Laurita and Trey notice that the two hermit crabs in their class prefer peanut butter over the crab food from the pet store. They conclude that all hermit crabs prefer peanut butter to the crab food. Why is their conclusion flawed? A) They have made a valid conclusion. B) They should have given the crabs more choices of food C) They should design an experiment with a control and use a much larger sample size. D) They should design an experiment to test the preference of the two crabs with a control.

How energy flows through each level in this energy pyramid. is all the matter and energy from one level transferred to the next level?

16. which of the following accurately describes a step within transcription? a. dna polymerase uses one strand of rna as a template to put together nucleotides. b. the dna strand is used as a template for which a complementary rna strand can be produced. c. the rna strand forms a template by which dna can be built. d. the rna strand is produced within the cytoplasm.

You will create a molecular clock model for an arthropod gene. follow these guidelines to make your model: . your timeline will span from 90 million years ago to the present. the common ancestor in your model is an arthropod that lived 90 million years ago. the gene that you'll track codes for a protein in the species venom . the dna sequence youll track contains 10 nitrogen bases. you can choose the order of the bases and where the mutations occur. this gene mutates at a rate of approximately 0.76 base pairs every 17.1 million years. to build your model,/ calculate the estimated time period it takes for 1 base pair to mutate. the first time period will only show the common ancestor. at the beginning of the second time period, three lineages will diverge from the common ancestor, each with a different mutation in their gene sequences. the first and third descendant species will survive for the rest of the timeline. the second descendant species was extinct 50 million years ago. calculate how long it will take for one full base pair mutation to occur. explain your reasoning by constructing a mathematical equation