How many trophic levels are there in the following food chain?

algae

mosquito larvae

dragonfly larvae - trout

What kind of matter is formed when atoms of two or more elements bond?

What role do decomposers play in the cycling of material in a biogeochemical cycle?

What are three reasons for using genetically engineered organisms that make sense for a commercial farmer?

You are looking at a slide of an unknown organ that has an empty lumen with stratified squamous epithelium contacting the lumen. Deep to the epithelium is a basement membrane and then two layers of smooth muscle.

What is the main purpose of scientific models? a. The main purpose of models is to have a physical object to which to refer. b. The main purpose of models is to represent observations. c.

Identify twice substances that can cause changes in DNA

In which of the following cells can more than one nucleus be found? A. An unfertilized egg B. Neuron C. Sertoli cell D. Muscle fibre

1pt Blood is made up of A. nutrients, minerals, fats, and proteins B. oxygen, carbon dioxide, and sugar C. plasma, red blood cells, white blood cells, and platelets D. bone marrow cells and water

One of the first breakthroughs in biotechnology was the discovery of the gene that makes insulin. Part of this process involved scientists making DNA to match each possible sequence of insulin mRNA. What was the next step of this process? A.

Which of these modes of transmission require a bodily opening either natural or artificial?