How does the cerebral arterial circle ensure that the brain has a constant supply of blood?

Charles darwin published his theory of evolution in 1859. in what way foes modern evolutionary theory differ from the theory as proposed by darwin? a) darwin inferred that individuals can evolve, but modern generic science has shown that this is not true. b)darwin inferred that individuals do not evolve, but modern genetic science has shown that this is not true. c)modern science has disproved most of darwin's original theory of evolution, because darwin knew nothing about generations and their role in heredity. d)generic studies have shown that gene expression and other factors operate along with natural selection, but most of darwin's theory has been supported by modern science.

Which event would lead to primary succession of a forest?

What was the purpose of mendel's experiments with dihybrid crosses? a. to determine if dna was a transforming factor b. to determine if traits could be recessive c. to determine if traits affected each other d. to determine if traits had more than one allele