Ch8 Cell Diversity Flashcards
Biological organisation
Cell - tissue - organ - organ system - organism
Blood cell - blood - heart - circulatory system - human
Tissue
A group of similar cells that are modified to carry out the same function
-structure of the tissue depends on the type of tissue
-simple tissue has one cell type
-complex tissue has multiple cell types
Four main types of plant tissue
- Dermal
- Vascular
- Ground (bulk of the plant)
- Meristematic (undergo mitosis)
Dermal tissue
Single layer of cells surrounding parts of the plant
Dermal tissue
Location
Description
Function
Location: covering leaves, stems, roots
Description: -often slightly thickened cell wall
- sometimes has a waterproof layer (cuticle) on outer surface
Function: to protect the plant
Vascular tissue
Transports materials around the plant
-two types of cells - xylem, phloem
They are dead cells
Xylem description function
Description: hollow tubes, with openings called pits, that run from roots to leaves
Function: transports water and dissolved minerals
Provides support
Animal tissue four main types
- Epithelial (lines organs and internal cavities)
- Connective (matrix- blood+bone)
- Muscular (contract)
- Nervous
Connective tissue
A number of cells spread out in a material that is produced by the connective cells
Connective tissue function and examples
Joins and supports other body structures
Egs. Adipose tissue(stores fat), cartilage, bone, blood (blood cells suspended in plasma)
Nervoustissue
Composed of neurons
Nervous
Composed of nervous cells
Function of nervous tissue
Carry electrical impulses to and from the brain and spinal cord
Organ
A structure composed of a number of tissues working together to carry out one or more functions
Plant organs
Root
Stem
Seed
Fruit
Leaves
Animal organs
Stomach
Brain
Heart
Lungs
Liver
Organ systems
Consists of a number of organs working together to carry out one or more functions
Animal organ systems
Skeletal
Muscular
Digestive
Epithelial
Circulatory
Respiratory
Urinary
Nervous
Endocrine
Reproductive
Tissue culture
The growth of cells in or on a sterile nutrient medium outside an organism
In vitro
Growing cells outside the body
Explain tissue culture
- Tissue sample is removed from an organism and grown in glassware or a bioreactor, under controlled conditions.
- Often cells are grown in a bath of sterile, nutrient medium
-hormones may be added to improve growth
-antibiotics may be added to kill microorganisms
Applications of tissue culture
Plant breeding
Cancer research
Skin grafts
Micropropagation
The growth of hundreds of plants from small plant pieces
Plant breeding
-Micropropagation
-plant cells are grown on a suitable medium until they form a callus (clump of cells)
-growing conditions are changed to allow callus to become a plant
Benefits of plant breeding
-large number of plants produced on a short time
-all plants are genetically identical
-inexpensive
Skin grafts
Tissue culture used to grow new skin for burn patients
-stem cells- usually from bone marrow- used to grow skin
Benefits of skin grafts
-no need to remove skin from elsewhere in the body
-New skin is not rejected by the patients body as it has been grown from their own cells
Cancer research
- cancer cells produce proteins (antigens) that aren’t present in normal cells
- using tissue culture, it is possible to produce antibodies (from white blood cells) that will react with antigens on cancer cells
Benefits of cancer research (MABS)
- can be attached to toxic drugs to deliver the drug to cancer cells only.
- can be used to test if a sample of cells is cancerous, as they can change colours when bound in antigens
