Physical geography Chapter 4: Rocks
Mineral A mineral is a naturally occurring substance which has certain physical properties and a definite chemical composition Rock A rock is an aggregate of ... Read More
Explain why the impermeability of an axon membrane to sodium ion in part of a neuron helps to maintain resting potential in that part of the neuron
Impermeability of the membrane prevents entry of sodium ions which would cause depolarization Read More
Explain why sickle cell trait is prevalent in malaria prone areas
Sickle cell trait is caused by a recessive allele in heterozygote state. Malaria acts as a selection pressure for heterozygote promoting their high occurrence in ... Read More
When light and temperature are optimum while carbon dioxide concentration is low, the rate of photosynthesis can’t increase further.
In isolated populations mutations and natural selection occurs differentially leading to evolution of new species Read More
Structure of the earth, continental drift and earthquakes
Physical geography Chapter 1: Structure of the earth, continental drift and earthquakes In the universe we live on planet earth, is the third planet from the ... Read More
Lateral and vertical Earth movement
Lateral earth movements They are diastrophic/large scale differential movements that operate horizontally within the earth crust. They are caused by internal forces i.e. tensional forces ... Read More
Physical geography Chapter 3: Vulcanicity in East Africa
Volcanism, volcanism or Vulcanicity is the phenomenon of eruption of molten rock (magma) onto the surface of the Earth or a solid-surface planet or moon, ... Read More
Shield volcanoes
Shield volcanoes are usually constructed almost entirely of basaltic and/or andesitic lava flows which were very fluid when erupted and flowed through several fissures . ... Read More
Ash and cinder cone meaning geography
cinder cone, also called ash cone, deposit around a volcanic vent, formed by pyroclastic rock fragments (formed by volcanic or igneous action), or cinders, which ... Read More
Oceanic Crust (SIMA)
Oceanic crust is made up of heavy basalt rocks (average density 3) and thickness between 5-10 kilometers (3-6 kilometers). SIMA stands for silicate and magnesium, ... Read More
Continental crust (SIAL)
Continental Crust Continental crust is made up of very old light rocks (average density 2.6) of mainly granites. SIAL stands for silicate and aluminum, the ... Read More
Types of plate tectonic boundaries
There are three types of Plate tectonic boundaries A divergent boundary(constructive plate boundary/margin) occurs when two tectonic plates move away from each other widening the gap ... Read More
Tectonic plates
Tectonic plates are blocks of continental and ocean crust. The earth’s surface is divided into blocks of continental and oceanic crust Characteristics of plates Plates ... Read More
Physical geography Chapter 2: Faulting and East Africa
Faulting is s the fracturing/ breaking/ rapturing/cracking of rocks due to strain and stress which subsequently leads to the dislocation and displacement of rock strata. ... Read More
Physical geography Chapter 1: Structure of the earth, continental drift andEarthquakes
In the universe we live on planet earth, is the third planet from the Sun at a distance of about 93 million miles (150 million km). is ... Read More
River capture – meaning
River capture may only occur where there are 2 adjacent rivers/ share a watershed One river has more erosive power than the other The more ... Read More
Account for the occurrence of large-scale mass wasting in the highland areas of East Africa
Candidates are expected to have the following approach Definition of mass wasting Identification of areas affected Description of types of types of mass wasting; (illustrations ... Read More
Solifluction
Solifluction is a collective name for gradual processes in which a mass moves down a slope ("mass wasting") related to freeze-thaw activity. Read More
Examine the relevance of the plate tectonic theory in the understanding of the present day distribution of oceans and land masses
Candidates should bring out the distribution of land masses and water bodies (oceans) in relation to tectonic plates It explains the movement and distribution of ... Read More
Distinguish between lateral and vertical earth movements
Lateral earth movements are diastrophic/large scale differential movements that operate horizontally within the earth crust They are caused by internal forces e. tensional forces (divergent ... Read More
Tectonism meaning
Tectonism is the faulting or folding or other deformation of the outer layer of a planet. Read More
Luvisolic soil/luvisols
Luvisolic soils are forest soils that form in medium- and fine-textured parent materials Read More
To what extent has altitude influenced vegetation distribution in East Africa?
The candidate is expected to: · Define vegetation. Identify the vegetation types in East Africa and their location. Examine the role of Altitude. Examine the ... Read More
Orographic rainfall
Orographic rainfall is precipitation produced when the mountains or uplands such as Mt. Kilimanjaro, Mt. Keny act as barriers to airflow, forcing the air to rise. ... Read More
Reaction of phosphorus with concentrated acid
Phosphorus gets oxidised to phosphoric acid according to the following reaction 2P+5H2SO4→2H3PO4+2H2O+5SO2. Read More
Explain the influence of ocean currents on the climate of Africa.
