Download Title - Iowa State University

Leader: Chelsea
Course: Bio 212(2)
Instructor: Vleck
Supplemental Instruction
Date: 10/23/12
Iowa State University
1. Name the purposes of the following structures and the different types:
A. Roots: Used for uptake of water and nutrients, support and storage.
Monocots: Fibrous root system.
Eudicots: Taproot.
B. Stems: Used for support, photosynthesis, storage, reproduction and defense.
Stolons: Horizontal stems that grow across the surface.
Rhizomes: Below grow horizontal stems.
Tubers: Nutrient storage expansions at the tip of a rhizome.
Bulbs: Stems are underground and leaves used for storage.
C. Leaves: Used for photosynthesis, defense and reproduction.
Monocots: Parallel veins.
Eudicots: Branching veins.
2. Leaves have the following three types of tissue, how are they different?
A. Epidermis with stomata: Outer layer with waxy cuticle that acts a barrier for
movement of molecules in or out of the leaf.
B. Mesophyll: Ground tissue, most functions such as photosynthesis, storage and
support.
Pareynchma: Site of plant metabolism.
Collenchyma: Used for the growth of stems.
Sclerenchyma: Used for support, but dies at maturity.
C. Vascular: Functions as a transporter.
Xylem: Transports water and minerals from the roots.
Phloem: Transports organic nutrients made from photosynthesis.
3. What occurs in each step:
A. Primary growth: Apical Meristem tissue is initially undifferentiated and then
differentiates to become the three layers. As the plant takes up water it will grow
upwards or in length.
B. Secondary growth: The cells will add girth or increase the diameter.
4. What is etiolation? Why does this occur?
How the seedlings respond to the dark, their stems will longer, reduction of
chlorophyll, root growth and leaf size. This happens because of many reasons, such
as natural selection, the phytochrome changes due to absorption of a photon.
5. What does the phytochrome do?
A. Governs shade response
B. Induces see germination
C. Regulates timing of flowering.
6. What is a photoperiod?
The timing of flowering is due to changes in seasons, because of differences in the
amount of light. Like a clock for the plant.
7. Phototrophism uses blue light to do what?
Grows towards the light and the cells elongate on the shaded side.
Plants:
Structure, growth & response
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