B2 Characteristics of Living Organisms, Levels of Organisation, Cell Structure T2-4 Flashcards
cvvAll living things do…
MRS C GREN
MRS C GREN
Movement - growth response/movement of the whole organism
Respiration - produces ATP (molecule that gives energy to cells)
Sensitivity - detecting changes in the surroundings
Control - making sure temperature, pH and chemical composition remains constant
Growth - increase in cell number
Reproduction - producing offspring
Excretion - getting rid of waste products
Nutrition - taking in and using food (feeding and eating)
Examples of how humans carry out MRS C GREN
Movement - muscle contractions in running
Respiration - reaction that takes place in mitochondria which releases energy
Sensitivity - light (seeing), sound (hearing)
Control - sweat (controling body temp by cooling when hot)
Growth - increase in cell number
Reproduction - sperm and egg fuse in fertilisation + foetus grows in uterus
Excretion - get rid of carbon dioxide
Nutrition - we eat food and gain vitamins
Levels of Organisation - smallest to largest
organelle
cell
tissue
organ
organ system
What are the levels of organisation
organelle - part of a cell that carries out a specific function e.g. nucleus, chloroplasts, cell membrane
cell - smallest unit of living things e.g. red blood cells
tissue - groups of cells that have a similar shape, working together to carry out a fucntion e.g. muscles
organ - sveral different types of tissure working together to carry out a similar function e.g. heart, lungs, kidneys
organ system - group of organs with related functions working together e.g. circulatory, digestive, respiratory
Organelles just in plant cells
- chloroplasts
- vacuole
- cell wall
Organells in both animal and plant
- nucleus
- cell membrane
- cytoplasm
- ribosomes
- mitochondria
Describe what the nucleus does
controls the cell - growth and reproduction
Describe what the cytoplasm does
where chemical reactions take place
Describe what the cell membrane does
controls what enters and leaves the cell
(thin semi-permeable membrane)
Describe what the cell wall does
gives structual support and is made of cellulose
Describe what the chloroplast does
site of photosynthesis - absorbs light
(has green chlorophyll)
Describe what the vacuole does
stores cell sap to strengthen cell
Describe what the mitochondria do
site of aerobic respiration -> providing energy for cell
Describe what the ribosomes do
where protein synthesis happens
What are stem cells?
a cell that hasn’t become a specialised cell
Define differentiation
a cell specialises to carry out a specific function
How do specialised cells differ to stem cells?
specialised cells have different shapes of organells and carry out a specific function
Describe how stem cells can potentially treat diseases
- remove stem cells from patient
- treat with cemicals to stimulate differentistion
- inject back into patients
Describe how stem cells can potentially treat diseases
- remove stem cells from patient
- treat with cemicals to stimulate differentistion
- inject back into patients
Where are stem cells found in the human body
- bone marrow
- brain
Conditions that can be treated using stem cells
- anaemia
- stroke
- muscular dystrophy
*** brain injury/Alzeihmers - neural cells - spinal cord injury - nerve cells**
Risks
- may have mutations - not always successful
- may be infected with virus
- stem cells could continue to divide and not differentiate, could become cancerous
Where stem cells can be found
- unused embryos - can produce any cell type - ethical issues over using 3-4 day embryos
- adult - body less likely to reject, no ethical issues - not all cell types can be produced
