38. A student wants to test the hypothesis that catalysts speed up chemical reactions. She decides to use beef liver since she knows that the liver contains catalysts that speed up chemical reactions in mammals. She sets up her reaction tubes as follows: test tube 1 has the
reaction chemicals and no liver. Test tube 2 has liver but no reaction chemicals. Test tube 3 has the reaction chemicals and a small piece
of liver. She observes the following: (1 point)
Test Tube 1 Small gas bubbles form
Test Tube 2
No reaction
Test Tube 3 Vigorous bubbling, test tube hot

The diagram below represents a marine food web and a process that can harm the human population. each circle represents an organism and the smaller dots inside them represent a toxic substance. what is being represented and how does it harm the population? the diagram represents biological half-life, in which toxins build up in organisms higher up on the food chain, and this can negatively impact humans who consume the organisms and the toxic substance. the diagram represents biomagnification, in which toxins build up in organisms higher up on the food chain, and this can negatively impact humans who consume the organisms and the toxic substance. the diagram represents the process by which different organisms prey upon each other; this can impact the human population by reducing the number of organisms that do not contain the toxin. the diagram represents the way that toxins are metabolized by living organisms, with those at greater trophic levels able to metabolize more efficiently than those at lower levels. this means that those at higher tropic levels are safer for humans to consume compared to the organisms at lower trophic levels.

Which of the following statements is true? a. there are more chromosomes in an organism than there are genes. b. there are more genes in an organism that there are chemical bases. c. dna is made of sugar, phosphate, and carbon. d. genes are found in specific locations on a chromosome.

The tubes transporting minerals and water upward are called ?