Plant Anatomy and Physiology

Morphology

Study of the physical form and external structure.

Anatomy

Study of the structures.

Angiosperm

Plants that produce flowers/fruits that facilitate reproduction.

Monocot

Seeds with one cotyledon and one initial leaf.

Dicot

Seeds with two cotyledons and two initial leaves.

Shoot System

The above-ground portion of a plant body, consisting of stems, leaves, and (in angiosperms) flowers.

Root System

All of a plant's roots that anchor it in the soil, absorb and transport minerals (ions), phosphates, nitrates, and water, and also store food.

Dermal Tissue

Outer protective layer that prevents water loss and against damage. Also found within plant protecting the pericycle and vascular bundles (endodermis).

Vascular Tissue

Framework/shape of the leaf
Made up of xylem and phloem
transports water and minerals (xylem) and products of
photosynthesis (phloem)
Hydrates plant
cools plant
Reinforces shape of the plant through turgor pressure

Ground Tissue

Stores stuff, performs metabolic reactions, photosynthesis, structure of plant.

Parenchyma cells (Ground T.)

Perform metabolic reactions
Flexible, single cell wall --> facilitates expansion
Storage of macromolecules (e.g. starch)

Collenchyma (Ground T.)

Supportive cells that has ability to stretch as plant grows.

Sclerenchyma (Ground T.)

Structural cells who are dead at maturity. Secondary cell wall is fortified by lignin (woody tissue).

Xylem (dead vascular tissue)

Transports water and minerals from roots to leaves. Supplies minerals and cools plant.
Made up of tracheids and vessel elements in angiosperms.

Tracheids (in gymnosperms and angiosperms)

Longer, thinner structures for water flow. They have pits in cell wall that improve water flow. Dead at maturity.

Vessel Elements (angiosperms)

Wide diameter with secondary wall supported by lignin. Have a perforated end to improve water flow.

Phloem (living vascular tissue)

Transports macromolecules and products of photosynthesis (ions, G3P, vitamins, proteins, carbs…) from leaves (source) to where it is stored/used (sink). Made up of sieve tubes and companion cells.

Sieve Tubes

Functionally dead, lacking ribosomes, vacuoles, nucleus, cytoplasm. They are the vessels that carry the sap anywhere it is needed in the plant. They have a perforated end (sieve plate) to improve flow.

Companion cells

living parenchyma cells that move items in and out of the sieve tubes and perform metabolic reactions for them. Coupled transport is utilized here to pun macromolecules across their membrane into the tubes, creating a hydrogen gradient in the companion cells and a high osmotic solute concentration within the tubes.

Meristomatic Tissue

Plant stem cells that are involved in growth/repair

Apical Meristomatic Tissue

Located in tips of roots/shoots/axillary buds. Allow plant to grow up and down.

Lateral Meristomatic Tissue

Located along length of roots and stems allowing for growth in diameter in dicots.
Examples: Vascular/Cork Cambium

Protoderm

Meristomatic tissue that produces dermal tissue

Procambium

Meristomatic tissue that produces vascular tissue

Ground Meristem

Meristomatic tissue that creates ground tissue cells

Root Cap

Covering at tip of root that protect the apical meristem as root pushes deeper into soil during primary growth. It also stabilizes the plant, facilitating the absorption of more water and minerals.

Zone of Cell Division (root)

Includes the root apical meristem and its derivates. New root cells are produced here and they are going through the cellular cycle. Allows for increase in plant height/depth.

Zone of Elongation (Root)

Where most growth occurs as root cells elongate. Newly produced cells are in G₁ and they extend cell membrane/wall --> need lost of phospholipids and cellulose from photosynthetic products.

Zone of Maturation (Root)

Where cells complete their differentiation and become distinct cell types.

Terminal Bud (Shoots)

Located at top of plant shoots for upward growth. Composed of apical meristem.

