The first living things on Earth, single-celled micro-organisms<span> or microbes lacking a cell nucleus or cell membrane known as prokaryotes, seem to have </span>first<span> appeared on </span>Earth<span> almost four billion years ago, just a few hundred million years after the formation of the </span>Earth<span> itself.</span>
        
             
        
        
        
<span>The best answer is :
</span><span>A. bacterial growth reduces the chances of fire due to oil spill because s</span>praying fertilizers on an oil soaked area stimulates growth of bacteria that metabolize the oil and it speeds the natural breakdown process.
        
             
        
        
        
Answer:
A)100mL  B)50mL  C)The second option  D)Hypoosmotic Environment
Explanation:
The average Na concentration in the seas and oceans of the world is around 3,5% which mean that in 100 ml of sea water, there is around 3,5 grams of Na.
The weight of one mol of NaCl is 58,44 grams. For 3,5 grams of NaCl, we get 3,5/58,44 = 0,060 mol of NaCl which is 0,060x1000 = 60 mmol/100ml. According to this and the information given in the question about the secretion of the salt glands', if the average sodium concentration is 600mmol/L, we have 60*10 = 600mmol/L so it would take 100 mililiters of water to excrete.
If the average Na concentration of the salt gland's secretion were 300 mmol/L, only 50 mililiters of water would be needed to excrete the same sodium load.
The second option of secretion is hyperosmotic to seawater because the concentration is higher.
Osmoregulation is the process of balancing the amount of water and salt between the body of the organism and its surrounding environment. For salt glands to be advantageous for osmoregulation, they need to be in a hypoosmotic environment.
I hope this answer helps.
 
        
             
        
        
        
Answer:
During anaphase 2, the chromosomes' centromeres break, and the spindle fibers pull the chromatids apart. The two split portions of the cells are officially known as "sister chromosomes" at this point.
Explanation:
 
        
             
        
        
        
Answer:
D. all of the above
Explanation:
Biome refers to a large and relatively distinct terrestrial region having similar climatic conditions regardless of where it occurs on Earth. The characteristic climatic conditions (temperature and precipitation being the most important ones) and soil type of each biome type determine the type of plant species found there. Therefore, each biome is characterized by specific flora.  
For example, a desert biome is a temperate or tropical biome characterized by a lack of precipitation, seasonal variations in temperature and poor soil type with low organic matter that limits plant growth. Desert biomes have only the plant species that can survive these harsh conditions.