Chapter 12 Plant Processes
Name:___________________________
•What are the two types of reproduction?
•What is the name of the plant female reproductive organ?
•What is the name of the plant male reproductive organ?
•What is the purpose of reproduction?
•What are the two gases involved in photosynthesis?
•Where does photosynthesis occur in a plant cell?
•What is the name of the pigment which absorbs light energy?
12.1 The Reproduction of Flowering Plants
•How does fertilization occur?
–
–
Sperm cells produced in the ______________ must be able to reach eggs in the _________.
Sperm cells within ___________________ move down the pollen tube which the plant has
produced, and into the ovary.
–Fertilization occurs when a sperm cell fuses with an egg cell.
A seed is born
From Flower to Fruit
•After fertilization the following takes place:
– the fertilized egg within the _______________ develops into a ____________.
– The ovary surrounding the ______________ develops into a _____________.
– The fruit ____________________ while holding and protecting the developing seeds.
– The seeds represent the next generation once germinated and looking like a plant.
Seeds Become New Plants
•Once a seed is fully developed, the seeds stop developing and become DORMANT.
–When seeds are ____________ they are ____________and the seeds _____________ stops.
–Dormant seeds can survive long periods of drought or freezing temperature.
Once a seed is in an environment with _____________, ____________, and a suitable
_______________________(ideally about 27C or 80.6F) the seed germinates or sprouts.
Asexual Reproduction
•
•Parts of a plant are used to create a new plant without_________________________________;
•Examples: -Strawberry runners, Geranium slips, and potato eyes.
–Don’t eat______________________
12.2 The Ins and Outs of Making Food
•Photosynthesis – Converts sunlight, carbon dioxide, and water into sugar and oxygen
–Occurs in plant cell ____________________
–Chloroplasts contain __________________, a _____________ pigment that absorbs light energy.
–Chlorophyll is green because in the green light is not _______________, it is ________________.
–The overall reaction involves multiple steps:
6 CO2 + 6 H2O
C6H12O6 + 6O2
Gas exchanges occurs through leaf ___________ (stoma, singular). When ___________________
is lost it is called _____________________.
Chapter 12 Structured Notes
1
MLK 2005-2006
12.3 Plant Responses to the Environment
•Response to Stimuli
–Anything that causes a ________ in an organism, organ system, organ, tissue, or cell is a stimulus.
•Tropism - Plants growth in respond to a stimulus either:
–_____________________________ the stimulus or
–____________________________ from the stimulus:
Tropic Responses
Light = phototropism
o Stems are ______________ phototropic - moving
towards the light stimulus
o Roots are _______________ phototropic - moving away from the light stimulus
Gravity = gravitropism
o
Stems are negatively gravitropic
o roots are positively gravitropic.
Current ideas about Phototropism
•Cells produce a hormone called an auxin, indole-3-acetic acid (IAA) while growing
• Unequal distribution of _________ causes the ______________ in phototropism by affecting
the plant cell length.
– High concentration the cells become _______________.
– Low concentrations the cells become _______________.
Adaptive Value of Phototropisms
•
Roots growing ______________________ from light are more likely to find the soil, water, and minerals
they need.
Stems _____________________ the light will be able to expose their leaves so that
photosynthesis can occur.
What is the adaptive value of gravitropism? Think – Pair – Share
•
Seasonal Responses
Length of Day
•The length of day changes over a season.
• Days are longer in the summer than in the winter.
•The _________________ between day and night lengths is an important stimulus for many plants.
•Length of day is a stimulus that determines when some plants will _____________________.
Seasonal Changes in Leaves All trees lose their leaves
•Evergreens and Deciduous Trees
–______________________________ shed their needle leaves a little at a time
Chapter 12 Structured Notes
2
MLK 2005-2006
–______________________________ lose their leaves at the same time each year.
• Usually shed leaves in the fall and winter
• Tropics or areas near the ____________ have only wet and dry seasons so the deciduous
trees shed leaves before the dry season begins.