Axillary Bud (Shoots)

Located at sides of Shoot System for outward growth. Made of apical meristem. Branching.

Vascular Cambium

Produces secondary xylem that will take old xylems place in regards to function. Old xylem becomes nonfunctional and sills in.

Cork Cambium (Bark)

Produces a thick, tough, protective covering for plant stems/roots replacing the dermal tissue.

Bark

Outer layer of tree

Wood

Contains tracheids, vessels, and fibers (xylem is lignified).

Heart Wood

Has secondary xylem that is old and nonfunctioning that will eventually fill in as the tree ages.

Sapwood

Functioning secondary xylem

Transpiration

The pull of water and minerals from the roots to the leaves where it will evaporate, creating a water potential gradient and root pressure to bring more water and minerals up.

Root Hairs

increase surface area for water absorption in roots

Aquaporins

Passageways within the membranes that increase the amount of water uptake

Apoplast

Anything outside of cell membrane.
Pathway that most water goes through quickly until it reaches the Caspirian Strip within endodermis (forces water to then take symplast pathway).

Symplast

Anything within the cell membrane including the plasmodesmata. Water will take this pathway into the stele (vascular tissue) of the xylem once it reaches the endodermis.

Properties of Water

Adhesion: Water --> vessel wall
Cohesion: Water molecule --> water molecule
Universal Solvent

Water Potential

Water moves to where the solute concentration in higher (from low to high) --> moves to where it is more negative.

Translocation

Movement of the products of photosynthesis (macromolecules, sucrose/maltose/lactose, ions, vitamins, hormones) form the source (where it is made) to the sink (where it is stored/used).

Source

Where sugar is made:
mesophyll cells of leaf (palisade)
stem (some photosynthesis, storage of polysaccharide)
root
bulb (releases starch in spring)

Sink

Where sugar is stored/used:
roots (growth/storage)
fruit (storage)
buds (growth of new leaves)
stem (growth in height)

Annual

Complete life cycle in one year and dies

Biennial

Plant lives two years and dies

Perennial

Plant lives for many year until destroyed

Stamen

Male
Include:
Anther: pollen receptacle
Filament: structure for anther

Carpel

Female
Include:
Stigma: area for pollen to land
Style: tube/passageway
Ovary

Sporophyte

Diploid (2N)
Mature flowering plant

Gametophyte

Haploid (N) --> one copy
Embryo sac (female) or pollen grain (male)

Male Gametophyte - Pollen Grain

Location: inside sporangium of the anther

Microsporocyte (Male)

Precursor cells that undergo meiosis, forming 4 haploid microspores.

Microspores (Male)

Each will undergo mitosis ONE time, creating pollen grain comprised of 1 generative cell and 1 tube cell per microspore (total of 8 cells now).

Pollen Grain (Male)

Immature gametophyte that becomes mature when generative cell divides into 2 sperm cells (occurs after pollination) via mitosis.

Mature Male Gametophyte

Contains 2 sperma and a tube cell

Female Gametophyte - Embryo Sac

Location: inside sporangium of ovule within ovary

Megasporocyte

Divides by meiosis into 4 cells --> only one will move onto next phase (1 haploid cell)

Megaspore

Divides by mitosis 3 times, creating 8 haploid nuclei. Membranes will then partition this off, creating the embryo sac.

Embryo Sac - Female Gametophyte

1 egg cell (female gametophyte) --> combines with
1st sperm, forming zygote
2 synergids at one end --> lead tube cell into place
for fertilization
3 antipodal cells at opposite end --> no function,
degenerate
2 polar nuclei --> combines with second sperm,
forming endosperm that produces nutrients for
developing embryo

Double Fertilization

1 sperm + 1 egg = zygote
1 sperm + 2 polar nuclei = endosperm

Basal Cells

Forms thread of cells called suspensor that anchors embryo and transports nutrients form parent plant to new plant

Terminal Cell

Gives rise to embryo