Biology
- alshevkun
- Jan 31
- 4 min read
Updated: Feb 3
The focus of this website is to simplify your learning process while keeping in mind our audience, the learners, so as a student i am here to provide you with my favourite trust worthy sources that i personally use when i study various biology topics!
Cells & organelles
Cells are the basic building blocks of all living things. Every living organism is made up of cells, and they come in two main types:
Prokaryotic cells: These are simple cells without a nucleus (like bacteria).
Eukaryotic cells: These are more complex and have a nucleus, where the cell’s genetic material is stored (like animal and plant cells).
Inside a cell, there are organelles – small structures that perform specific jobs to keep the cell alive. Here are some important organelles:
Nucleus: Acts like the cell's control center, containing DNA (the cell’s instructions).
Mitochondria: Known as the "powerhouse" of the cell, they produce energy.
Ribosomes: Make proteins, which are important for cell functions.
Endoplasmic Reticulum (ER): Helps transport materials within the cell (rough ER has ribosomes, smooth ER doesn't).
Golgi Apparatus: Sorts and packages proteins to be sent out of the cell.
Chloroplasts (in plant cells): Help make food through photosynthesis, using sunlight.
Genetics and dna
Genetics is the study of how traits are passed from parents to their offspring. It focuses on genes, which are small pieces of DNA that carry the instructions for how living things grow and develop.
DNA (Deoxyribonucleic Acid) is the molecule that contains all the genetic information. It looks like a long, twisted ladder, called a double helix. The "rungs" of the ladder are made of pairs of molecules called bases, and these bases are arranged in a specific order to form genes.
Each person has two copies of each gene, one from their mother and one from their father. These genes determine traits like eye color, height, and even some aspects of health. DNA is like a blueprint for building and operating all living things!
Body systems (circulatory, digestive..)
Circulatory System:
Purpose: Transports blood, nutrients, gases, and wastes throughout the body.
Key Components:
Heart: Pumps blood.
Blood vessels: Arteries, veins, and capillaries.
Blood: Carries oxygen, nutrients, and waste.
Digestive System:
Purpose: Breaks down food into nutrients that the body can absorb.
Key Components:
Mouth: Starts the process of digestion.
Esophagus: Moves food to the stomach.
Stomach: Breaks down food with acids.
Intestines: Absorb nutrients and water (small and large intestines).
Liver & Pancreas: Help process nutrients and produce digestive enzymes.
Respiratory System:
Purpose: Provides oxygen to the blood and removes carbon dioxide.
Key Components:
Lungs: Where gas exchange happens.
Trachea: Windpipe, carries air to lungs.
Bronchi: Airways that lead to the lungs.
Nervous System:
Purpose: Controls body activities and processes sensory information.
Key Components:
Brain: The control center of the body.
Spinal cord: Relays signals between the brain and body.
Nerves: Transmit signals throughout the body.
Muscular System:
Purpose: Allows movement and maintains posture.
Key Components:
Skeletal muscles: Attach to bones and allow voluntary movement.
Smooth muscles: Found in organs, control involuntary movements.
Cardiac muscles: Found in the heart, control heartbeats.
Skeletal System:
Purpose: Provides structure, protection, and support.
Key Components:
Bones: Provide structure and protect organs.
Joints: Allow movement between bones.
Cartilage: Cushions joints and supports tissues.
Excretory System:
Purpose: Removes waste from the body.
Key Components:
Kidneys: Filter waste from the blood.
Bladder: Stores urine.
Ureters & Urethra: Transport urine out of the body.
digestive: https://www.youtube.com/watch?v=vMI46qGQMDw&list=PLMGTjvwQ4TtC3Joiq-pXfxl1VZ8T3GgKt&index=3
circulatory:https://www.youtube.com/watch?v=zU90AkcTJEs&list=PLMGTjvwQ4TtC3Joiq-pXfxl1VZ8T3GgKt&index=5
respiratory:https://www.youtube.com/watch?v=B44n2SMLv-s&list=PLMGTjvwQ4TtC3Joiq-pXfxl1VZ8T3GgKt&index=7
nervous: https://www.youtube.com/watch?v=HiuXfbwND9s&list=PLMGTjvwQ4TtC3Joiq-pXfxl1VZ8T3GgKt&index=2
Respiration
Respiration is the process by which our bodies turn food into energy. It happens in every cell and is essential for life.
There are two types:
Aerobic respiration (with oxygen): This is the most common type, where cells use oxygen to break down glucose (sugar) from food, producing energy, carbon dioxide, and water. The energy is stored in a molecule called ATP(adenosine triphosphate), which powers the body's activities.
Formula: Glucose+Oxygen→Energy+Carbon dioxide+WaterGlucose+Oxygen→Energy+Carbon dioxide+Water
Anaerobic respiration (without oxygen): This occurs when oxygen is not available. It’s less efficient and produces less energy. For example, during intense exercise, muscles may temporarily rely on anaerobic respiration, which produces lactic acid as a byproduct.
Formula (for humans): Glucose→Energy+Lactic acidGlucose→Energy+Lactic acid
Diffusion and osmosis
Diffusion: This is the movement of particles (like molecules or ions) from an area of high concentration to an area of low concentration, until they are evenly spread out. It doesn’t require energy (it’s a passive process). For example, when you open a perfume bottle, the scent spreads throughout the room due to diffusion.
Example: Oxygen moving from the lungs into the bloodstream, where there’s a lower concentration of oxygen.
Osmosis: This is a specific type of diffusion, but it only involves the movement of water molecules. Water moves through a semipermeable membrane (a barrier that lets water pass but not all substances) from an area of low concentration of solutes (like salt or sugar) to an area of high concentration of solutes.
Example: Water moving into a plant cell where there’s a higher concentration of solutes inside, making the cell swell.
Sexual and asexual reproduction
Sexual Reproduction: This involves two parent organisms, usually a male and a female, who each contribute genetic material (sex cells, like sperm and eggs). The offspring has a combination of genes from both parents, making them genetically different. This leads to genetic diversity, which helps species adapt to changes over time. Examples include humans, animals, and most plants.
Asexual Reproduction: This involves just one parent, and the offspring is an exact genetic copy of the parent, meaning it’s genetically identical. It doesn’t require sex cells. Asexual reproduction is quicker and simpler. Examples include bacteria, some plants, and some animals like starfish.
Photosynthesis
Photosynthesis is the process by which plants make their own food using sunlight. They do this by turning carbon dioxide from the air and water from the soil into glucose (a type of sugar) and oxygen. This happens in the plant’s chloroplasts, which contain a green pigment called chlorophyll that absorbs sunlight.
The basic formula for photosynthesis is:
Carbon dioxide+Water+Sunlight→Glucose+OxygenCarbon dioxide+Water+Sunlight→Glucose+Oxygen
so helpful! 🤠