discrete values

Mostly genetic

One or two genes

The inheritance of a single gene

Occurs when two different alleles occur for a gene- both of which are equally dominant. Usually meet in the middle and form a different colour

Some charactersics are determined by genes carried on the sex chromosomes

Have more than two versions of a gene

Used to show the inheritance of two genes

X2=sum of (observed - expected) squared divided by expected

Is the interaction of genes at different loci on different chromosomes

Found gene A and gene B on same chromosomes

Autsomal two genes found on same chromosome Whereas dihybrid inheritance they are found on different chromsomes

When gene loci is further apart means there is a higher chance of a different phenotypic ratios

Monogenic inheritance- inheritance of one gene Dihybrid inheritance- inheritance of two genes