Lab 3: Plants Part 1: Plant Form and Function Flashcards
which species did we bring back from lab 1 in this lab?
we brought back the a.thaliana seedlings that we grew in lab 1.
What is the root and shoot system in plants?
it is the way plants acquire resources from below group and above ground via continuous network of veins known as vascular tissues
What are the basic organs of a plant? What do they do?
the basic organs of the plant are left, stem and shoot.
The leaves capture light energy via photosynthesis
The stems maintain plant structure and transport water, nutrients and sugars
Roots absorb water and nutrients from the soil
What are buds?
Buds are usually what identifies a stem, and its where organs differentiate
What are the three major plant tissue types and what do they do?
the three tissues are: the dermal tissue, the vascular tissue and the ground tissue
the dermal tissue is the outer layer of cells covering the plant and is composed of the epidermis and the cuticle. Hairs called trichomes also might be present
The vascular tissues run throughout the whole plant, and it is composed of the xylem and phloem
The ground tissue is the tissue that fills the space between the epidermis and the vascular tissue. This area depends on the plant whether it serves a purpose for photosynthesis, support, food storage, and protection
What is a petiole? and what is a node?
a petiole is what the leaf has that attaches the blade of the leaf to the stem of the plant. The point of attachment of the petiole and the stem is called the node
What are the three patterns of leaf arrangement on the stem in plants?
- alternate (spiral)
- opposite (pairs)
- Whorled (3 or more on the same node)
What are the two leaf shapes a leaf can be?
- it can be simple (one leaf)
2. It can be compound leaf –> divided into leaflets
What is a primary root and why is it important?
a primary root is the first root that the seed sends into the soil when it germinates its also called a radical root. Little roots extend from the primary root and form the root system
What are two types of primary roots?
- taproot system –> when the primary root is the largest and most important root system
- fibrous root –> plant has more than one main root forming
how does leaf shape effect photosynthesis?
larger the leaf, the more sunlight it can take in and more co2 it can take in
when might a taproot system be an advantage over fibrous roots?
when you are looking to anchor the plant stronger
How would these organs (leaves, roots and stems) be different in desert plants and tropical plants?
In deserts, there should be bigger leaves, taproots and and a larger stem in order to absorb more water
in tropical places, it can be any shape or size because it will absorb moisture from the environment
What is the function of the epidermis?
it is the outermost layer of the cells.
- the cuticle is a waxy covering on the outside of the plant
What is the function of the cortex?
it is the tissue region just interior to the epidermis. It may contain cells for storage of starch, support cells and chloroplasts for photosynthesis (these are usually close the outside of the stem)
What is the function of the pith?
the pith is the central part of the stem and it is composed of loosely arranged storage cells
What is the function of the vascular bundle? what is it composed of
strands of conductive tissue spaced in a circle around the pith. The bundles are composed of xylem and phloem. Theres also many fibres located outside the phloem that serve as support
what is the characteristics of xylem?
xylem is red stained, thick walled cells located next to the pith
What is the characteristics of phloem?
phloem is located next to the cortex, and it is thin walled and irregular shaped
what is parenchyma?
parenchyma is part of the group tissue cells and it is used for the storage of food and participates in metabolic processes
What is an upper epidermis?
it is the outer layer of cells on the upper surface of the leaf; it is covered by a non-cellar cuticle (for protection)
what is the palisade mesophyll and where is it?
it is the dense layer of cells directly below the upper epidermis and it is the primary site of photosynthesis
What is the spongy mesophyll?
photosynthetic cells below the palisade layer; it has fewer chloroplasts and has many air spaces
What is the lower epidermis?
it is the outer layer of the cells on the lower surface or the underside of the leaf; contains the stomatal apparatus for gas exchange
What the stomatal apparatus or stomata?
it consists of two guard cells and stomatal pore; functions in gas exchange
What are veins or vascular bundles?
they form part of conducting and supporting tissue of the leaf, it consists of the xylem and phloem and supportive cells
what is the function for the air spaces within the spongy mesophyll?
it makes sure that the plant is ready for gas exchange because the co2 will be starved during photosynthesis and oxygen will be high
Why are there more stomata on the lower epidermis than the higher?
because then they will open as a result of the sunlight dehydrating the leaves from moisture and cause the plant to dry up
Describe the a.thaliana experiment goals?
the whole purpose of it was to see how nutrient deficits in plants could cause changes in root morphology by depriving a set of experimental a.thaliana seedlings of phosphorus and seeing how it grew. It shows that a phosphorous deficit lead to shorter length of root length
