Layer C, Task 4 Flashcards
Specialized cells
Cells that perform a specific function (all multicellular organisms are made mostly of specialized cells)
Difference between single-celled organisms and specialized cells
- Single-celled organisms function independently
- Specialized cells cannot survive on their own
4 specialized cells in animals
- Red blood cells
- White blood cells
- Skin cells
- Bone cells
- Muscle cells
- Sperm cells
- Fat cells
- Nerve cells
- Photophores
4 specialized cells in plants
- Cells that transport water & dissolved minerals
- Storage cells
- Photosynthetic cells
- Cells that transport dissolved sugars
- Epidermal cells
- Guard cells
Hierarchy
Organizational structure –> most complex at the top and least complex at the bottom
Hierarchy within animals
Organism level
Organ system level
Organ level
Tissue level
Cellular level
Tissue, organ and organ system
Tissue: Collection of similar cells that perform a function
Organ: Made up of 2 or more types of tissues
Organ system: System of 1 or more organs that work together to perform a body function
4 major types of tissues
- Epithelial tissue
- Connective tissue
- Muscle tissue
- Nerve tissue
Epithelial tissue
Cover surfaces and line internal organs
Function: Protect from dehydration
Connective tissue
Cells and fibres held together by a matrix
Function: Support and insulation
Muscle tissue
Muscle fibres that contain specialized proteins capable of shortening/contracting
Function: Movement
Nerve tissue
Long thin cells with fine branches at the end that conduct electrical impulses
Function: Sensory, communication and coordination within body
Cellular differentation
The process by which a cell becomes specialized
All multicellular organisms start as a single cell (zygote) and as the cells of the embryo continue to divide, they become specialized
Stem cell
Undifferentiated cell that can divide to form specialized cells
A stem cell divides into…
2 daughter cells
Each daughter cell can develop into a different type of cell (based on which parts of its DNA are switched on)
2 types of stem cells
Embryonic stem cells (pluripotent)
Tissue stem cells (multipotent)
Embryonic stem cells
Can differentiate into any kind of cell
Tissue stem cells
Exist within specialized tissue and can only differentiate into certain types of cells
What 2 obvious distinguishing features do plants have
- Green (caused by chlorophyll)
- Cannot move (have structures—usually roots—to anchor them)
A typical flowering plant has 2 body systems:
- Root system
- Shoot system
Root system
- Anchors the plant
- Absorbs water & minerals and stores food
Shoot system
Conducts photosynthesis and produces flowers for sexual reproduction
Leaf
Performs photosynthesis (tissues in the leaf use CO2, water and light energy to produce glucose and oxygen)
Flower
Structure developed for sexual reproduction
Male reproductive structures produce pollen grains
Female reproductive structures produce eggs (after pollination, produce seeds often contained within a fruit)
