My Answer: Vestigial organs
Why?: " Vestigial organs are physical structures that were fully developed
and functional in an ancestral group of organisms but are reduced
and unused in the later species."
Hope I helped! :D
        
             
        
        
        
➜ <u>Mendel conducted breeding experiments with garden peas</u>:
[i] He studied plants (pure) of a tall/short varities.
[ii] He crossed them and obtained F1 progeny.
[iii] He found that F1 progeny was all tall plants.
[iv] He selfed the (hybrid) plants if F1 progeny.
[v] He found that in F2 progeny there were tall as well as short plants.
[vi] The three quarter plants were tall and one quarter was short.
 (or any other contrasting character may be taken).
<u>Note</u>: Here, F1 means <u>First fillial generation</u> and F2 means <u>Second fillial generation</u>.
 
        
                    
             
        
        
        
Answer:
Yes, bacteria and viruses both are considered as living things 
 
        
             
        
        
        
The second one due to the fact that pioneer plants come in much later
        
                    
             
        
        
        
Answer:
<h2>
There are different theories that was proposed regarding the evolution.</h2>
Explanation:
Spontaneous generation theory states that life arises from some non-living thing or component. An experiment was carried out where it was believed that maggots arises from a piece of flesh. So, they believe that maggots (living) arises from flesh (maggots).
Theory of biogenesis states that living organisms arises from living organisms.  To support the theory Pateur performed an experiment and proves that living organism arises from living organisms.