Everything we need to know to pass CSEC Flashcards
What are the essential functions performed by all living organisms?
Life Processes
Includes movement, nutrition, respiration, excretion, growth, reproduction, sensitivity, and homeostasis.
Define movement in the context of living organisms.
The ability to change position of the whole body or parts of the body.
What is nutrition?
The process by which organisms obtain and utilize food for energy, growth, and maintenance.
What is respiration?
The biochemical process of releasing energy from organic compounds, especially glucose.
What does excretion refer to in living organisms?
The removal of metabolic waste products from the body.
Define growth in living organisms.
The permanent increase in size, volume, or mass of an organism.
What is reproduction?
The process by which organisms produce offspring of their own kind.
What is sensitivity or irritability in living organisms?
The ability to detect and respond to changes in the internal or external environment.
What is homeostasis?
The maintenance of a relatively stable internal environment despite changes in the external environment.
What does the cell theory state?
- All living organisms are composed of cells
- Cells are the basic structural and functional units of life
- All cells arise from pre-existing cells
What is the function of the cell membrane?
Controls movement of substances into and out of the cell.
Define cytoplasm.
The gel-like substance between the cell membrane and nucleus.
What is the function of the nucleus?
Controls cellular activities and contains genetic information.
What are mitochondria known for?
Site of aerobic respiration; produces ATP (cellular energy).
What is the role of ribosomes?
Site of protein synthesis.
Differentiate between rough ER and smooth ER.
- Rough ER: Contains ribosomes; involved in protein synthesis
- Smooth ER: Lacks ribosomes; involved in lipid synthesis and detoxification
What is the function of the Golgi apparatus?
Modification, packaging, and distribution of proteins and lipids.
Define lysosomes.
Membrane-bound vesicles containing digestive enzymes.
What are vacuoles used for in cells?
Storage of water, nutrients, waste products, and maintaining turgor pressure.
What is a cell wall?
Rigid layer outside the cell membrane providing structural support and protection.
What are chloroplasts responsible for?
Site of photosynthesis.
List the differences between plant and animal cells.
- Cell wall: Present in plant cells, absent in animal cells
- Chloroplasts: Present in plant cells, absent in animal cells
- Vacuoles: Large central vacuole in plant cells, small multiple vacuoles in animal cells
- Shape: Regular in plant cells, irregular in animal cells
- Size: Generally larger in plant cells, generally smaller in animal cells
- Storage: Starch granules in plant cells, glycogen granules in animal cells
What is the basic structural and functional unit of all living organisms?
Cell.
What is a tissue?
Group of similar cells that work together to perform a specific function.
Define an organ.
Structure composed of different tissues working together for specific functions.
What is an organ system?
Group of organs working together to perform a particular function.
What does an organism refer to?
Complete living entity capable of carrying out all life processes.
What are the four main types of tissue?
- Epithelial Tissue
- Connective Tissue
- Muscular Tissue
- Nervous Tissue
What is the function of the digestive system?
Breaks down food for absorption and eliminates waste.
What does the respiratory system do?
Exchanges gases between organism and environment.
What is the role of the circulatory system?
Transports materials throughout the body.
What is the function of the excretory system?
Removes metabolic wastes from the body.
What is the purpose of the nervous system?
Coordinates responses to internal and external stimuli.
What does the endocrine system regulate?
Body functions through hormones.
What is the reproductive system responsible for?
Produces offspring for continuation of species.
What does the skeletal system provide?
Support, protection, and enables movement.
What is the function of the muscular system?
Enables movement through contraction.
What does the integumentary system provide?
Protection from external environment.
Define an ecosystem.
A biological community of interacting organisms and their physical environment.
What are biotic components of an ecosystem?
Living organisms (producers, consumers, decomposers).
What are abiotic components of an ecosystem?
Non-living factors (temperature, water, soil, light, pH).
What is a food chain?
Linear sequence showing energy transfer from one organism to another.
What is a food web?
Interconnected food chains showing complex feeding relationships.
What are the trophic levels?
- Producers (Autotrophs)
- Primary Consumers (Herbivores)
- Secondary Consumers
- Tertiary Consumers
- Decomposers
How does energy flow in ecosystems?
Energy enters ecosystem through photosynthesis.
What is the 10% rule in energy transfer?
Only about 10% of energy transfers between trophic levels.
What are ecological pyramids?
- Pyramid of Numbers
- Pyramid of Biomass
- Pyramid of Energy
What is the carbon cycle?
- Carbon dioxide removed from atmosphere by photosynthesis
- Carbon returned through respiration, decomposition, combustion
- Carbon stored in fossil fuels, oceans, and biomass
What is nitrogen fixation?
Conversion of atmospheric N₂ to ammonia.
What is the process of nitrification?
Conversion of ammonia to nitrites and nitrates.
What is the water cycle?
- Evaporation
- Condensation
- Precipitation
- Runoff and infiltration
What is pollution?
Introduction of harmful substances into the environment.
What are the effects of climate change?
- Rising temperatures
- Extreme weather
- Sea level rise
What is autotrophic nutrition?
Organisms produce their own food.
What is photosynthesis?
Process by which green plants and some other organisms use sunlight to synthesize foods from carbon dioxide and water.
What is the equation for photosynthesis?
6CO₂ + 6H₂O + light energy → C₆H₁₂O₆ + 6O₂.
What are the light-dependent reactions?
Occur in thylakoid membranes; chlorophyll absorbs light energy.
What is the role of the small intestine in digestion?
Main sites of digestion and absorption; villi increase surface area for absorption.
What is the function of the liver?
Produces bile, detoxifies blood, stores glycogen, vitamins, minerals, and produces plasma proteins.
What is the function of amylase?
Breaks down starch into maltose.
What is mechanical digestion?
Physical breakdown of food.
What is chemical digestion?
Enzymatic breakdown of food molecules.
What is absorption in the context of digestion?
Passage of digested nutrients into the bloodstream.
What are macronutrients?
- Carbohydrates
- Proteins
- Lipids (Fats and Oils)
What are micronutrients?
- Vitamins
- Minerals
What is the function of water in the body?
Transport medium, temperature regulation, solvent.
What is protein-energy malnutrition?
Kwashiorkor and Marasmus.
What causes iron deficiency anemia?
Insufficient iron intake.
What is the definition of obesity?
Excessive fat accumulation (BMI ≥ 30).
What is aerobic respiration?
Breakdown of glucose in the presence of oxygen.
What is the energy yield from aerobic respiration?
36-38 ATP molecules per glucose molecule.
What is anaerobic respiration?
Breakdown of glucose in the absence of oxygen.