Prickly Pear Cactus
•Desert plants live with extremes in temperature, water availability and solar radiation
by adapting ______________ rather than __________________.
•Most desert plant adaptations seem to be geared towards _____________ water
loss; a difficult task since plants must "breathe" in order to photosynthesize, losing body water to the
atmosphere in the process. Breathing occurs in plant leaf _____________________.
Different Desert Adaptations:
•In their effort to survive in a hostile environment, desert plants have three adaptations types that
have developed.
•______________________ - related to the form and structure of the plant (ANATOMY)
•_________________l - related to the biological function of the plant. Such features may include:
· Accumulate water
· Self-pruning - _________________
· Plant chemically shifts temperature
•____________________- where the plant can survive
Remember plants cannot move
· Grow where there is more water
· Cracks in the sandstone - where water accumulates
Morphological features
•Fuzzy or hairy leaf surface
•Deep tap roots
•Waxy leaves
•Extensive surface roots
•Grow in shade or self-shade
•Spines instead of leaves
•Shiny, reflective leaves
•Thicker leaves
•Small leaves
12.4
Plant Growth
•All living things grow. A plant’s growth is affected by its
•Genes: sequences of DNA that code for a particular trait. Heredity the passing of traits from one
generation to the next.
•Hormones: are chemical messengers that carry information from one part of an organism to
another, produced in small quantities when genes are expressed.
•Environment: determines behavior and appearance.
Plant Hormones
•A plant hormone is produced in a part of a plant, then moves through the plant to cause a response
in all parts of the plant it contacts.
•Five classes of have been identified:
• Auxin – growth stimulator,
• Cytokinin – growth stimulator
• Gibberellin – growth stimulator
• Abscisic acid – growth inhibitor, promote dormancy, and help the plant withstand stressful conditions.
• Ethylene - growth inhibitors or "aging stimulators". A gas produced and involved in fruit ripening.
Chapter 12 Structured Notes
3
MLK 2005-2006
How Hormones Work
•
Generally they work by affecting ________ ________________, elongation and differentiation
(telling the cell what DNA sequences should be expressed).
•
Effects of the chemicals vary depending on target area, developmental stage, hormone
concentration, and interactions with other hormones.
At the cellular level, the hormones result in g_____________________, effects on enzymes, or
________________________ of cell membrane properties.
Review
1. Which of the following statements is NOT true of flowering plants?
a. Fertilization takes place within the flower.
c. They use flowers to reproduce asexually.
b. They produce seeds in fruit.
d. They are the largest group of plants in the world.
•
2. Flowers can have both male and female reproductive structures. True or False?
3. The ovule becomes a _____________after fertilization.
4. A fruit, which protects and holds the seeds, develops from the __________ of a flower.
5. Green light is reflected by chlorophyll. True or False?
6. During photosynthesis, light energy is used to split water into __________ and ____________
7. Sugar is broken down by plant cells for energy during cellular respiration. True or False?
8. Transpiration is the loss of water vapor from leaves. True or False?
9. When a tropism is _____________, a plant will grow toward the stimulus. (positive or negative)
10. A plant’s traits are determined by heredity. True or False?
11. After seeds develop fully, and before they sprout, they may become ______________.
12. During___________________, energy from sunlight is used to make sugar.
13. The loss of water through stomata is called _______________.(transpiration or tropism)
14. A change in plant growth in response to the direction of light is called_______________.
(gravitropism or phototropism)
15. Plants that have leaves year-round are ______________. (deciduous or evergreen)
16. Plants that lose their leaves at specific times of year are __________________.(deciduous or
evergreen)
17. Plant cells need carbon dioxide for
a. cellular respiration. b. phototropism.
c. fertilization.
d. photosynthesis.
18. When chlorophyll breaks down,
a. pollination occurs.
b. other pigments become visible.
Chapter 12 Structured Notes
c. red pigments disappear.
d. photosynthesis occurs.
4
MLK 2005-2006