Bio 2 Lab 3 Quiz

From the slides + google

Describe a Phylogenetic Tree

• AKA an evolutionary tree

• Branching diagram that shows the inferred evolutionary relationships amongst various biological species or other entities called their phylogeny

• Based on similarities and differences in their physical or genetic characteristics

• Branches represent a lineage whilst nodes represent the most recent common ancestor of all branches diverging from that node

• A root represents the most recent common ancestor of all taxa included in the tree

• Taxa on branches that diverge from a recent node are more closely related than to taxa on more distance nodes

Palmate vs Pinnate

• Pinnate: A feather-like with structures that branch off a single axis.

• Palmate: A hand-like where several veins or leaflets radiate outward from a central point.

Leaf vs Leaflet

• Leaf: Complete plant organ that is independent and attaches to a stem at a node

• Leaflet: Segment of a larger compound leaf in which several leaflets make up a single leaf. Part of compound leaves and doubly compounded leaves whose axillary buds tend to be larger than those of normally compound leaves.

Venation

• The arrangement of vascular bundles aka VEINS across the blade of a leaf.

• Provides a skeletal framework for the leaf and distributes water/nutrients throughout the lamina.

Xylem

• A type of vascular tissue that controls the transport of water and dissolved minerals.

• Goes from the roots to the stem and leaves also gives support to the leaf’s veins.

Phloem

• A vascular tissue that transports sugars and organic compounds synthesized during photosynthesis.

• Moves nutrients from the leaves to the rest of the plant for growth or storage.

Stomata

• Small pores that are regulated and primarily located on the lower epidermis.

• Surrounded by guard cells that will inevitably swell or shrink to open or close the pore.

• This is how gas exchange and transpiration can be managed.

Spongy Mesophyll

• Beneath the palisade layer.

• Loosely packed and irregularly shaped cells with a lot of space between them which can freely exchange gases needed for photosynthesis as well as respiration.

Palisade Mesophyll

• Primary photosynthesis site.

• Tightly packed and column-shaped cells beneath the upper epidermis.

• Packed with chloroplasts for MAX sunlight.

Cuticle

• A waxy layer over the epidermis

• Secreted by epidermal cells

• Minimizes water loss through evaporation

Epidermis

• The outermost layer of cells covering the upper and lower surfaces of the leaf

• Only a single-layer of cells

• Physical shield against pathogens, environmental stressors, and predators

Anatomy of Root Plants includes what characteristics?

• Primary growth

• Secondary growth

• Stems

• Roots

• Root hairs

Anatomy of Growth in Plants

• Primary growth increases length via the apical meristems which are the trips of roots/shoots

• Secondary growth increases diameter via the cambium (either the vascular or the cork) along stems/roots where the xylem grows inward from the cambium and the phloem groward outward

• Monocot stems have vascular bundles scattered throughout whilst eudicots have rings of vascular bundles around the pith

• In monocots, the roots have a ring of vascular bundles surrounding the pith whilst the roots of eudicots have a xylem center surrounded by phloem

• Root hairs are extensions of root epidermal cells that increase root surface area for absorption of water and nutrients and interact with soil microorganisms

What are the 3 main Angiosperm Clades?

• Magnoliids

• Monoco

• Eudicots

Magnoliids

• Two cotyledons

• Reticulate venation — the veins in the leaves form a net-like branching pattern where the main central vein runs up the middle with smaller veins webbed across the surface

• Vascular bundles in rings

• Parts in 3s or numerous

• Taproots common — the plant grows into a single, thick main root that drills straight down deep into the soil

• Pollen monosulcate — each grain has a single, linear furrow or groove on its outer surface which is an exit point for the pollen tube to grow out to fertilize the plant’s ovary

Monocots

• One cotyledon

• Parallel venation — an arrangement of veins in a leaf where the veins run parallel to each other across the entire length or width of the leaf blade

• Scattered vascular bundles in rings

• Floral parts in 3s

• Adventitious roots

• Pollen monosulcate — a type of pollen grain characterized by a single, elongared furrow known as a sulcus located on the distal face

Eudicots

• Two cotyledones

• Reticulate venation

• Vascular bundles in rings

• Floral parts in 4s or 5s

• Taproots common

• Pollen tricopate — pollen grains that have exactly three germinal furrows called colpi

Angiosperm Life Cycle

• Follows the alternation of generations

• Sporophyte dominant

• The gametophyte is greatly reduced; the males are pollen which are incredibly small and the females are the embryo sacs which are also small

• Double fertilized meaning that one sperm fertilizes an egg cell to create the diploid embryo whilst a second one fuses with two polar nuclei to form a triploid nutrient tissue called the endosperm

Basic Flower Anatomy includes …

• Stamen

• Anther

• Filament

• Petal

• Sepal

• Carpel

• Stigma

• Style

• Ovary

• Ovule

Ovule vs Ovary

• Ovule: The egg-like structure housed inside the ovary that after fertilization turns into a see

• Ovary: The swollen, enlarged base of the carpel containing the ovules that once fertilized, the ovary develops into a fruit

Style vs Stigma

• Style: The slender, tube-like stalk that connects the stigma to the ovary

• Stigma: The sticky, receptive tip of the carpel designed to catch pollen

Petal vs Sepal

• Petal: The colorful and showy modified leaves that surround the reproductive organs whose main purpose is to attract pollinators

• Sepal: The leaf-like structures that are usually green and located at the base of the flower that encloses and protects the delicate flower bud before it opens

Stamen, Anther, and Filament

• Stamen: The overall male reproductive structure of the flower

• Anther: The pollen-producing tip of the stamen

• Filament: The slender stalk that supports and elevates the anther

Phylum Anthophyta (“Angiosperm”)

• Very successful group with over 290k species (80-90% of all plant species)

• Coevolved with pollinators as they diversified in tandem with insects

• Developed nectar production and unique flower shapes to attract specific pollinators, ensuring that pollen is transferred to a plant of the same species

• Pollination “syndromes” refers to the flower traits that plants evolved to attract specific pollinators that could have evolved morphologically, visually, or olfactorily

• Not all flowers are pollinated by insects; other pollinators include bats, hummingbirds, moths, and even more!

• Has flowers and fruits but no antheridia or archegonia

• The ovules are enclosed within not one but TWO integuments and a carpel wall

• Gametophytes are incredibly small with only a few cells in them

• Immotile sperm which are carried to the ovule by the pollen tube and aren’t flagellated

Storage Organs Activity

• Sweet Potato - modified root

• White Potato - modified stem

• Carrot - modified tap root

• Onion - modified leaves

• Celery - modified leaf petiole