In flatworms, the is/are used to gather food. a. ​nephridia b. ​contractile vacuoles c. ​malpighian tubules d. ​flame cells e. ​pharynx

I’m stuck on this question cuz i’m stupid sksksksk

Pls in your opinion, what are the limiting factors that might affect the growth or diversity of our ecosystem? respond to this question in claim, evidence, reasoning format. 1. make your claim (i are the limiting factors that might affect the growth or diversity of our 2. follow the claim with 3 pieces of evidence. evidence may be taken from the reading, the videos, previous lessons, or googled answers. site sources, too. 3. use reasoning to explain why you chose your evidence.

What does polymerase chain reaction (pcr) do? o a. separates dna fragments by size o b. cuts a dna sample into fragments o c. provides an overall picture of a person's chromosomes o d. makes more copies of a sample of dna