Lab 4 Angiosperm Pt 1 Flashcards
Does the Pelargonium display alternate leaf arrangement or opposite leaf arrangement?
- This is the smaller one*
It has alternate leaf
Does the Coleus display alternate leaf arrangement or opposite leaf arrangement?
- This is the larger one*
This has opposite leaf arrangement.
The location of the stem where the leaf attaches is called the?
Node.
The location of the stem that exists between two nodes is called the?
The internode.
What is the difference between the node and the axillary bud?
A node is where leaves, branches, or buds grow on a stem, while an axillary bud is a small bud found between the leaf and stem.
What two things compose a leaf?
- The blade or blades = these are the green parts.
- The petiole = this is the stalk that attaches the blades to the stem.
What does it mean for a leaf to be simple?
It means that the leaf has a single blade.
What does it mean for a leaf to be compound?
It means that the leaf has two or more blades.
What type of leaf venation do most monocots have?
Explain this type.
Parallel
Runs all the same way from the bottom of the leaf.
What are the two types of leaf venation that dicots can have?
Explain what the two types are.
- Pinnate
This consists of a central pin-like vein with adjacent veins coming out at a somewhat perpendicular angle.
- Palmate
This is when there are multiple central veins that all originate from a central point. It branches like the lines in your palm.
What does it mean for a leaf to be pinnately compound?
This means that there are more than two leaves and they are arranged at a more macro-level like the pinnate type of venation.
What does it mean for a leaf to be palmately compound?
This means that there are more than two eaves and they are arranged at a more macro-level like the palmate type of venation.
In reference to the woody twig, describe the terminal bud.
What about the bud scales of the terminal bud?
The terminal bud is the crown-looking thing that we see at the top of the twig.
The bud scales of the terminal bud are the scale-like things that protect the terminal bud and are best seen at the bottom of the terminal bud.
Describe the leaf scars and the structure that exists above them on the woody twig that we looked at.
The leaf scars are essentially what we think of when we think of nodes.
They are what is left over once the leaf has fell.
The structure that we see above the leaf scar is called the axillary bud - this can become a new leaf.
Describe where the lenticels of the woody twig are.
What is the function of this structure?
They are little openings seen as almost dots on the bottom or younger part of the stem.
The lenticels facilitate gas exchange from the environment to the interior tissue.
Describe the terminal bud scale scars on the woody twig that we looked at.
What do they indicate?
They are the rough wraps that we see near the base of where the original stem split.
They indicate where the terminal bud was at the end of the previous growing season.
What is the function of the axillary buds?
This is the bud that is responsible for the new shoots and leaves.
In reference to the woody stem aka (horse chestnut), what was the leaf arrangement?
It was certainly opposite.
We could see that there were nodes on either side right across from each other.
We looked at one l.s. of a stem (Coleus). Be able to label the following with descriptions.
- Apical Meristem - (red head)
- Leaf primordium - (small wings and big wings) will become leaf
- Bud primordium - previous to the axillary bud - (little heads)
- Epidermis - one cell layer around everything
- Vascular Tissue - still developing but seen as darker on the sides of the more immature leaves.
- Parenchyma - literally the bulk of the tissue that will eventually surround all the vascular tissue and make up the pith.
Look at the sunflower stem cross section.
Identify and describe each of the following on the photo.
- Parenchyma - this is the bulk of the tissue in the middle
- Vascular Bundles - these are distinct layers of tissue that can be seen in a ring around the outside.
- Primary xylem - this includes both the vessel elements (which can be seen as the clear circles with pink outline) and the tracheids which are not easily seen.
- Primary Phloem - this is the lighter blue stain that we can see and they contain both sieve tube members and companion cells (better seen in the corn of the monocots)
- Sclerenchyma - these are the small red dots that make up the bundle cap and we called them the phloem fibers.
- Collenchyma - this is the tissue that exists between the epidermis and the rest of the stem. You can see how the shape of the cells changes from the single layer epidermis to the collenchyma.
How was the corn monocot stem different from the dicot sunflower stem?
- The vascular bundles were dispersed everywhere
- The sieve tube members and the companion cells of the primary phloem were much easier to see.
In the corn root longitudinal section, what is the difference between the apical meristem and the root cap?
The apical meristem is not the furthest point and it was stained pretty red likely because there is a bunch of nuclei there.
The root cap was the furthest point and was stained blue because there isn’t a whole lot of division going on there.
What are three “zones” that we referenced in lab?
Which one had the most mitosis going on?
- Zone of Division
- Zone of elongation
- Zone of cell differentiation
the zone of division definitely did
In which zone did we see the root hairs developing?
in the zone of differentiation
Are root hairs extensions of the epidermal cells or are they their own type of cells?
They are lateral extensions.
What is the difference between the root apical meristem and the shoot apical meristem?
The root apical meristem is covered by the root cap, whereas the shoot apical meristem is not and is free.
When we looked at a cross section of some dicot leaves (lilac leaf) identify and describe the various locations of the following structure.
- Upper epidermis - this is the side that contains the thick packed cells with all the chloroplasts.
- Lower epidermis - this is the side that is going to have the most stomates and guard cells and can be easily identified because it is the side that is closest to the air spaces that exist there.
- Palisade mesophyll - tissue layer that is closest to the upper epidermis
- Spongy mesophyll - tissue layer that is closest to the lower epidermis
- Vascular bundles - seem right in the middle and have both primary xylem and phloem.
What is primary growth?
What type of meristem is responsible?
Primary growth is growth in length
Apical meristems are responsible
What is secondary growth?
What type of meristem is responsible?
Growth in width or girth
Lateral meristems are responsible
What are the two ways to determine the age of a woody twig?
- Count the bud scale scars (these cover the axillary buds in winter)
- Cut open the twig and look at the rings of annual growth (secondary growth)
How does primary xylem and phloem differ in the composition of their cell walls as well as the types of cells they have?
Xylem has highly lignified cell walls and the cells are really dead at maturity. Including Tracheids and Vessel Elements
Phloem is not lignified in its cell walls and its cells are the sieve tube members and the companion cells.
How do monocot and dicot leaves differ externally?
Monocot leaves have parallel venation.
Dicot leaves have netted venation
What are three differences between the sunflower stem x.s and the basswood stem x.s that we saw last week?
- Sunflower only has primary growth
- The vascular tissue is not continuous in the sunflower, whereas with the secondary growth that is present in the basswood, we see continuous vascular tissue around the pith
- Sunflower has no vascular cambium - no bark.
