2.4 Characteristics and Inheritance
-Genetics is the study of inherited characteristics called traits.
*Pea plants can have red flowers and white flowers.
Flower color is carried as one of the genes in a homologous pair of chromosomes.
This gene comes in 2 varieties.
We call this variation of genes--> Alleles
Therefore in pea plants, gene for flower color has 2 alleles.
One for red flower plant
One for white flower plant.
Here red traits are dominant to the white trait.
Red flower color is the dominant trait.
White flower color is the recessive trait.
-If a pollen from pure breeding red
flowering pea plant is pollinated with
pure breeding white flowering pea plant,
all the offspring in the next generation
(F1 generation) will be red.
Representing alleles
-Allele for the dominant trait is represented by upper case letter.
-Allele for the recessive trait represented by lower case letter.
-When an individual has same alleles--> Homozygous
That individual is known as homozygote
-When an individual has different alleles-->heterozygous
That individual is known as heterozygote.
Eg:
Red flower allele -R
White flower allele -r
-Combination of RR alleles will produce a red flower
-Combination of rr alleles will produce a white flower.
-Combination of Rr alleles will produce a red flower because
Red flower trait is dominant.
, -When working out the possible characteristics of offspring, it is important to refer
back to meiosis and movement of genes and alleles as gametes are produced.
-Genetics is the study of inherited characteristics called traits.
*Pea plants can have red flowers and white flowers.
Flower color is carried as one of the genes in a homologous pair of chromosomes.
This gene comes in 2 varieties.
We call this variation of genes--> Alleles
Therefore in pea plants, gene for flower color has 2 alleles.
One for red flower plant
One for white flower plant.
Here red traits are dominant to the white trait.
Red flower color is the dominant trait.
White flower color is the recessive trait.
-If a pollen from pure breeding red
flowering pea plant is pollinated with
pure breeding white flowering pea plant,
all the offspring in the next generation
(F1 generation) will be red.
Representing alleles
-Allele for the dominant trait is represented by upper case letter.
-Allele for the recessive trait represented by lower case letter.
-When an individual has same alleles--> Homozygous
That individual is known as homozygote
-When an individual has different alleles-->heterozygous
That individual is known as heterozygote.
Eg:
Red flower allele -R
White flower allele -r
-Combination of RR alleles will produce a red flower
-Combination of rr alleles will produce a white flower.
-Combination of Rr alleles will produce a red flower because
Red flower trait is dominant.
, -When working out the possible characteristics of offspring, it is important to refer
back to meiosis and movement of genes and alleles as gametes are produced.
