Define the term 'allele'.
An allele is one of two or more versions of a gene that determine a particular trait.
Define ecological succession.
Ecological succession is the process of change in species structure of an ecological community over time.
Describe the fluid mosaic model of cell membranes.
The fluid mosaic model depicts the cell membrane as a fluid, dynamic structure with various proteins embedded in or attached to a bilayer of phospholipids.
Describe the process of osmosis.
Osmosis is the diffusion of water across a selectively permeable membrane from a region of lower solute concentration to higher concentration.
Define the concept of an ecological pyramid.
An ecological pyramid represents the distribution of biomass, numbers, or energy among trophic levels in an ecosystem.
Describe the process of nitrogen fixation.
Nitrogen fixation is the conversion of atmospheric nitrogen (N2) into a form usable by plants (ammonia, NH3).
Describe the function of the large intestine in the human digestive system.
The large intestine absorbs water and electrolytes, forming and storing feces.
Define population density.
Population density is the number of individuals of a species per unit area or volume.
Describe the function of the large central vacuole in plant cells.
The large central vacuole stores water and nutrients, maintains turgor pressure, and can contain waste products.
Describe the principle of segregation in genetics.
Mendel's principle stating that during gamete formation, the alleles for each gene segregate from each other so that each gamete carries only one allele for each gene.
Define the process of transcription.
Transcription is the synthesis of mRNA from a DNA template.
Describe the law of independent assortment.
Mendel's law stating that genes for different traits can segregate independently during gamete formation.
Describe the Bohr effect in hemoglobin.
The Bohr effect describes how hemoglobin's oxygen binding affinity decreases under conditions of low pH and high CO2, enhancing oxygen release.
Define Batesian mimicry.
Batesian mimicry is a form of mimicry where a harmless species resembles a harmful or poisonous one to deter predators.
Define genetic drift and its types.
Genetic drift is the change in allele frequency due to random events. Types: bottleneck effect, founder effect.
Define the term 'biome'.
A biome is a large ecological area with distinct climate, flora, and fauna, like tundra or rainforest.
Define Hardy-Weinberg equilibrium and its conditions.
Hardy-Weinberg equilibrium describes a non-evolving population. Conditions: no mutations, random mating, no natural selection, extremely large population size, no gene flow.
Describe the process of binary fission in bacteria.
Binary fission is a method of asexual reproduction where a bacterial cell divides into two genetically identical daughter cells.
Describe the process of chemotaxis in bacteria.
Chemotaxis is the movement of bacteria toward or away from chemical stimuli, like nutrients or toxins.
Describe the function of the xylem and phloem in plants.
Xylem transports water and minerals from roots to leaves; phloem distributes sugars and other metabolites from leaves to other parts of the plant.
Describe the process of facilitated diffusion.
Facilitated diffusion is the movement of molecules across a cell membrane through protein channels, from high to low concentration, without energy.
Define allopatric speciation.
Allopatric speciation is the formation of new species due to geographic isolation.
Define the term 'operon'.
An operon is a unit of DNA containing a cluster of genes under control of a single promoter, regulated together.
Define sympatric speciation.
Sympatric speciation is the evolution of new species from a common ancestor while inhabiting the same geographic region.
Define the greenhouse effect.
The greenhouse effect is the warming of Earth's surface due to the trapping of heat by greenhouse gases in the atmosphere.