Biology concepts, explained
- How does the immune system recognise a pathogen?
The immune system detects pathogens by matching its own receptor proteins to unique molecular patterns, called antigens, found on the pathogen's surface.
- What is homeostasis, with examples?
Homeostasis is the biological process that maintains a stable internal environment in your body, regulating things like temperature and blood sugar.
- How does the nervous system send signals?
The nervous system sends signals using electrical impulses called action potentials and chemical messengers called neurotransmitters.
- What is carrying capacity?
Carrying capacity is the maximum population size of a species that a specific environment can sustain indefinitely given its available resources.
- How do you read a phylogenetic tree?
Learn how to read a phylogenetic tree to understand evolutionary relationships, trace common ancestors, and see how species evolved over time.
- What is the difference between a food chain and a food web?
A food chain shows a single path of energy transfer, while a food web connects multiple food chains to show all feeding relationships in an ecosystem.
- What is ATP and why is it important?
ATP (adenosine triphosphate) is the primary energy carrier in living cells, providing the immediate power needed for essential cellular processes.
- What happens in each stage of cellular respiration?
Cellular respiration breaks down glucose in three stages (glycolysis, the Krebs cycle, and the electron transport chain) to produce ATP energy for the cell.
- What is natural selection, with an example?
Natural selection is the process where organisms with traits better suited to their environment survive and reproduce, changing the population over time.
- How does photosynthesis work step by step?
Photosynthesis converts sunlight, water, and carbon dioxide into glucose and oxygen through two main stages: light-dependent reactions and the Calvin cycle.
- What is the central dogma of molecular biology?
The central dogma of molecular biology explains how genetic information flows from DNA to RNA to create functional proteins in a cell.
- How does DNA replication work?
DNA replication is the process cells use to copy their genetic code before dividing, using enzymes to unzip and rebuild the double helix.
- What is the difference between genotype and phenotype?
Genotype is the specific genetic code stored in your DNA, while phenotype is the observable physical trait that results from those genes.
- How do you use a Punnett square?
Learn how to set up a Punnett square to predict genetic outcomes, understand dominant and recessive alleles, and calculate offspring probabilities.
- How does osmosis work?
Osmosis is the movement of water across a semipermeable membrane from an area of low solute concentration to high solute concentration to balance the system.
- What is the difference between mitosis and meiosis?
Understand the key differences between mitosis and meiosis, including their distinct purposes, chromosome counts, and roles in cellular reproduction.
- How does the cell membrane control what gets in and out?
The cell membrane controls transport using a selectively permeable phospholipid bilayer and specialized proteins to move specific molecules.
- What is the difference between prokaryotic and eukaryotic cells?
Prokaryotic cells are small and lack a nucleus, while eukaryotic cells are larger and contain a nucleus along with other membrane-bound organelles.