Hello!
An initial observation is the first thing a scientist notices about a topic before conducting the experiment. We can see that it is the first thing in the paragraph in this case, that dandelions grow as unwanted weeds in many lawns.
The hypothesis is the guess about the result of an experiment made before the experiment is conducted. In this case, it is that a weed killer (Killimal) would kill all the dandelions while leaving the grass healthy. This is not specifically a guess made by the scientist, but more like a prediction he wanted to verify.
An independent variable is the variable being changed in the experiment by the scientist. Here, it is whether Killimal was sprayed or not.
The dependent variable is the variable being measured, and the one being affected by the independent variable. His observation would be whether the grass and dandelions would be killed. This is because the weed killer would be directly affecting whether or not these would be killed.
The control variables are ones which are kept the same in the experiment as to not interfere with the final results. In this case, it would be the density of dandelions, the amount of sunlight, and the amount the plants were watered. These were kept exactly the same, as they could've affected the dependent variable if changed.
The control group was the one that is not impacted by the independent variable. The control group makes sure that it actually is the independent variable affecting the dependent, and it isn't some outside unknown variable. This would be the plot without the Killimal.
The experimental group is the one being experimented on from the independent variable. This would be the plot with the Killimal. 
Hope this helps!
 
        
             
        
        
        
Answer: Detritivores improve the nutritional value and the texture of the soil: This makes the soil productive to plant life which translates to availability of food for the herbivores and carnivores like human beings. They however do not complete the energy cycle as their wastes are energy products that need to be decayed.
Decomposers help in converting the leftovers of animals and plants to useful substances for other living organisms. They are mainly bacteria and fungi. Have you ever wondered what would happen if the decomposers and consumers were not in the ecosystem?
Detritivores play a very important in the cycle as they are the consumers of dead leaves, old skin, carcasses and manure. They include millipedes, earthworms and slugs that feed on dead plants and animals but leave some parts and their feces that are converted to energy by the decomposers. Players in the energy cycle function hand in hand, a decomposer is found at the lowest part of the cycle as it deals with the remains. They complete the energy cycle. The roles of the decomposers and detritivores almost coincide.
Hope this helps !!! Good luck !!! ;)
 
        
             
        
        
        
Answer:
La principal diferencia que hay entre un espermatozoide y una célula de nuestro pelo es que el espermatozoide corresponde a una célula reproductiva haploide que contiene sólo la mitad del material genético del organismo mientras que las células en nuestro cabello tienen el material genético completo.
Explanation:
 
        
             
        
        
        
Answer:
The process of photosynthesis is energy-storing because the process converts light energy into chemical energy, which is stored in the bonds of glucose.
 
        
             
        
        
        
The correct answer is option C) A wet spring before vegetation is growing. A lack of roots holding soils and sediments together and an over-abundance of water can result in mass movements.