In a plant, what is formed by a group of xylem vessels? A. a cell
B. a tissue
C. an organ
D. an organ system

Which image shows labeled organelles that are present only in plant cells?

Consider the following reaction: 2h2 + o2 —> 2h2o a) what are the reactants in this reaction? b) what are the products in this reaction? c) how many molecules of oxygen are used in this reaction?

The long-term increase in the average temperature on earth is referred to as _[blank]_. global cooling ozone cooling global warming ozone warming