Answer:
These homologous structure indicates a common ancestry
Explanation:
When 4 organisms show homologous structures, they indicates they belongs to a common ancestor from where the changes takes place in them.
The organs which are structurally  dissimilar but functionally same are called as homologous organism.
 
        
             
        
        
        
Answer: O cytoplasm: protects cell structures
Explanation:
 
        
             
        
        
        
-carbohydrates contain carbon , hydrogen and oxygen
-also known as saccharides 
-glucose is a hexose monosaccharide (composed of 6 carbons )
-two structural variations: alpha α and beta β glucose ,in which the OH group on carbon 1 is in opposite positions 
- glucose : polar and soluble in water due to the bonds that form between the hydroxyl groups and water molecules 
-glycosidic bond : bond formed between two glucose molecules by a condensation reaction forming a disaccharide 
-fructose +galactose =sucrose 
-galactose +glucose = lactose 
- starch :many alpha glucose molecules can be joined by glycosidic bonds to form two slightly different polysaccharides 
- one of the polysaccharides of starch is called amylose 
- amylose : formed by alpha glucose molecules joined together only by 1-4 glycosidic bonds 
-amylopectin: both 1-4 and 1-6 (every 25 glucose subunits )glycosidic bonds between alpha glucose molecules. 1-6 glycosidic bonds cause branching 
-glycogen : more branches than amylopectin . Compact so ideal for storage . Speeds up the process of storing and releasing glucose molecules required in the cell.Insoluble 
-hydrolysis reactions opposite of condensation reaction 
-cellulose:beta glucose molecules. Join together by alternate beta glucose molecules turn upside down 
- straight chain molecule: cellulose 
-cellulose molecules make H bonds with each-other forming microfibrils. Microfibrils join together to form macrofibrils which combine to produce fibres