Science : Ch 09 – Heredity and Evolution

Acquired traits are the changes which do not occur in the DNA of the individual or in its genes thus they are not passed from one generation.

Inheritance from the previous generation provides both a common body design and subtle changes in it due to inaccuracies during DNA copying. However, greater diversity will be generated if sexual reproduction is involved

All ofsprings of F1 generation were tall with round seeds which shows that both Tallness and round seed are dominant traits. However, new combinations were seen in F2 generation which showed that the tall/ short trait and the round/wrinkled seed trait are independently inherited

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.

Hormones and enzymes are proteins, and the formation of any specific protein is controlled by a particular gene. Fat biosynthesis occurs through metabolic reaction.

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 wings of an insect and a bird have distinct structures but they carry out the same function of fying. Therefore, they are analogous organs

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.

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.

Some dinosaurs had feathers, although they could not fy using those feathers. Birds seem to have later adapted the feathers for fight. This means that birds are closely related to reptiles and have evolved from them