3. What is the definition of recessive and dominant? 4. What is the difference between genotype and phenotype? Write a 5 sentence
paragraph describing the difference between the two.

716 4682 5378716 4682 5378716 4682 5378

Recessive: relating to or denoting heritable characteristics controlled by genes which are expressed in offspring only when inherited from both parents.

Dominant: Refers to a trait that appears more frequently than another trait, resulting from interactions between gene alleles.

Explanation:

Genotype and phenotype differences

GenotypePhenotype

The hereditary information of the organism in the form of gene in the DNA and remains the same throughout the life.The characters of an organism which are visible are known as phenotypes.

Same genotype produces same phenotype.Same phenotype may or may not belong to same genotype.

Present inside the body as genetic material.Expression of genes as the external appearence.

The genotype is inherited from the parent to the offspring.The phenotype is not inherited from the parent.

It can be determined by scientific methods such as the polymerase chain reaction.It can be determined by observing the organism.

It is affected by genes.It is affected by genotype and environmental conditions.

For eg., Blood group, eye colour, height, genetic diseases.For eg., Weight, physique, beak of birds

an individual’s sex (i.e., whether they are a male or female) is determined by the sex chromosomes. most people have two sex chromosomes, one that is inherited from their mother and one that is inherited from their father. typically, females have two x chromosomes (xx) and males have one x chromosome and one y chromosome (xy). conditions caused by changes (“mutations”) in genes located on the x chromosome are considered x-linked.

x-linked recessive inheritance

most x-linked conditions are recessive. this means that in a person with two x chromosomes (most females), both copies of a gene (i.e., one on each x chromosome) must have a change or mutation whereas in a person with one x chromosome (most males), only one copy of a gene must have a mutation. a female with a mutation in one copy of a gene on the x chromosome is said to be a “carrier” for an x-linked condition. a male with a mutation in a gene on the x chromosome is typically affected with the condition. because females have two copies of the x chromosome and males have only one x chromosome, x-linked recessive diseases are more common among males than females. however, x-linked recessive diseases can occur in both males and females.

for x-linked recessive disorders, an unaffected carrier mother who has a mutation in a gene on the x chromosome can transmit either the x chromosome with this mutation or a “normal” x chromosome to her children. if the father is unaffected, none of her daughters will be affected and all of her daughters will be unaffected—since they will inherit at least one normal x chromosome from their father. however, each daughter will have a 50% chance of being an unaffected carrier like her mother and a 50% chance of both x chromosomes being normal.