Lab 1 Flashcards
Leaves and Plant Reproduction
Midrib
large bulge in the middle of the leaf which contains a large vein. This midrib vein branches repeatedly into smaller and smaller veins extending throughout the leaf.
Veins
Vascular bundles of the leaf, primarily made up of vascular tissues XYLEM and PHLOEM.
Xylem cells
(stained red), are large empty cells with thick walls.
Phloem cells
(stained green), are smaller and have thinner cell walls.
Bundles Sheath
protective layer of parenchyma cells which typically encloses each vein.
Upper and Lower Epidermis
the outermost layer of the top and the bottom of the leaf respectively. Both layers are one cell thick and normally coated with a very thin waxy cuticle.
Cuticle Layer
waxy layer (thin or thick, transparent). Found above the upper epidermis and or below the lower epidermis.
Stomata
pores (holes) in the upper and or lower epidermis. Surrounded by a pair of guard cells, which can be open or closed to allow for gas exchange.
Hydrophytes
plants adapted to wet environments (hydro=water) (phyte=plant)
Mesophytes
plants adapted to moderate amounts of water in their habitats (meso=middle)
Xerophytes
plants adapted to dry environments (xero=dry)
Mesophyll
sandwiched between the upper and lower epidermis, the photosynthetic tissue that makes up the middle part of the leaf. It is best observed in the regions between the veins. Consists of two tissue types: palisade mesophyll ( or parenchyma) and spongy mesophyll (or parenchyma).
Palisade mesophyll
long rectangular cells filled with chloroplast (photosynthesis)
Spongy mesophyll
Irregular shaped cells, loosely packed (gas exchange).
Vascular bundles
composed of thick walled Xylem cells (transports water and minerals) and smaller thin walled Phloem cells (transports sugars).
Tissue plans
A line drawing to proportion to show the different “layers” of tissue only, without cellular details. Notes are very important, must show all formulas and calculations.
Lengths
- Diameter of field view under low power = 4500µm
- Diameter of field view under medium power = 1800µm
- Diameter of field view under high power = 450µm
Calibrated values for this semester
- Low power objective: 250 µm/od
- Medium power objective: 100 µm/od
- High power objective: 25µm/od
Nerium (xerophyte) internal adaptation to prevent water loss
- Crypts with epidermal hair
- Thickened cuticles on upper and lower epidermis
- Thickened upper epidermis and palisade mesophyll
Sample Calculations: Specimen Length and Specimen Width
Specimen Length: Diameter of field view under high power = 450µm
Specimen Width: Calibrated value for one ocular division for high power objective = 25µm/od = ?µm (value you calculate from the above line) X # of ocular divisions taken up by the specimen’s width #od (value you determine using the ocular ruler).
Scale calculation
Scale = Actual Specimen Length/ Length of Drawing (chosen between 7 and 10cm) = 450µm/*cm = **µm/cm
Drawing width
Drawing width = Actual Specimen Width/ Scale = ?µm/ **µm/cm = —cm
Tissue plan format
Figure 1: Tissue Plan of —–(viewed at—-)
Actual Specimen Length* Actual Specimen Width; Scale
DRAWING
Notes: 3-4 GOOD notes (full complete sentences):
- Drawn from prepared slide of temporary wet mount?
- Describe each layer: shape of cells? How many cells thick?
- Structures expected to see but didn’t?
Complete Flower
4 whorls present
- sepals
- petals
- stamen: anther & filament
- carpel/pistil: stigma, style, ovary & ovules
Incomplete Flower
When any of the whorls are missing
Perfect Flower
- Has both male and female organs
- Stamen: anther & filament
- Carpel/pistil: stigma, style, ovary & ovules
Imperfect Flower
Has either male or female organs. (Imperfect flower = incomplete flower, an incomplete flower can still be perfect).
Gadiolus Flower
- Complete because 4 whorls are present
- Perfect because it has both male & female organs
- 3 parts that make up the female reproductive organ: stigma, style & ovary
- 2 parts that make up the male reproductive organ: anther & filament
Flowering plants
variety of agents but rely on animals and wind for pollination
Animal pollinated flowers
colour, fragrance, flower shape
Wind pollinated flowers
dull colours, plain, reduced scent and nectar, pollen light-weight
Maple Key
dispersed by wind, they have wing-like structures
Fireweed
dispersed by wind, they tend to be feathery and their seeds crack open.
Sticky burrs
Attach to animals by their hooks & barbs, they rely on animals
Apples
By animals, fleshy which entices animals to eat them and release their seeds in faeces
Coconut
Water dispersal, it is very buoyant which allows fruit to float in the sea
Lupine
Seed pods, they burst which allows them to disperse by propulsion
The Fruit
- Two functions: protection and seed dispersal
- Fruit dispersal mechanisms: wind, water, animal, and propulsion
- Reproduces without seeds
- Gives rise to clones
Intro
While plants carry out sexual reproduction through the union of a sperm nucleus (part of a pollen grain) and an egg (enclosed in an ovule in the ovary), many can also reproduce asexually (VEGETATIVE REPRODUCTION)
Vegetative reproduction
involves growth of the plant from specialized structures by mitosis.
Pollination
is the process by which pollen is transferred from male organ of the plant (the anther) to the female organ (the carpel). Most seed plants rely on animals or wind to distribute their pollen. Once the pollen reaches the female organ a pollen tube grows to the ovule allowing FERTILIZATION
Fertilization
the union of the sperm nucleus and the egg. After fertilization has occured, the resulting zygote develops into an embryo.
A seed
Consists of the embryo, a source of stored nutrients (endosperm) and a protective seed coat. While flowering plants are not the only plants that have seeds (gymnosperms such as pine also have seeds), seeds are another reason for the success of angiosperms as seeds are much more resilient than the spores that are found in some plants. Seeds are produced within a FRUIT (a mature ovary).
Daffodil (bulb)
Has fleshy leaves arising from the small stem base
Crocus (corm)
Looks like a bulb but has papery scale-like leaves covering the corm
Potato (tuber)
Has buds/eyes on their surfaces, they are swollen portions of stems
Bulbs
the bulk of a bulb consists of fleshy leaves that arise from a small stem at its base.
Corms
Corms superficially look like bulbs but are composed almost entirely of stem tissue with papery scale-like leaves that cover the corm.
Tubers
Tubers are swollen portions of stem that are usually found underground, as they are stems, they have buds also known as “eyes” on their surfaces. When farmers plant potatoes, they usually plant pieces of cut up potato containing an eye (not seeds). Each “eye” on the tuber has the potential to develop into a new plant.
