<span>1. Hind limes tend to be sturdier, stronger and longer. </span>
<span>2. The hind limbs are more firmly attached to the spine.</span>
 
        
             
        
        
        
C: lack of water during long periods..
        
                    
             
        
        
        
Answer: Option C
Explanation:
The amitochondriate eukaryotes may have genes that have been derived from purple alphaloproteobacteria because they do not have the mitochondria which is needed to optimize energy production in the presence of oxygen, can live and exist in a condition with little to no oxygen which is a characteristic of proteobacteria and hence are anaerobes obtaining energy by anaerobic respiration. They may have also undergone the endosymbiont theory but due to their environment which has little to no oxygen. They do not have a need for the mitochondria organelle and in the process lose this organelle.
 
        
             
        
        
        
Acoustic emissions technician.
Acoustical physics.
Aerospace engineer
Air traffic controller
Ariel survey flight supervisor.
Artificial intelligence developer.
Assistant research officer.
Astronomer
        
             
        
        
        
Answer:
c. the plant root growing down into the soil
Explanation:
The plant root going down deep into the soil is an example of positive gravitropism. Gravity pulls everything towards the center of earth i.e. downwards and roots follow the direction of gravity automatically by growing downward towards soil that is why it is known as positive gravitropism. In short we can say that root favors the direction of gravity. 
Shoot on the other hand show negative geotropism/gravitropism  i.e. it grows towards the opposite direction of gravity. Shoot grow towards upside direction i.e. away from the surface towards sky.