Plant Phys lab practical

What is the orange organelle?

The dyed organelle are chromoplasts.

Plastids that contain high concentrations of carotenoid pigments, rather than chlorophyll. Chromoplasts are responsible for the yellow, orange, or red colors of many fruits, flowers, and autumn leaves.

What is the blue organelle

A membrane-bound cellular organelle containing water and dissolved substances such as salts, sugars, enzymes, and amino acids. Vacuoles function in maintaining water balance and cellular turgor. Lytic vacuoles are characterized by a more acidic pH and can often occupy a majority of the space within a cell. Specialized protein storage vacuoles are found primarily in seeds and very young seedlings.

What is the green organelles?

What is name of the cordinated movement of these organelles and why does it occur?

Chloroplasts.

Cytoplasmic streaming: The coordinated movement of particles and organelles through the cytosol. Which can be driven by the interaction with molecular motors associated with the cytoskeleton.

occurs to help the transport of nutrients and organelles

What is the star-like organelle 

Aerenchyma: allows 02 to diffuse down to submerged organs. Anatomical feature of roots found in hypoxic conditions, showing large. Gas-filled intercellular spaces in the root cortex.

What are the three main cell types?

Parenchyma: The organelle that contains the genetic information primarily responsible for regulating cellular metabolism, growth, and differentiation.

Have thin primary cell walls, no secondary cell wall. Have pectin, but not lignin

(dye pink/red)

Collenchyma: A specialized parenchyma with irregularly thickened, pectin-rich, primary cell walls that function in support in growing parts of a stem or leaf.

Unevenly thickened primary cell walls. No secondary cell wall. Provide structure and support. Have pectin. provide structure and support.

(dye pink/red)

Sclerenchyma: Plant tissue composed of cells, often dead at maturity, with thick, lignified secondary cell walls. It functions in support of nongrowing regions of the plant.

Have thin primary cell walls. Have thick secondary cell walls. Have lignin, are super strong and die at maturity. Provide support and structure

(dye blue/green)

What are the cell types shown?

The undyed cells on the right are water storage cells

The left cells are vacuoles 

What are the materials that make up cell walls and what color do they dye

Pectin: stain pink or red

Lignin: stain blue or green

What are the blue bundles in the middle?

what are the green circles?

The blue thing are fibers and are grouped in bundles

The green circles are chloroplasts.

What kind of plastids do you see in the green and red fruits?

In the green fruits chloroplasts would be present for photosynthesis. While chromoplasts would be present for the red fruit.

How do plastids differ in their shape, pigmentation, and size?

Plastids can differ largely in these characteristics because of the different functioning of the many types of plastids. The different types require different traits in order to better help the survival of the plant and allow it to reproduce. Different pigments, organelles and protein composition can effect these traits.

The difference between monocot and dicot leaves.

The mesophyll is differentiated in eudicots and has 1 row of palisade parenchyma, the mesophyll is not differentiated in monocot leaves. This is because monocots are generally more simple in comparison to eudicots. 

Functions for Upper epidermis, stomata, palisade parenchyma, spongey mesophyll and vascular bundles.

Upper epidermis: the outermost layer of plant cells, typically one cell thick.

Stomata: are small openings through which CO2 uptake and the majority of water loss occur.

Palisade parenchyma: Are parenchyma cells below the leafs upper epidermis. The top one to three layers of pillar-shaped photosynthetic cells are palisade cells.

Spongey mesophyll: Cells of irregular shape located below the palisade cells and surrounded by the large spaces

Vascular bundles: Are used for the transport of molecules. They contain the xylem, phloem and may contain cambium cells.

Is this monocot or dicot? Why?

Dicot. One reason is that the vascular bundles are in a ring, not random (like monocot).

What two defining characteristics that distinguish between root stele and shoot stele

The root stele has the casparian strip

(a band of suberin and lignin in the endodermis of plant roots that acts as a selective barrier, forcing water and minerals to pass through the plasma membrane of endodermal cells instead of the cell wall.)

The stem stele lacks an endodermis

What are the functions of these characteristics? Epidermis, cortex, endodermis, pericycle and stele

Epidermis: the outermost layer of plant cells, typically one cell thick. Protects the roots from the environment

Cortex: the outermost layer of the root delimited on the outside by the epidermis and on the inside by the endodermis transporting water and nutrients from the epidermis to the central vascular tissue, storing reserve food like starch and other compounds, and providing physical support to the root.

Endodermis: is a specialized layer of cells with a casparian strip surrounding the vascular tissue in roots and some stems. selectively controls the movement of water and minerals 

Pericycle: are the meristematic cells forming the outermost layer of the vascular cylinder in the stem or root, interior to the endodermis. An internal meristematic tissue from which lateral roots arise. initiate lateral roots, contributing to a more extensive root system, and to participate in secondary growth by forming vascular cambium (for more vascular tissue) and cork cambium

Stele: is the tissues located interior to the endodermis contains the vascular elements of the root. The phloem and the xylem. Used in the transport of water and minerals.

Look at the cross and longitudinal sections.

The four main types of secondary cell wall deposition.

What are tracheids? what are tori and where are they found?

Tracheids: Spindle-shaped, water-conducting cells with tapered ends and pitted walls without perforations found in the xylem of both angiosperms and gymnosperms.

Tori: are central thickening found in the pit membranes of tracheids. They are important in preventing embolisms in conifers.

Tori are found in pit membranes of tracheids in the xylem of gymnosperms.

Why do tracheids differentiate in the spring and late summer months

Tracheids differentiate depending on the season because of different environmental factors. The primary factors is different water availability, the high availability of water in spring causes tugor pressure increase making the cells inflate, increasing their diameter. In later summer there is less water availability causing a decrease in tugor pressure. This results in smaller tracheids in the later months.

Tangential section of conifer wood

What are annual rings?

Annual rings are bands in the cross section representing periodicity in activity of the vascular cambium. These occur due to the different availability of water during the spring and summer seasons. The more water in spring months cause the vascular to grow wider, lighter cells and the lack or water in late summer causes the cells to get smaller and darker. 

microscopic view of bougainvillea bract

microscopic view of epidermal view.

Cork: A part of the secondary dermal system, or periderm, of woody plants, consisting of dead cells with secondary cell walls rich in suberin and lignin. Also called cork. protection, forming a water-resistant and insulating barrier that safeguards internal tissues from damage caused by environmental stressors like drought, pathogens, physical harm, and extreme temperatures.

What molecules do you think give the leaves their red color?

Red chromoplasts that have lycopene a type of carotenoid pigment would result in a red color.

What is the function and location of the cuticle?

The cuticle is a multilayered structure of waxes and related hydrocarbon deposited on the outer cells of the leaf epidermis. The cuticle can reflect light, restrict the diffusion of gasses and prevent the entrance of pathogens. 

What are the functions of trichomes

Trichomes are hair like epidermal cells that keep the leaves cooler by reflecting radiation. They also manually impede insect infestation. The trichomes observed were glandular.

What are these?

They are glandular trichomes

What are these?

They are non-glandular trichomes

Stomatal complex