Answer:
Absorption and secretion would be impossible within the digestive tract. 
Explanation:
Epithelium is one of the tissues found in humans. It is classified as either simple or stratified depending on the number of cell layers. Simple epithelial tissues have one layer of cells while stratified have many layers of cells. Based on the shape, epithelial tissues can either be squamous, columnar or cuboidal. 
Due to the single-layer of the simple epithelial tissues, they line the walls of secretory or absorptive organs e.g organs of digestive tract. The stratified epithelium is majorly for protective function due to the number of cell layers it possess and not a good type of epithelium for locations where absorption and secretion of substances is common e.g digestive tract.
Hence, if a genetic mutation causes a person's digestive tract to have stratified columnar epithelium instead of simple columnar epithelium, ABSORPTION AND SECRETION of chemical substances, which is a key feature of organs (stomach, intestine) that make up digestive tracts, will be impossible. 
 
        
             
        
        
        
Answer:
B(sperm production)
D(appearance of secondary sex characteristics)
Explanation:
 
        
                    
             
        
        
        
Im confused about the question can you explain
 
        
             
        
        
        
Answer:
It occurs to create innovation in the existing technology.
Explanation:
A technological advancement is an attempt to develop current materials, devices, products or processes by further understanding of science.  technological advancement provides innovations of existing technology or formation of new technology in order to better the life style and make easier our work. If the technological advancement did not occur, we are unable to increase efficiency of various instruments and machines.
 
        
             
        
        
        
Answer: D
Explanation: Because new dog breeds are made when people mix two different breeds together to make another breed