BISC 002 Chapter 7

1) Which of the following is an autotroph?

pine tree

2) Photosynthesis contributes to plant growth by _____.

taking in carbon dioxide and making sugars (carbohydrates)

4) What is the function of stomata?

gas exchange

5) Through what structure(s) do plants obtain most of their water?

roots

6) What name is given to the membranous sacs found within a chloroplast?

thylakoids

7) What are grana?

stacks of membranous sacs

8) If you provided your shade-tolerant plants with their preferred wavelength of light, but only minimal amounts of water, which of the following would you expect to occur?

decreased amounts of ATP being produced by the plants

9) Which of the following equations best summarizes photosynthesis?

6 CO2 + 6 H2O → C6H12O6 + 6 O2

10) In photosynthesis, redox reactions ultimately transfer electrons from ______ to ______.

H2O… CO2

11) Which of the following is produced during the light reactions of photosynthesis?

O2

13) The products of the light reactions of photosynthesis are ______.

ATP and NADPH

14) The color that we see when looking at a pigmented object is ______.

the wavelengths that are reflected or transmitted by the pigmented object

15) If a plant appears blue to us, what wavelength of light is being reflected?

blue

16) The energy of wavelengths that appear ______ is least useful to photosynthesis.

green

17) What is responsible for the yellow-orange coloration of leaves in the fall?

carotenoids

18) What is one reason why plants have accessory pigment molecules, like chlorophyll b and carotenoids?

to absorb energy in parts of the electromagnetic spectrum that chlorophyll a cannot

19) What name is given to a discrete packet of light?

photon

20) The shorter the wavelength of visible light, the ______.

greater the energy

21) When a molecule absorbs a photon, one of its electrons is raised to the ______ state.

excited

23) Where are photosystems located?

thylakoid membrane

24) What compound is found at the reaction center of a photosystem?
A

chlorophyll a

25) The light reactions of photosynthesis take place ______.

in the thylakoid membrane

26) ______ is the source of the oxygen gas released by a photosystem.

Water

27) Which of the following is the source of electrons for the light reactions?

H2O molecule

28) Which of the following is found in both cellular respiration and in the light reactions of photosynthesis?

electron transport chain

29) In photosynthesis, an H+ ion gradient forms across the ______.

thylakoid membrane

30) The Calvin cycle makes direct use of ______ to make ______.

CO2, ATP, and NADPH… sugar

31) C4 plants conserve water by ______.

B) keeping their stomata closed when the weather is hot and dry

32) CAM plants conserve water by ______.

opening their stomata only at night

33) Refer to the accompanying figure. Plant cells that contain the organelle responsible for photosynthesis are concentrated in cells of the ______.

leaves

34) Refer to the accompanying figure. Which of the following is true regarding the behavior of a chlorophyll molecule as it absorbs a photon?

The energy of a photon raises an electron to the excited state.

36) How many times must the Calvin cycle turn for the plant cell to be able to produce one molecule of glucose?

six

37) One of the compounds that is a direct output of the Calvin cycle is ______.

G3P

38) The first step of the Calvin cycle is the incorporation of ______ into ______.

CO2… RuBP

39) The last stage of one complete turn of the Calvin cycle involves ______.

regeneration of RuBP

44) Why do some plant species require shaded conditions while other plant species require bright sunlight?

Different species of plants have different pigment molecules that utilize different wavelengths of light.