Inheritance (2.13)

Question 1

Define the following terms: Gene, Allele, Genotype, Phenotype, Recessive, Dominant, Incomplete dominance, Homozygote, Heterozygote

Answer 1

GENE: The basic unit of heredity passed from parent to child. Genes are made up of sequences of DNA and are arranged, one after another.
ALLELE: same sequence of nucleotides at the same place along a DNA.
GENOTYPE: a persons unique sequence of DNA
PHENOTYPE: physical expression of the genotype
DOMINANT: An allele of a gene is said to be dominant when it effectively overrules the other
RECESSIVE: trait that is only expressed when genotype is homozygous
INCOMPLETE DOMINANCE: a form of Gene interaction in which both alleles of a gene at a locus are partially expressed
HOMOZYGOTE: having two identical alleles of a particular gene/genes
HETEROZYGOTE: having two different alleles of a particular gene/genes.

Question 2

Using a genetic diagram, predict the genotype and phenotype outcomes of a cross between two parents who are heterozygous for Cystic Fibrous

Answer 2

Mum
F. f

Dad. F. FF. Ff

        f.        Ff.                     ff

Question 3

Using a genetic diagram, predict the genotype and phenotype outcomes of a cross between two parental plants that are heterozygous (for flower colour possible phenotypes are red, white and pink)

Question 4

Give the genotype of an individual who is a symptomless carrier of a recessive disease

Answer 4

The individual with carry one dominant gene without the disease and the recessive gene that causes the disease making them a carrier.