Applied Plant Science Exam 1

Cell Wall

Arrangment of Fibrils, Microfibrils, and Cellulose

Cellulose

A chain of glucose monomers

Hemicellulose

Holds cellulose fibrils together

Pectin

Gives stiffness (like in fruit jelly - think fruit snacks)

Glycoprotein

Proteins with associated sugars - extensions

Middle lamella

First produced when new cell walls are formed. Shared by two adjacent cells.

Primary wall

Laid out on either side of middle lamella (flexible)

Plasmodesmata

Communication between cells - Cytoplasmic strands that extend between cells through minute openings

Plastid

double membrane organelles in plants and algal cells

Chloroplast

The most conspicuous plastid, bound by double membrane and contain Grana, Thylakoids, Chlorophyll, Stroma, and small circular DNA molecules

Grana

Made up of Thylakoids

Thylakoid Membrane

Contains the Chlorophyll and the first steps of photosynthesis occur here

Stroma

Matrix of Enzymes involved in photosynthesis

Small circular DNA molecules

Encodes for production of certain proteins for photosynthesis

Chromoplast

Synthesize and accumulate caratenoids that provide color to plant tissues.

Leucoplasts

Colorless plastids that sythensize and store starch (amyloplasts), oils (elaioplasts), and proteins.

Vacuoles

90% of plant cells are taken up by vacuoles, which store nutrients, waste products, and help maintain turgor pressure.

Anthocyanins

water-soluble pigments that contribute to red, purple, and blue colors in plants.

Plant Organs

Structures that perform specific functions, including roots, stems, flowers and leaves, essential for plant growth and development.

Plant Tissues

A group of cells that perform similar functions, each organ is composed of tissue.

Meristematic Tissue (Meristems)

Actively dividing cells, permanent region of growth, Three different kinds apical, lateral, and intercalary

Permanent Tissue

simple and complex cells developed from differentiating meristems

Apical (Apex) Meristems

Produce primary tissues and grow from the tips of roots and shoots (top of plant)

Lateral (Secondary) Meristems

Produce secondary tissues that increase the girth of roots and stems

Vascular Cambium

Produces tissues that function primary in support and conduction

Cork Cambium

Lies outside the vascular cambium just inside the outer bark (Produces Bark)

Intercalary Meristems

These are in the vicinity of nodes (leaf atteachment area) and they add to stem length

Simple Tissues

Produced by Meristems and consist of only ONE kind of cell

Complex Tissues

Produced by Meristems Consist of TWO or MORE kinds of cells

Parenchyma tissue (Simple Tissue)

Alive, thin pliable cell wall, most abundant, used for metabolism and storage.

Collenchyma tissue (Simple Tissue)

Alive, cell wall thick with thickness due to primary cell wall, very strong and pliable

Sclerenchyma tissue (Simple Tissue)

Dead at maturity, Thick tough secondary cell wall and function as support, with two types sclereids and fibers

Sclereids (sclerenchyma tissue)

Stone cell, scattered in tissue, cells as long as wide (defined shape)

Fibers (sclerenchyma tissue)

Dead at maturity, much longer than it is wide and contain lumen (tiny cavity)

Xylem (Complex Tissue)

Cheif conducting tissue for water and mineral that are absorbed by the roots

Phloem (Complex Tissue)

Conducts dissolved foods materials produced by photosynthesis throughout plant

Vessel elements (Xylem Tissues)

Open at ends, dead at maturity, Lay end to end to form vessels with a thick secondary wall

Tracheids (Xylem Tissues)

Tapered at end with pairs of pits that allow water to pass from cell to cell, Dead at maturity, and thick cell wall.

Rays

Lateral conduction of food cells and made up of long lived parenchyma cell

Sieve Tube Members (Phloem Tissues)

Lay end to end to form sieve tube, the ends have sieve plates with small pores, and they lack a nuclei and cell wall

Companion Cells (Phloem Tissues)

Aids in conduction of food and help with STM (Sieve Tube Members)

Sieve Cells

Found in more primitive vascular plants such as Ferns and Gymnosperms

Dermal Tissue (Complex Tissue)

One cell layer thick

Epidermis (Dermal Tissue)

Exterior tissue, generally one cell layer thick covering all plant organs

Cuticle on Stems and Leaves (Dermal Tissue)

Cutin wax is secreted on cuticle, helps prevent water loss, and protect against pathogens

Gaurd Cells and Pores (Stomata, Stoma-Singular) (Dermal Tissue)

There are two Gaurd Cells for every Stomata which regulates the passage of water and atmospheric gasses into and out of the leaf

Trichomes (Dermal Tissue)

Helps reduce evaporation and adds protection to the plant

Root Hairs (Dermal Tissue)

Increases absorbtive area of root surface

Periderm (Dermal Tissue)

Consists of Bark, Cork cells - Dead at maturity - Secretes suberin into walls, Lenticels - gas exchange - breathe

Root Hairs

Epidermal cell extensions, critical for efficient water/mineral uptake, and increase to

Radicle

The start of root system found in the seed

Taproot

Radical may develope into thicker with thinner branch roots (dicotyledonous)

Adventitious Roots

Grows root from leaf or stem and can develop fibrous root system

Fibrous Roots

Large number of fine roots of similair diameter (monocotyledonous)

Root cap

Parenchyma cells covering each root tip, protect tissues from damage as root grows, sicretes mucilage that act as lubricant

Region of Cell Division (Root)

Composed of apical meristems in the center of root tip

Region of Elongation (Root)

Cells become several times their original length

Region of Maturation (Root)

Cells differentiate into various distinctive cell types, root hairs form

Cortex - (Root Structure Region of Maturation)

Parenchyma cells- Mostly stores food

Endodermis (Roots)

Single-layered cylinder of compact cells. Cell walls with casparian strips (regulates water and inerals transport)

Casparian Strips (Roots)

Regulates water and mineral transport.

Pericycle (Roots)

Outer boundray of vascular cylinder, continues to divide, even after mature and forms lateral roots

Vascular Cylinder (Roots)

Consists mainly of Primary Xylem and Primary Phloem but different configuration of cells between Monocots and Dicots