Answer: pressure changes
Valves of the heart open and close due to pressure changes
Explanation:
The veins are the blood vessels possessing valves. And because they carry blood away from the heart, the valves helps to prevent back flow of blood due to the low pressure of blood found in the veins.
Thus, Valves of the heart open and close due to pressure changes
Answer:
The correct answer is option A) "Sequence of bases".
Explanation:
Even though DNA most of the time is comprised entirely of only four different nucleotide bases (adenine, thymine, guanosine and citosine), it is the sequence of these bases that allows DNA to carry a vast amount of hereditary information. The genes that carry the hereditary information are translated according to the sequence of the DNA bases. The information is translated by triplets of bases (codons) that correspond to different amino acids that are added to new synthesized proteins during translation.
Answer:
C Darwin
Explanation:
Charles Darwin, the father of evolution theorised that within any population, there exists variation in traits which help the animals adapt to their environment and help them survive.
In the same vein, he believed that the breeds of dogs are all one species, but they have incredible genetic diversity.
Therefore, Charles Darwin first realized that variation mattered, even though he didn't know the exact mechanism.
Answer:
By identifying the bones as being homologous structures and by proposing that humans, bats, and dolphins share a common ancestor.
Explanation:
