Biology 1

• All life consists of cells.
• Cells can be seen with a normal light microscope, but electron microscopes allow us to see finer details.
• Magnification can be used to calculate the actual size of a cell.
• Eukaryotic cells have a nucleus, while prokaryotic cells do not.
• Both eukaryotic and prokaryotic cells contain similar organelles.
• The cell membrane is semi-permeable and keeps everything inside the cell.
• Plant cells and most bacteria have an extra cell wall made of cellulose.
• Cytoplasm is the liquid that makes up the cell and where most chemical reactions take place.
• Food tests can identify the presence of nutrients such as starch, sugars, proteins, and lipids
• Enzymes are biological catalysts that break down larger molecules into smaller ones
• The respiratory system is responsible for breathing and gas exchange
• Enzymes are specific and work on a lock and key principle
• The circulatory system is a double circulatory system where blood enters the heart twice
• The gallbladder neutralizes stomach acid and emulsifies fats to increase their surface area for faster breakdown
• Arteries carry oxygenated blood away from the heart, while veins carry deoxygenated blood towards the heart
• The rate of enzyme activity increases with temperature until the enzyme denatures
• Mitochondria is where respiration takes place and releases energy for the cell.
• Aerobic respiration occurs in cells and organisms with the presence of oxygen, and it is the process where glucose is broken down to provide energy for various cellular functions.
• A practical method to measure the rate of photosynthesis involves submerging Pond weeds in an inverted measuring cylinder and measuring the volume of oxygen produced over time.
• Metabolism refers to the sum of all reactions in a cell or organism, including respiration, synthesis of various molecules, and breakdown of excess substances.
• Anaerobic respiration occurs when there is a lack of oxygen, and glucose is converted into lactic acid or ethanol and carbon dioxide, depending on the organism.
• Light intensity can be an independent variable in the measurement of photosynthesis rate, which can be varied by changing the distance from the light source.
• Temperature can be a limiting factor in a process, such as the rate of photosynthesis.
• Ribosomes are where proteins are assembled or synthesized.
• Plant cells also contain chloroplasts for photosynthesis and a permanent vacuole for storing sap.
• Bacteria multiply by binary fission, doubling in number every certain time period.
• After six hours, the number of bacteria can be calculated using the formula 2 to the power of 36.
• Aseptic technique is used to prevent contamination when producing a culture on agar in a Petri dish.
• Osmosis is the diffusion of water across a semi-permeable membrane.
• Diffusion is the movement of molecules from an area of high concentration to an area of low concentration.
• Cells organize into tissues, which form organs, and organs work together in organ systems.
• New cells are made through the process of mitosis, where genetic material is duplicated and divided into two identical cells.
• Humans have 23 pairs of chromosomes in every nucleus, called diploid cells.
• Eukaryotic cell nuclei contain DNA stored in several chromosomes.
• The size of the culture can be calculated using the area of the circles formed.
• Active transport is the movement of substances through a membrane using energy.
• Examples of organ systems include the circulatory system and the digestive system.
• Stem cells can be used to combat conditions like diabetes and paralysis.
• Cloning plants can prevent species from becoming extinct or produce crops with specific characteristics.
• Incubating the culture at 25 degrees allows it to grow.