Explanation:
The purines are ribose and deoxyribose 
 
        
             
        
        
        
It is described as relatively non specific 
        
             
        
        
        
Answer:
I found this from someone else. This is not my work, Also if this does not answer the question ask the question on here and you can see more answers. hope this helps.!
Explanation:
According to National Geographic, ostriches are a part of a very small group of birds that cannot fly because unlike most birds, their small wings are not strong enough to carry their body for flight and their breastbone isn't balanced enough for flying. Birds that are unable to fly are called ratites.
A number of scientists namely Thomas Huxley, Richard Owen, and others have tried to show that these ratites are actually related to each other and eventually, it was discovered that they all had one thing in common, the way the bones at the roof of the mouth were arranged was similar to that of reptiles rather than other birds.
Richard Owen found and assembled the remains of an extinct ostrich skeleton which was an extinct moa and contrary to already held opinion, one ratite known as tinamous did not really fit with the profile of a ratite because it could fly, even though almost grudgingly and they possessed keeled sternum which suggests that they evolved from flying birds.
DNA tests showed that tinamous evolved within ratites and not necessarily as a separate entity. The tests also showed that moas and tinamous are related.
It was also speculated that the division of the supercontinent Pangaea southern side led to the separation of flightless ratite ancestors, causing each landlocked group to evolve and become the flightless birds we know today such as the ostrich, rheas, etc.
 
        
                    
             
        
        
        
Answer:
C - ao desenvolvimento de ovos depositados por borboletas.
Explanation:
Antes de responder a sua pergunta, eu preciso te explicar que esse não é o servidor brasileiro e sim o servidor dos EUA, você deve ter percebido que toda a linguagem do site esta em inglês. Isso significa que você só deve postar perguntas em português no campo "World Languagens" mesmo que a sua pergunta seja de biologia como essa. Caso você não faça isso, a sua pergunta pdoe ser excluída, sem ser respondida.
As lagartas que surgem nas espigas de milho, são resultado do ciclo de vida da lagarta e refere-se ao momento em que os ovos depositados nas plantas de milho pelas borboletas se chocam, liberando as lagartas, que se desenvolverão e virarão novas borboletas.
É impossivel que um grão e milho vire uma lagarta, ou que o sabubo apodrecido pode gerar lagartas. Além disso, o ´processo de geração espontanea é uma teoria cientifica invalida e que não deve ser considerada.
 
        
             
        
        
        
Spermatogenesis is the process by which haploid spermatozoa develop from germ cells in the seminiferous tubules of the testis. This process starts with the mitotic division of the stem cells located close to the basement membrane of the tubules.