Natural selection occurs to give help the best survival chance to the organisms.
Answer:
b. Nucleotides
Explanation:
Nucleic acids are examples of structures formed from nucleotides. And in relation to the composition of DNA, we have the formation of the largest cellular macromolecule, all formed by nucleotides.
The nucleotide is a group formed by the association of 3 molecules - a nitrogen base, a phosphate group and a pentose glycide. Thus, we may have variations within these ligands, such as: in DNA we have the presence of pentose deoxyribose, while in RNA we have the presence of pentose ribose.
The nucleotides have differences in relation to its nitrogen base, which can be purine or pyrimidine. Purine bases vary in Adenine and Guanine, while pyrimidine bases are classified in Thymine, Uracil and Cytosine. Purine and pyrimidine bases are complementary and each have specific binders. Thus, we have that the purine base Adenina, binds with the pyrimidine bases Timina and Uracila, while the base Guanina binds exclusively to Cytosine and vice versa.
• Homologous structures: Both Ostriches have wings similar in form to those of their ancestors, but that do not allow the birds to fly.
Homologous structures are those that have structural similarities but are different in function. For example, if we look at the anatomical structure of a bird’s wing, it is very similar in structure with a human arm. However, over the course of time they have evolved to perform different functions.
• Vestigial structures: The inner ear bones of mammals have evolved from bones that form the jaws of reptiles.
Vestigiality refers to the process in which some structure lose their function over the course of evolution in some specie but they are functionally normal in other species. Such a structure is the inner ear bones of mammals which donot perform an important function in mammals but do perform in reptiles.
• DNA sequence data: Both Genes involved in RNA replication are conserved among bacteria and animals, suggesting a common evolutionary origin.
The sequencing of genetic data is an excellent method of finding the evolutionary histories and relatedness of different organisms. This field of sciences is called phylogenetics and the mentioned example is the result of phylogenetics.
• Analogous structures: The jointed legs of insects and vertebrates arose independently, indicating a different evolutionary origin.
Analogous structures are those that have similar function but they look very different in structure or anatomy. This is because they have been evolved from different ancestors and perform different functions. One example of these structures is mentioned, The jointed legs of insects and vertebrates that look different bur perform same function.
Antibiotics can have side effects.
When children take antibiotics at the first sign of an ear infection, they are more likely to have vomiting, diarrhea, and allergic reactions because of the medicine. Also, antibiotics can kill “friendly” germs in the body and cause other problems like diarrhea.
Over-use of antibiotics is a problem.
Antibiotics can help drug-resistant bacteria grow. These bacteria are harder to kill. They can cause illnesses that are harder to cure and more costly to treat. This increases the risk of complications and side effects. The resistant bacteria can also infect other people.
Hope this helps
Answer:
Newton's first law.
Explanation:
The first law, in which an object moves forward in a straight line unless acted on by an outside force. It describes Inertia it the inherent property of the body due to which it opposes any change in its state of motion or rest. So due to Inertia, Tasha's brother's body moved forward.
