Biology - Cell Diversity

Tissue

a group of similar cells that carry out the same function

Plant tissues

dermal, vascular, ground, meristematic

Animal Tissues

connective, muscular, nervous

Dermal tissue location

Covering leaves, stems and roots

Dermal tissue function

protects the plant

dermal tissue adaption

have a thickened cell wall

types of vascualr tissue

xylem and phloem

xylem function

transports water and minerals through the plant, provides support

xylem adaption

narrow, has pits and is reinforced by lignin

phloem function

transports food from the leaves to other parts of the plant

phloem adaption

contains a companion cell which contains many mitochondria

connective tissue function

joins and supports other body structures eg. blood

nervous tissue composition

composed of nerve cells called neurons

nervous tissue function

neurons carry electrical impulses to and from the brain and spinal cord

nervous tissue adaption

myelin sheath helps insulate the movement of the electrical impulse

muscle tissue function

allows movement by contracting and relaxing

muscle tissue adaption

By their cells having larger amounts of mitochondria to provide the necessary energy required

tissue culture

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

in vitro growth

growth of cells outside an environment

in vivo growth

growth of cells inside the body

factors that allow successful tissue culture

correct nutrients, oxygen supply, sterile environment

what can harm tissue culture

other micro organisms growing in the tissue culture, unwanted waste and bacteria will kill the cells

Applications of tissue culture

Micropropagation, cancer research, skin grafts

Micropropagation

The growth of large numbers of plants from very small plant pieces

how micropropogation works

small number of cells grown in a culture and form a callus, these cells divide by mitosis

benefits of micropropogation

large number of plants produced quickly, plants are all genetically identical, cheaper

skin grafts

used to grow new skin on bad skin burns

Benefits of skin grafts

new skin will not be rejected, no need to take skin from other parts of the body

What is an organ?

A group of different tissues that work together to perform a certain function.

Examples of plant organs

stems, roots, leaves

Examples of animal organs

heart

What is an organ system?

two or more organs working together to carry out one or more functions

examples of organ systems

digestive system, respiratory system