For any terrestrial planet in the solar system, the core would be the densest layer, and the crust would be the least dense layer.
 
        
                    
             
        
        
        
The correct answer is D Fish ( someone asked me to explain why d is the answer) A sponge obviously doesn’t have a brain, a hydra is an organism and organisms don’t have brains ( hydra also doesn’t have eyes)
        
                    
             
        
        
        
The answer is B. hope you get it
        
             
        
        
        
The system that is responsible for breaking down food and releasing essential nutrients and other substances that the body needs and requires is the digestive system.
        
                    
             
        
        
        
Answer:
The correct answer is B. <em>The cells in the outer skin surface appeared flat, whereas the cells in the cross section were not flat.</em>
Explanation:
The epidermis is made up of five cell layers, which have different functions: Stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, and stratum corneum.   
- <u><em>Stratum basale</em></u> is the <em>innermost germinative, single, basal layer of the epidermis </em>composed of basal cuboidal-shaped cells. These cells are the precursor of keratinocytes, this is why this layer is also called germinativum. In this basal layer, there are also Merkel cells as well as melanocytes.
- <em><u>Stratum spinosum</u></em> refers to the keratinocytes which produce keratin. 
- <u><em>Stratum granulosum</em></u>, this is the layer where keratinization begins. Cells produce hard granules that change to keratin and lipids as they ascend. 
- <u><em>Stratum lucidum</em></u> is conformed of densely compressed cells, which begins to flatten and appear indistinguishable between each other.
- <u><em>Stratum corneum</em></u> is the most external layer, composed of dead, flattened cells which are released regularly in a process known as desquamation.