Question

1. stomata are pores in the leaves of plants that allow gases to enter and exit the cells. during the sunniest part of the day, the leaves are most actively performing photosynthesis. during this time, which gas do the stomata allow into the leaf cells?

a oxygen
b carbon dioxide
c water vapor
d hydrogen

1. which of the following accurately describes how photosynthesis and cellular respiration are related in plant cells?

a the glucose produced by photosynthesis is used for energy in cellular respiration.
b the solar energy trapped by photosynthesis is then used to make glucose in cellular respiration.
c carbon dioxide is used in cellular respiration to produce the oxygen needed for photosynthesis.
d the glucose needed for photosynthesis is produced by utilizing solar energy in cellular respiration.

1. gardeners often create compost piles where they allow bacteria to convert grass clippings, fruit and vegetable peals, egg shells, etc. into usable organic humus to add to their gardens. in one type of composting, the compost pile is kept very wet so as to drive out any available oxygen. what type of bacteria will thrive in this type of compost pile?

a photosynthetic bacteria
b aerobic bacteria
c pathogenic bacteria
d anaerobic bacteria

1. which statement below is true of both chloroplasts and mitochondria?

a both use energy directly from the sun to drive metabolic pathways.
b both are involved in creating compounds that store energy.
c both create high energy products from low energy reactants.
d both perform cellular respiration to convert glucose into atp.

1. study the graph below.

graph: energy vs time, with reactants, products, activation energy, energy is released labels
this graph could be used to represent which cellular process?
a photosynthesis
b cellular respiration
c both cellular respiration and photosynthesis
d neither cellular respiration nor photosynthesis

Explanation:

Question 29

Photosynthesis in plants requires carbon dioxide ($\ce{CO_2}$) as a reactant. During the sunniest part of the day when photosynthesis is most active, stomata open to allow carbon dioxide into the leaf cells. Oxygen is a product of photosynthesis, water vapor is released (transpiration), and hydrogen is not a gas taken in for photosynthesis through stomata.

Photosynthesis produces glucose (using solar energy, $\ce{CO_2}$, and $\ce{H_2O}$). Cellular respiration uses glucose to produce ATP (energy) by breaking it down. Option B is wrong because cellular respiration doesn't make glucose from solar energy. Option C is wrong as $\ce{CO_2}$ is a product of respiration and a reactant of photosynthesis. Option D is wrong because photosynthesis produces glucose, not the other way around.

Anaerobic bacteria can survive and thrive in environments without oxygen. The compost pile is kept wet to drive out oxygen, so anaerobic bacteria (which don't need oxygen) will thrive. Photosynthetic bacteria need light (not mentioned here), aerobic bacteria need oxygen (which is absent), and pathogenic bacteria are disease - causing, not defined by oxygen - free environments here.

Answer:

B. carbon dioxide

Question 30