Diganme una introduccion de los sistemas de el cuerpo humano por favor ayudenme

When analyzing tree rings, what do scientists assume a thin ring indicates?

Some birds look for food near cattle and other livestock. the movement of the cattle churns up the ground, making insects available to the birds. the cattle appear to be unaffected by the presence of the birds. what kind of relationship exists between the birds and the cattle? o a. parasitism o b. commensalism o c. predation o d. mutualism

Acertain species of fish can have either long or short fins. the allele for long fins is dominant over the allele for short fins. a heterozygous, long-finned fish is crossed with a homozygous, short-finned fish. of the offspring, will have long fins and be , and will have short fins and be .