Plant Anatomy - Evolutionary Perspective Flashcards
When did plants arise and from what?
Over 440 Million years ago from Green algae.
What is the evidence that plants came from green algae?
Pigmentation, cell walls containing cellulose, starch stored in plastids.
What organisms have a ground tissue system?
All Plants and Algae
What organisms have a Dermal tissue system?
All Plants.
What organisms have a Vascular Tissue System?
Some plants.
What is Parenchyma tissue? Is it simple or complex? Where is it found?
Simple tissue found in the Ground tissue system. Made up of Parenchyma cells.
Describe Parenchyma cells.
Parenchyma cells are living, undifferentiated plant cells usually lacking a secondary cell wall. They are Totipotent.
Describe Sclerenchyma cells. Where are they found?
Develop a secondary wall and serve to support and protect the plant. Sclerenchyma cells are found in all three tissue systems. Fibers.
What is the Xylem and what does it include?
It is a complex tissue that include tracheary elements.
Which cell is bigger: Parenchyma or Collenchyma?
Parenchyma cells.
What are the two types of tracheary elements?
- Tracheids. 2. Vessel elements.
What are Tracheids?
Less specialized type of conducting cell. Do not have perforations.
What are Vessel elements?
They, unlike Tracheids, contain perforations, which are areas lacking both primary and secondary walls.
What are Perforation Plates?
They are the part of the wall bearing the perforation(s).
What are the principle conducting cells of the phloem?
Sieve elements.
What are the two types of Sieve elements?
- Sieve cells. 2. Sieve tube elements.
What are sieve-tube elements associated with?
Specialized Parenchyma cells called: Companion cells
What tissues that comprise the Xylem are dead and which are alive?
Dead: Vessels, tracheids (Tracheary elements), xylem fibers. Alive: Certain Parenchyma cells.
What are Sieve cells associated with? What is it made up of?
Albuminous cells. Which are comprised of specialized Parenchyma cells.
What is a main difference between sieve cells and sieve tube elements?
Sieve tube elements contain sieve plates.
What are sieve tubes?
The end on end, in a longitudinal series of stacked sieve tube elements.
What function do Parenchyma cells serve in the Xylem?
Storage.
What function do fibers have in the Xylem?
Support; sometimes storage.
What function do Sclerenchyma (Fibers; Sclereids) cells have in the Phloem?
Support, sometimes storage.
What are the 2 tissues in the dermal tissue system?
- Epidermis. 2. Periderm.
What are the 3 types of tissues in the ground tissue system?
- Parenchyma. 2. Collenchyma. 3. Sclerenchyma.
What are sclereids comprised of?
Sclerenchyma
What is the Cohesion-Tension Theory?
Water is pulled up the tracheary elements, because water molecules stick together (cohere) via hydrogen bonds.
What elements of the Xylem only has pits?
Tracheids.
What is Primary Growth?
Elongates the axis of a plant.
What is Secondary Growth?
Increases the girth of the plant.
Where is cell division limited to in plants?
Regions of parenchyma cells call meristems.
What are the 3 types of meristems?
- Apical. 2. Lateral. 3. Intercalary.
What do Apical Meristems do?
They extend the length of the plant body.
What do Lateral Meristems do?
They extend the gridth of a stem or root.
What are Intercalary Meristems?
These are regions of growth situated between two regions of mature (non-growing) tissue. (This is how grass grows upwards).
What is the Protoderm?
It matures to form the epidermis.
What does the ground meristem form?
Ground Tissue.
What does the Procambium form into?
Forms vascular system.
How does branching occur in the root?
From within a tissue layer called the Pericycle.
What type(s) of cells make up the pith?
Just Parenchyma
What type(s) of cells make up the cortex?
Parenchyma and Collenchyma
