health science (Sec 1 Singapore)

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health science (Sec 1 Singapore) by Mind Map: health science (Sec 1 Singapore)

1. cells

1.1. can be deadly

1.1.1. cancer calls

1.2. components of a cell

1.2.1. cell membrane Characteristics Thin layer around cell partially permeable membrane Function to control substances entering and exiting the cell

1.2.2. nucleus Characteristics contains chromosomes which are hereditary materials surrounded by nuclear envelope Functions controls all cell activity

1.2.3. cell wall Characteristics Thick layer around plant cell made up of cellulose fully permeable Functions provides protection against mechanical damage and gives the plant a fixed shape support a plant cell and gives it a regular shape

1.2.4. cytoplasm Characteristics contains water and many other substances important organelles in it jelly like substance that fills the cell Function place where most life proccesses

1.2.5. vacuole Characteristics Fluid filled space enclosed by membrane difference between animal and plant cell Functions Stores water and dissolved substances(e.g. food waste products

1.2.6. Mitonchodrion (plural: mitochondria) Characteristics Small spherical or rod-shaped organelles Functions where respiration take place for release of energy

1.2.7. Chloroplast Characteristics Small disc-shaped  organelles found in plant cells Functions Site where photosynthesis takes place

1.3. Comparison of animal and plant cell

1.3.1. Animal cell absence of cell wall absence of chloroplast Presence of many small temporary vacuoles Absence of starch granule irregular shape

1.3.2. Plant cell Presence of cellulose cell wall Presence of chloroplast Presence of a large central vacuole filled with cell sap Presence of starch granules regular shape

1.4. Specialisation

1.4.1. undergo differentiation when structures are modified to suit specific function performed stem cells can be therapatic Functions Structural adaptation Xylem vessels Functions Structural adaptation Red Blood Cell Functions Structural adaptation Adaptation must fit function

1.5. Levels of organism

1.5.1. cell

1.5.2. tissue Cells of same type grouped together to carry out a special function Examples Epidermal tissue or ephithelium Blood tissue Connective tissue Nervous tissue

1.5.3. organ Different tissues untied to form a special function

1.5.4. organ system several organs working together for a special purpose examples Digestive system Respiratory system Circulatory system Excretory System Nervous system Musculo-skeletal system

1.5.5. organism various organ systems working together constitute an organ

1.6. Division of labour

1.6.1. work is divided cells among various components and organelles of cell Multicellular among each type of cell, tissue and organ

1.6.2. breakdown of work into small and more specific tasks allows the organism to carry out its function more efficiently

1.7. Characteristics of living organisms

1.7.1. ability to move body parts

1.7.2. Intake of food into the body and conversion into new protoplasm

1.7.3. breakdown of food substances to release energy in living cells

1.7.4. Production of new individuals for survival of the species

1.7.5. Permanent increase of size with changes of form and structure

1.7.6. Removal of waste products in living cells

1.7.7. Ability to respond to changes in the environment

1.7.8. ability of species to change to improve its chances of survival

1.8. a basic unit of life

1.9. living matter called protoplasm

1.9.1. 3 parts nucleus cytoplasm plasma membrane

2. Transport in humans

2.1. Need for transport system

2.1.1. Unicellular system example amoeba no part of cell is too far from external environment Exchange of a substance occurs by diffusion Oxygen and nutrients reach all part of cells Waste products diffuse out of cell Transport system not needed

2.1.2. Multicellular example human Cells far from external environment Diffusion is too slow to bring oxygen and nutrients to cell or remove waste products from cell Transport system needed

2.1.3. continue from here