Heredity & Evolution - 1 - Class 10

Weight of body depends on diet and habits. If somebody is not eating he will definitely lose weight as the body fat will be used for production of energy once glycogen reserve finishes.

Continuous variation can be defined as the variations in the phenotypic traits in which a series of types are distributed on a continuum rather than separate groups. For example body weight.

New species may be formed if DNA undergoes significant change in germ cells. Changes in DNA will be inherited by the germ cells. Germ cells which when passes to the next generation will be inherited in the subsequent generations.

Change in the chromosome number makes a change in the gametes which leads to change in the gene pool and causes variation. 

Different eye colour is a genetic variation.

The earlobe variants found in human population are free and attached.
EXPLANATION:-
All the human beings have two types of earlobes.
One of such earlobes are the attached earlobes which are attached to the skin of human being near his or her ear . 2nd earlobes are the earlobes which are not so attached rather they are hanged freely

According to Mendels laws of inheritance there is independent inheritance of two separate traits shape and colour of seeds.

Both are modifications of root while potato is a stem modification and brinjal is a fruit.

Tendrils of peas plant and phylloclade of opuntia are homologous because both of them have same origin i.e they are modified shoots but perform different functions.

Both thorn of Bougainvillea and potato are modification of stem.

There are certain fossils of ancient reptiles which have both reptilian as well as feature of birds which proves that birds have evolved from reptiles.