Answer:
The correct answer is A
Explanation:
Eukaryotic cells have a nucleus containing their DNA, whereas prokaryotic cells do not have a nucleus. 
 
        
                    
             
        
        
        
Chemoreceptor is a specialized sensory receptor cell, which responds to a chemical substance and generates a biological signal.
The type of chemoreceptor responsible for our sense of smell is called olfactory receptor. It is also known as odorant receptor, these are found in a small patch of tissue high inside the nose. These cells directly connected to the brain.
        
             
        
        
        
Answer:
The elemental is required in very small amount. (Ans. A)
Explanation:
Trace element is also known as micro-nutrient. It is also defined as any chemical element required by living organisms in a minute or small amounts which is usually part of the vital enzyme (cells produced by catalytic protein).
Exact needs of trace elements vary among species, like commonly required plant trace elements are cooper, zinc, manganese, boron, and molybdenum. Animals commonly required iodine, manganese, and cobalt.
Absence of necessary plant trace elements required by plants in the soil causes deficiency disease, lack of animal trace elements used by animals in the soil may not harm plants, but, animals feeding on those plants develop their deficiency disease. 
So, the adjective trace means that the elemental is required in a very small amount. 
 
        
             
        
        
        
Answer:
Meiosis involves two cell divisions
Explanation:
Mitosis and meiosis are two kinds of cell divisions and one of the main differences between the two is that meiosis goes through <u>2 nuclear divisions</u>. 
Meiosis has Meiosis I and Meiosis II division. In Meiosis I, the number of chromosomes in the daughter cells are only half of the parent cells. This is why it is called a reduction division, because the chromosomes will be reduced by half. In Meiosis II, the daughter cells will have the same number of chromosomes as the parent cells, which in this case is the daughter cells of meiosis I.