🐾 • Lesson 1.1 : Organisms and Cells (Bio) Flashcards
After this lesson, you will be able to describe the characteristics of living organisms, and know how to explain the structures of a plant cell and an animal cell in Biology.
Describe Movement
Movement is an action by an organism or a part of an organism causing a change of position or place.
Describe Respiration
Respiration is the chemical reaction in cells that break down nutrient molecules and releases energy for metabolism.
Describe Sensitivity
Sensitivity is the ability to detect and respond to changes in the internal or external environment.
Describe Growth
Growth is a permanent increase in size and dry mass.
Describe Reproduction
Reproduction is the process that make more of the same kind of organism
Describe Excretion
Excretion is the removal of waste products of metabolism and substances in excess of requirements.
Describe Nutrition
Nutrition is taking in materials for energy, growth and development.
What structures do plant cells have that animal cells don’t?
Cell wall (for support),
Chloroplasts (for photosynthesis),
Large central vacuole (for storage).
What do both plant and animal cells have in common?
Cell membrane (controls movement),
Nucleus (contains DNA),
Cytoplasm (chemical reactions),
Mitochondria (energy production),
Ribosomes (make proteins).
What structures does a bacterial cell have?
Cell wall – for protection and support,
Cell membrane – controls movement in and out,
Cytoplasm – where chemical reactions happen.
How is bacterial DNA different from plant/animal cells?
Circular DNA – floats in cytoplasm, no nucleus,
Plasmids – small extra DNA rings with special genes.
How are new cells produced?
By the division of existing cells (Mitosis/Meiosis)
What do ciliated cells do?
Ciliated cells move mucus in the trachea and bronchi.
What do root hair cells do?
Root hair cells are there for absorption.
What do palisade mesophyll cells do?
Photosynthesis
What do neurones do?
Neurones conduct electrical impulses.
What do red blood cells do?
RBC transport oxygen
What do sperm and egg cells (gametes) do?
Reproduction.
What is the magnification formula?
Magnification = image size/actual size
What is the diffusion of cells?
Diffusion is the movement of particles from high to low concentration due to random motion.
How do substances move in and out of cells?
By diffusion through the cell membrane, from high to low concentration.
Why is diffusion important in living organisms?
For Gases – Oxygen in, Carbon dioxide out (ex. breathing).
For Solutes – Nutrients and waste move in and out of cells.
What factors affect diffusion?
Bigger (Surface area), Hotter (Temperature), Steeper (Concentration gradient), Shorter (Distance) = Faster Diffusion!
What is osmosis?
Osmosis is the movement of water through a partially permeable membrane from high to low water potential (from dilute to concentrated solution).
How does water move in and out of cells?
Water moves by osmosis through the cell membrane.
What happens when plant tissues are placed in different solutions?
In a dilute solution: Plant cells become turgid (swollen with water).
In a concentrated solution: Plant cells undergo plasmolysis (shrink and pull away from the wall).
What is turgor pressure and why is it important?
Turgor pressure is the pressure exerted by the cell membrane against the cell wall when water enters. It keeps plant cells turgid (firm).
How does osmosis help organisms with water uptake?
Osmosis allows organisms to take in water or lose water to maintain balance and proper function, especially in plant cells.
What is active transport?
Active transport moves particles from low to high concentration (against the gradient) using energy from respiration.
Why is active transport important?
It allows cells to move molecules or ions across membranes, like ion uptake in root hairs to support plant growth.
