Science : Ch 09 – Heredity and Evolution

A single copy of ‘T’ is enough to make the plant tall whereas both copies have to be ‘t’ for the plant to be dwarf. Therefore, Tallness is a dominant trait whereas dwarfness (t) is a recessive trait

The Foremost attribute are always supreme. Tallness is a dominant trait as a single copy of ‘T’ is enough to make the plant tall, while two copies have to be ‘t’ for the plant to be short.

Sexual reproduction Require exchange of genetic materials of male and female gametes to form

During sexual reproduction, both mother and father pass their genes to their children, thus determining their traits; or Attribute features

The two versions of a trait which are brought in by the male and female gametes are situated on copies of the same chromosome. Each parent contributes one copy of the gene for a particular trait.

The character of the cross will be cross fertilization, which is the transfer of pollen from one plant to the stigma of fower; borne on a distinct plant of the same species.

Asexual reproduction will not result in variation as there are no gametes involved. Movement of individuals from one habitat to another will not afect the DNA.

One of the conclusions of this theory is that the processes of genetic drift—random change in gene frequency—operate in different ways in two isolated population groups and make them more and more different from each other.

The cross between RR yy and rr YY seeds will obtain RrYy ofspring which will exhibit round and yellow phenotype, as these traits are the dominant ones.

The sex of the children will be determined by what they inherit from their father. A child who inherits an X chromosome from her father will be a girl and the one who inherits a Y chromosome from him will be a boy

The reduction in the weight of an organism due to starvation is not genetically controlled as it will not change the DNA of the germ cell.