Answer:
there are two types of cell one eukaryotic cell that have true nucleus (genetic material enclosed in membrane) and membrane bounded organelles and other is prokaryotic cell that donot have have true nucleus (genetic material dispersed in cytoplasm) and membrane bounded organelles.
similarities between PC and EC is that both contains cell membrane, ribosomes (not a membrane bounded organelle) .
examples of PC are bacteria , paramecium,fungi etc
examples of EC are plant and animal cells
there are two names for cell membrane i.e plasmalemma, cell surface membrane, 
selectively permeable or semipermeable means cell only allows those material to pass through its cell membrane which it needs.this cell'ability is important because to protection against the poisonous substance and to maintain cell needs . 
 
        
             
        
        
        
This is your perfect answer.
Variegated leaves have green parts (where the cells contain chlorophyll) and white parts (where there is no chlorophyll). Only the parts that were green become blue/black with iodine solution, showing the importance of chlorophyll in photosynthesis. ... This is evidence that chlorophyll is required for photosynthesis.
        
             
        
        
        
The most effective way to keep dry land from becoming more arid is to use sustainable agricultural practices.
The right answer is "plant a tree belt"
The event of increasingly arid dry land or desertification is an event where the land becomes a very dry lack of water, vegetation, and also wild animals.
 
        
                    
             
        
        
        
Answer:
Organisms often preserved by carbonization include fish, leaves and the woody tissues of plants. permineralization or petrifaction takes place in porous materials such as bones, plants and shells
  
        
                    
             
        
        
        
Mutualism describes the ecological interaction between two or more species where each species has a net benefit.[1] Mutualism is a common type of ecological interaction. Prominent examples include most vascular plants engaged in mutualistic interactions with mycorrhizae, flowering plants being pollinated by animals, vascular plants being dispersed by animals, and corals with zooxanthellae, among many others. Mutualism can be contrasted with interspecific competition, in which each species experiences reduced fitness, and exploitation, or parasitism, in which one species benefits at the "expense" of the other. Mutualism is often conflated with two other types of ecological phenomena: cooperation and symbiosis. Cooperation refers to increases in fitness through within-species (intraspecific) interactions. Symbiosis involves two species living in proximity and may be mutualistic, parasitic, or commensal, so symbiotic relationships are not always mutualistic.
Mutualism plays a key part in ecology. For example, mutualistic interactions are vital for terrestrial ecosystem function as more than 48% of land plants rely on mycorrhizal relationships with fungi to provide them with inorganic compounds and trace elements. As another example, the estimate of tropical forest trees with seed dispersal mutualisms with animals ranges from 70–90%. In addition, mutualism is thought to have driven the evolution of much of the biological diversity we see, such as flower forms (important for pollination mutualisms) and co-evolution between groups of species.However, mutualism has historically received less attention than other interactions such as predation and parasitism.