(a) Easy to grow
(b) Short life span
(c) Easily distinguishable characters
(d) Larger size of flower
(e) Self pollinated

(a) The woman produces ova with ‘X’ chromosome
(b) The man produces sperms with X and Y chromosome which actually determines the sex of the baby. 

Yes, geographical isolation gradually leads to genetic drift. This may impose limitations to sexual reproduction of the separated population. Slowly the separated individuals will reproduce among themselves and generate new variations. Continuous accumulation of those variations through a few generations may ultimately lead to the formation of a new species.

It depends on our perspective through which we try to evaluate evolution. If complexity in body design is the parameter to define evolution, then human beings are more evolved than bacteria. Bacteria are unicellular while human beings are multicellular. Bacteria show cellular level of organization, while human beings show organ system level of organization. In terms of complexity human beings are definitely highly evolved
compared to bacteria.
 But when we compare the ability of survival, then situation is quite opposite. Human beings are living in almost every part of the earth but they can live only on land. Moreover, in extreme environmental conditions, human beings make artificial facilities to counter the adverse conditions. This means their body is not adapted to withstand extreme climatic conditions. Bacteria, on the other hand, are known to be present almost everywhere on earth. They are known to live even in some of the harshest conditions; like Sulphur spring, crater of volcano, etc. Bacteria can survive in highly acidic environment and they can survive extreme temperatures. From this angle, bacteria can be considered
as more evolved than human beings. 

All the human races appears to be different but they have a large number of common characters. The list of common characters can be very long but we can make a shorter list.
• Similar size of brain.
• Bipedal locomotion
• Hair of body.
• Ability to handle tools.
• Ability to communicate using language.
• Highly complex social behavior.
• Same body design
All these characters show a common ancestry for all human races. Moreover, the fact that all human beings are able to interbreed keeps them under the same species. 

Inherited characters	Acquired characters
These traits alter the genotype and phenotype.	These traits alter the phenotype only.
These traits are transmitted to the next generation.	These traits are not transmitted to the next generation.
These traits are the result of genetic recombination.	These traits are the result of organism's response to environmental challenges.
Example: hair colour, eye colour, skin colour. etc.	Example: muscular body, ability to excel in a certain field, etc.

Acquired characters are acquired due to individual’s response to external stimuli. Let us take the example of a certain cricketer who is an excellent batsman. He could become an excellent batsman because of several reasons. Some of them could be; his keen interest in the game, timely support from his family and friends, proper coaching at the right age and timely selection in the cricket team. All the cricketing ability cold be acquired by him because of the way he responded to all the challenges and opportunity. But this does not mean that the son of this cricketer would become an excellent cricketer; because  cricketing ability is not an inheritable character.

In fact, acquired characters just alter the phenotype of an individual. It has no effect on genotype. A character can only be inheritable when it changes the genotype of individual. Hence, acquired characters are not inherited. 
 

The apparent structures in an organism are termed as morphological structures. Morphological structures can be easily seen by all of us. Molecular structure is about the structure of biomolecules which are the integral components of organisms. We see lot of diversity all around us. This diversity is possible because of diversity in morphological structures. This shows that morphological structures are least stable. Life which began as simple forms on the earth in now composed of many complex forms. But in spite of all the evolution which have taken place through millions of years, the structure biomolecules remains the same. A DNA is same in a human and in a mouse. A protein has same structure in a bird and in a fungi. So, the molecular basis of life has not changed through all these years. This shows that evolution has exhibited a greater stability of molecular structure when compared with morphological structure.