Africa's coastline is affected by the following ocean currents. The warm Mozambique/Agulhas ocean current on the Eastern coast of Southern Africa, the Benguela cool current ... Read More
What is ocean current?
Candidates are expected to:- Define ocean currents, explain the causes of ocean currents, identify the types of ocean currents i.e. warm and cold currents and ... Read More
Account for the occurrence of sea level
Candidates should define the term "sea-level changes'' as a rise or fall in the level of the sea relative to the land or the vertical ... Read More
Subduction-geography
Subduction occurs when an oceanic plate runs into a continental plate and slides beneath it. Read More
Eustatic change – meaning in geography
Eustatic sea level changes are changes in sea level due to changes in the volume of water in the ocean. These can be due to ... Read More
Explain the influence of earth movements on the formation of lakes in East Africa.
Candidates should define a lake as a hollow in the Earth's surface filled by water • Lakes in East Africa differ in permanency, salinity, shape, ... Read More
Gleying meaning
Gleying is a technical term that describes the gray, blue, purple or green soil colors that occur in soils that have been waterlogged 1 for prolonged periods of ... Read More
Describe the weathering processes taking place in the Lake Victoria basin of East
Candidates are expected to Define weathering Give the climatic conditions/characteristics of Lake Victoria basin Identify the types of weathering processes taking place in the Lake ... Read More
Examine the relevance of Wegner’s theory of continental drift in explaining the present day position of
Candidates are expected to define continental drift Continental drift is the movement of continental landmasses/blocks relative to one another (away, towards or alongside), across the ... Read More
Evaporites-meaning
Evaporites are layered crystalline sedimentary rocks that form from brines generated in areas where the amount of water lost by evaporation exceeds the total amount ... Read More
What is a coral reef?
Coral reef are are mad of millions of tiny animals that contain plant contain plants called algae. Coral reefs form at depths not exceeding 25 ... Read More
Palaeomagnetism
Palaeomagnetism is the study of magnetic fields recorded in rocks, sediment, or archeological materials. Read More
Distinguish between Azonal and Intrazonal soil
Azonal soils are young soils without a clear soil profile. They are soils that have not been exposed to soil forming processes for a long ... Read More
Solonchaks soil -geography
Solonchaks soil are soils that have a high concentration of 'soluble salts' at some time in the year. Solonchaks are largely confined to the arid ... Read More
Solonetzic soil-geography
Solonetzic soils, often called burnout or gumbo soils, are characterized by a tough, impermeable hardpan that may vary from 5 to 30 cm (2 to 12 ... Read More
Azonal soils
Azonal soils are young soils without a clear soil profile. They are soils that have not been exposed to soil forming processes for a long ... Read More
Explain the conditions that have influenced the distribution of mangrove forests in East Africa
Candidates are expected to identify areas in East Africa, with Mangrove forests/vegetation i.e. Areas along the coast of East Africa between 50Nand 50S of equator, ... Read More
Characteristics of Mangrove forests
The trees are evergreen because of high rainfall received throughout the year. Trees have broad leaves to get rid of excess water. Trees have aeria1/silt ... Read More
Examine the causes and effects of land and sea breezes in East
Candidates are expected to: Define land and sea Identify the areas where they occur in East Africa. Factors of land and sea breezes. Causes and ... Read More
Account for the variations in the temperature experienced in different areas of East Africa.
Candidates are expected to define temperature, should give brief description of variations in the temperature experienced in different areas of East Africa with specific examples ... Read More
Differentiate between annual range of temperature and diurnal range of temperature
Candidates are expected to differentiate between annual range of temperature and diurnal range of temperature. Annual range of temperature is the difference between the highest ... Read More
To what extent has relief influenced the development of drainage patterns in East Africa?
Candidates should define the term drainage pattern Drainage pattern is s the layout/plan or arrangement made by a river and its tributaries on the landscape ... Read More
Drainage pattern-geography
Drainage pattern is the layout/plan or arrangement made by a river and its tributaries on the landscape (Drainage basin) over which it flows. Read More
Describe the landforms resulting from chemical weathering in East
Candidates should define chemical weathering as the decomposition/decay/rotting of rocks at or near the earth surface. It occurs in situ (one place). Candidates should identify ... Read More
Polje – geography
Polje. This is an elongated basin having a flat floor and steep walls. The poljes are formed by coalescence of several sinkholes when being formed ... Read More
Limestone gorge
Limestone gorge is deep steep-sided valley formed when acid rain seeps into the cracks in limestone rocks or when a larger river erodes/ weathers soft ... Read More