Lamarckism deals with ........

Explanation:

Lamarckism is the idea that an organism can pass on characteristics that it has acquired during its lifetime to its offspring (also known as heritability of acquired characteristics or soft inheritance).
Environment influences all types of organisms. A change in environment brings about changes in organisms. It gives rise to new needs. New needs or desires produce new structures and
change habits of the organisms.
If an organ is constantly used it would be better developed whereas disuse of organ results in its degeneration.
Whatever an individual acquires (to possess) characters in its life time due to internal vital force, effect of environment, new needs and use and disuse of organs, they are inherited (transmitted) to the next generations.
The process continues. After several generations, the variations are accumulated upto such extent that they give rise to new species.