Q:1-A certain grassland ecosystem consists of grasses that grow on the plains, mice that eat the grains the grasses produce, weasels that eat both the grass and the mice, and hawks that eat the weasels. Which of these species will account for the smallest proportion of the biomass of this ecosystem?
Mark one answer:
The mice
The weasels
The bacteria in the soil
The hawks

Q:6-What is the first step in photosynthesis?
Mark one answer:
Light causes oxygen to pair with hydrogen, forming water for the plant
Photons present in light strike and excite electrons in chlorophyll
Water is split by chlorophyll
Nutrients from the soil are turned into carbohydrates when combined with water

Q:7-Which of the following molecules will pass most freely through the cell membrane?
Mark one answer:
Oxygen (O₂)
Glucose (C₆H₁₂O₆)
Sodium ions (Na⁺)
Water (H₂O)

Q:8-Where would aspartic acid, an amino acid with a negatively charged side chain, most likely be found in a transmembrane protein?
Mark one answer:
Outside or inside the cell
Outside the cell
Inside the cell
Within the membrane interior

Q:9-What is the purpose of the nucleolus in eukaryotic cells?
Mark one answer:
Create rRNA and the subunits of ribosomes
Provide ATP for the nucleus
Modify pre-mRNA and send it to the cytoplasm
Create mRNA and send it to the cytoplasm

Q:10-Which cellular structure is least likely to bear a membrane protein that moves hydrogen ions out of the organelle?
Mark one answer:
Golgi body
Mitochondria
Lysosome
Nucleus