Complete question: A phylogenetic tree shows that birds and crocodiles share many features. A hypothesis based on this tree predicts that these features are present in a common ancestor. Which of these predicted traits is supported by fossil evidence?
A) four-chambered heart
B) singing for territory
C) eggs and nests
D) singing to attract mates
Answer: (c) eggs and nests
Explanation:
A hypothesis based on phylogenetic tree shows that birds and crocodiles have ancestral connection. Fossil evidence shows that their common ancestor exhibit oviparity as a means of reproduction (i.e. laying of eggs and embryo develops within the egg), and also housed their eggs in the nest for protection against predators and other important reasons.
 
        
             
        
        
        
Mastication is just a fancy way to say chewing. Since nothing chemical is going on and the food is just being chewed, the answer is physical. 
        
             
        
        
        
B.
The Radio-ulna and digits of most primates and animals represents a homologous structure
An example of another internal structure is the genes.
The homologous chromosomes have the same genes in common. Each cell has at least two sets of chromosomes which one comes from one’s father also called as paternal chromosome and mother, called as the maternal chromosomes. These chromosomes are what makes the child obtain the characters and may depend on the traits the parents possess. Homologous chromosomes are not duplicated chromosomes or identical however, they are analogous or similar. The alleles for a specific characteristics isn’t the same but the same genes are in the same order.<span> </span>
        
             
        
        
        
A star is formed within the clouds of dust. These clouds of dust are scattered throughout the galaxy. These dust clouds are called as nebula. The turbulence inside the dust clouds rise to form knots. These knots along with sufficient mass causes gas and dust to collapse with the help of gravitational force. These sequence of steps leads to form a star.