Biology topics 1 and 2 Flashcards
State the seven characteristics of life.
M.R.S.G.R.E.N: Movement, Respiration, Sensitivity, Growth, Reproduction, Excretion, Nutrition.
What is movement?
A change in position/place.
What is sensitivity?
The ability to detect (sense) and respond to changes in the environment + changes in the body.
What is respiration?
A series of chemical reactions inside organelles called mitochondria which break down nutrient molecules to release energy.
What is growth?
A permanent increase in size of an organism.
What is reproduction?
Producing offspring by fertilization or cell cloning.
What is excretion?
The removal of toxic/waste substances from the body. Also includes excess, more than the body needs.
What is nutrition?
Necessary materials required in the body for growth, development and repair.
Give an example of nutrition needed by plants and nutrition needed by humans.
Plants: Light, CO2, water, iron, magnesium
Animals: Carbohydrates, Proteins, iron, sodium, water.
Give an example of a substance which is excreted from the human body.
CO2
State the structure of an animal cell.
Nucleus, Mitochondria, Cytoplasm, Cell membrane, Ribosomes, Endoplasmic Reticulum.
State the structure of a plant cell.
Nucleus, Mitochondria, Cytoplasm, Cell membrane, Ribosomes, Endoplasmic Reticulum, Vacuole, Chloroplasts, Cell wall.
What is the function of the cell wall?
The cell wall is made from cellulose, gives the cell support, defines shape, prevents bursting.
What is the function of the vacuole?
Contains cell sap, used for storage of materials + support shape of cell. Not enough Cell sap, plant may wilt.
What is the function of the chloroplasts?
Contain green pigment called chlorophyll which absorbs light energy for photosynthesis.
What is the function of the nucleus?
Contains genetic material in the chromosomes. Controls how cell grows, works + cell division.
What is the function of the ribosomes?
Joins amino acids together to make polypeptides.
What is the function of the Endoplasmic Reticulum?
Fold the chains made by the ribosomes to build proteins.
What are specialized cells?
Cells which have special features, allowing them to carry out their jobs.
Give examples of specialized cells.
Palisade mesophyll cell , Red blood cell, Ciliated cell, Sperm and Egg cells, Root hair cell.
How are Palisade mesophyll cells specialized?
- Lots of chloroplasts - more photosynthesis
- Large vacuole - push chloroplasts closer to edge.
- Cylindrical shape - compact
How are Red blood cells specialized?
Biconcave shape - Larger surface area
No nucleus - more haemoglobin to bind to more oxygen
How are Root hair cells specialized?
Large protrusion - larger surface area
No chloroplasts - UNDERGROUND!
Lots of mitichondria - more energy to absorb more minerals
Large vacuole
How are Ciliated cells specialized?
Goblet cells - Produce mucus which traps foreign substances.
Hairs called cilia which sweep mucus out.
Lots of mitochondria - more energy to move cilia.