How does summation operate in a post-synaptic cell? a). it adds up all of the previous action potentials and releases one of that value. b). post-synaptic cells do not fire. c). input from many cells is required for it to fire. d). sodium ions are moved from one cell to the next in an additive way.

Plz genetic engineering can be applied to many fields including medicine and agriculture. which of the following is a medical application of genetic engineering? a. giving crop plants recombinant dna so that they would be resistant to herbicides. b. examining a persons pedigree to determine whether they can carry a gene for a genetic disease. c. analyzing a persons dna to see how closely they are related to another person. d. certain genes into bacteria so that they will produce a needed medicine.

The finches on the galapagos island were similar in form except for variations of their beaks. darwin observed that these variations were useful for: attracting a mate defending territory building nests gathering food

Which event would lead to primary succession of a forest?