Chapter 8: Cell Diversity

Tissue

a group of similar cells that are modified to carry out the same function within a multicellular organism

Plant Tissue

dermal, vascular, ground, meristematic

Dermal Tissue

tightly packed epidermis cells that are covered with a wax

Function of Dermal Tissue

protect the plant, cuticle prevents water loss

Location of Dermal Tissue

covering leaves, stems, roots

Herbaceous

non-woody plants

Dermal Tissue in Herbaceous Plants

epidermis

Dermal Tissue in Woody Plants

periderm

Dermal Tissue Adaptation

thickened cell wall

Vascular Tissue

xylem, phloem

Xylem

transports water and dissolved minerals throughout the plant, provides support in woody plants

Phloem

transports food made in the leaves

Animal Tissue

epithelial, connective, muscular, nervous

Connective Tissue

blood, cartilage

Function of Connective Tissue

attaches things together, gives support and makes blood

Connective Tissue Adaptation

cells are spread over a matrix, red blood cells have biconcave shape to facilitate oxygen transport

Muscle Tissue

cardiac muscle, skeletal muscle

Function of Muscle Tissue

produce movement, stabilise joints

Muscle Tissue Adaptation

have many mitochondria, can contract and relax

Nervous Tissue

main component of the nervous system, is composed of neurons

Function of Nervous Tissue

carry messages to and from the brain via the spinal cord in the form of electrical impulses

Nervous Tissue Adaptation

has myelin sheath to insulate impulses

Tissue Culture

the growth of cells in or on a sterile nutrient medium outside of an organism

Sterile

no microorganisms

Aseptic

no unwanted microorganisms

Conditions for Tissue Cultures

temperature and gas concentrations, pH and glucose concentrations, vitamins, minerals, salts, amino acids, and hormones

Applications of Tissue Cultures

skin graft, micropropagation

Skin Graft

stem cells grown at the bottom of a flask, thin sheet of cells transplanted to facilitate repair of skin

Advantages of Skin Grafts

little chance of rejection since cells are genetically identical to recipient

Stem Cells

cells that can develop into any body tissue, found in embryos, umbilical cords, and bone marrow

Pluripotent Cells

stem cells found in embryo

Micropropagation

part of plant is cut into many small pieces and are cultured over time to form a callus

Advantages of Micropropagation

large number of plants in a short space of time, new plants are treated during culture so they are virus free, all plants are genetically identical, inexpensive way to produce similar plants

Organs

a structure composed of a number of tissues that work together to carry out one or more functions

Plant Organs

roots, stem, leaves, flowers, seeds, fruit

Leaf

has dermal, vascular, and ground tissue, responsible for photosynthesis

Animal Organs

heart, skin, liver, stomach

Heart

has muscular, epithelial, connective, and nervous tissue, pumps blood around the body

Organ System

a number of organs working together to carry out one or more functions