Plant Processes
Section 1
Photosynthesis and Respiration
A. Taking in _________________—how plants eat and breathe
1. ____________ of materials
a. Most water enters through _________ and then moves up through the
plant.
b. Water vapor exits through __________.
c. Carbon dioxide and __________ enter and exit the leaves.
2. Leaf structure and function—layers of _________
a. Epidermis—outer layer containing many ___________ to control water
loss
b. __________ layer—contains carbon dioxide and water needed for food
production
c. Food is produced in the ____________ layer.
3. ________________ and pigments
a. Chloroplasts—cell structures in which __________________ occurs
b. _______________ is green pigment in chloroplasts.
c. ____________ help plants absorb light energy to make food.
B. Food-making process
1. __________________—plant uses carbon dioxide, water, and light energy in
the presence of chlorophyll to make glucose and oxygen.
2. Light-dependent reactions—light energy splits water into oxygen and
____________; oxygen is released as a waste product.
3. Light-___________ reactions
a. __________________ and hydrogen from light-dependent reactions
combine to make glucose.
b. ___________ is used in a plant’s structure and growth.
c. Extra glucose is stored as other __________ or ____________
4. Importance of photosynthesis
a. Directly or indirectly produces ________ for almost all organisms
b. Removes carbon dioxide from and adds oxygen to ______________
C. Breakdown of food—releases __________
1. Respiration—chemical reactions that break down food molecules and release
__________
a. Glucose is broken into smaller molecules in a cell’s _____________.
b. Aerobic respiration uses __________ to break down smaller molecules
and occurs in cell’s mitochondria.
2. _______________ is important because it provides plant cells with usable
energy.
a. Energy helps plants _____________ and produce materials.
b. Waste product of respiration is __________________ which is returned
to atmosphere.
D. Comparing photosynthesis and respiration—_______ processes
1. Photosynthesis, occurring only in cells with _______________, combines
carbon dioxide and water using light energy and releases glucose and oxygen.
2. Aerobic respiration occurs in mitochondria of all cells and combines
__________ and food to release __________, carbon dioxide, and water.
Section 2 Plant Responses
A. Plant responses—changes resulting from internal and external ___________
B. ___________—a response to a stimulus resulting in growth change; can be positive
(toward stimulus) or negative (away from stimulus)
1. Some plants grow around objects they _________.
2. Plants may grow toward a _________ source.
3. ___________—downward growth of roots is a positive response; upward
growth of stem is a negative response
C. Plant hormones—control growth changes triggered by ____________
1. Ethylene—________ produced by many plants and released into the air.
a. Can promote cell growth between leaf and stem resulting in ________
drop
b. Stimulates fruit ____________ process
2. _________—controls changes related to a plant’s light response and production
of other plant hormones
3. Gibberellins—chemicals in __________ that can infect plant stems and make
them grow too tall
4. ______________—also cause fast growth through rapid cell division
5. ___________ acid—slows or stops plant growth
D. Photoperiodism—plant’s sensitivity to daily hours of light and darkness for
__________ production
1. Long-day plants—need ________ than 10 to 12 hours of darkness to produce
flowers
2. _____________ plants—want 12 or more hours of darkness to produce flowers
3. Plants that can flower within a range of darkness hours are called
_______________ plants.
Worksheet