SUMMARY • The Hardy-Weinberg equilibrium describes the phenomenon whereby allele frequencies in a non-changing population do not change between generation • This describes an idealise state that population geneticists use to study past and present genotype frequencies...
XYLEM The xylem transports water and minerals from the roots up the plant stem and into the leaves. In a mature flowering plant or tree, most of the cells that make up the xylem are specialised cells called vessels. Vessels: • Lose their end walls so the xylem forms a...
Species = group of organisms which are able to breed freely to produce fertile offspring. Courtship behaviour = precursor behaviour to mating. Courtship behaviours are often species-specific and therefore aid in species recognition. • Process by which we allocate...
CELL ULTRASTRUCTURE • Chloroplasts • Amyloplasts • Vacuole • Tonoplast • Plasmodesmata • Pits • Cellulose cell wall • Middle lamella CHLOROPLASTS belong to a family of closely related plant organelles called plastids. They contain pigment chlorophyll. They are the...
FOXGLOVES • Foxgloves – Digitalis purpurea • The leaves are poisonous when eaten by humans and animals. • They have a string bitter taste as a warning. • Symptoms of poisoning: o Dizziness o Vomiting o Diarrhoea o Hallucinations o Heart failure – irregular heart beat...
• The variety of living species • The degree of nature’s variety • It allows for the permanent stability of an ecosystem • Involves an equilibrium between species. Biodiversity can be considered at different levels. HABITAT • Range of habitats • Each may be occupied...