paper 1 Flashcards
Q: What are the two types of cells?
A: Prokaryotic (no nucleus, e.g., bacteria) and eukaryotic (nucleus, e.g., animal and plant cells).
Q: What are the key organelles of a eukaryotic cell and their functions?
A:
Nucleus: Controls cell activities, contains DNA.
Cytoplasm: Site of chemical reactions.
Cell Membrane: Regulates substance movement.
Mitochondria: Site of aerobic respiration.
Ribosomes: Site of protein synthesis.
Chloroplasts (plants): Site of photosynthesis.
Cell Wall (plants and bacteria): Provides structure and support.
Vacuole (plants): Stores cell sap and maintains pressure
Q: Name four specialized cells and their adaptations.
A:
Sperm Cell: Tail for movement, mitochondria for energy, enzymes to penetrate egg.
Nerve Cell: Long axon for signal transmission, dendrites for connections.
Muscle Cell: Protein fibers for contraction, many mitochondria for energy.
Root Hair Cell: Large surface area for absorption, thin walls for easy diffusion.
Q: What is mitosis, and what is its purpose?
A: Mitosis is cell division that produces two identical daughter cells for growth and repair.
Q: What are the stages of the cell cycle?
A:
Interphase: DNA replication and cell growth.
Mitosis: Division of the nucleus.
Cytokinesis: Division of the cytoplasm.
Q: What are stem cells, and what are their uses?
A:
Definition: Undifferentiated cells that can develop into other types of cells.
Uses: Treating conditions like paralysis and diabetes.
Q: What is diffusion?
A: The movement of particles from an area of high concentration to an area of low concentration.
Q: What factors affect diffusion?
A: Concentration gradient, temperature, and surface area.
Q: What is osmosis?
A: The diffusion of water across a semi-permeable membrane from low solute concentration to high solute concentration.
Q: What is active transport?
A: The movement of substances against a concentration gradient, requiring energy (ATP).
Q: Name examples of active transport.
A: Mineral uptake in roots and glucose absorption in the intestines.
Q: What is the hierarchy of organization in biology?
A: Cells → Tissues → Organs → Organ Systems → Organism.
Q: What are the key enzymes in digestion and their functions?
A:
Amylase: Breaks down starch into sugars.
Protease: Breaks down proteins into amino acids.
Lipase: Breaks down lipids into glycerol and fatty acids.
Q: How does bile aid digestion?
A: Neutralizes stomach acid and emulsifies fats.
Q: What are the three types of blood vessels and their characteristics?
A:
Arteries: Thick walls, carry blood away from the heart.
Veins: Thin walls, valves prevent backflow, carry blood to the heart.
Capillaries: One-cell-thick walls for exchange.
Q: What are the components of blood?
A:
Red Blood Cells: Carry oxygen.
White Blood Cells: Fight infection.
Platelets: Help with clotting.
Plasma: Transports substances like CO₂ and nutrients.
Q: What is a pathogen?
A: A microorganism that causes disease.
Q: Name the four types of pathogens with examples.
A:
Bacteria: Salmonella, gonorrhea.
Viruses: HIV, measles.
Fungi: Rose black spot.
Protists: Malaria.
Q: How can pathogens be transmitted?
A: Through direct contact, water, air, or vectors like mosquitoes.
Q: How does the immune system respond to pathogens?
A: White blood cells produce antibodies, antitoxins, and engulf pathogens (phagocytosis).
Q: How do vaccines work?
A: Introduce dead/inactive pathogens to stimulate antibody production.
Q: What are antibiotics, and why don’t they work on viruses?
A: Antibiotics kill bacteria; they don’t affect viruses because viruses live inside host cells.
Q: What is the equation for photosynthesis?
A: 6CO2 + 6H2O — (LIGHT) –> C6H12O6 + 6O2
Q: What factors affect the rate of photosynthesis?
A: Light intensity, carbon dioxide concentration, and temperature.
