Natural Vegetation and Habitats

Dark skin contains higher melanin content, which provides protection against harmful ultraviolet (UV) radiation from the sun. Tropical regions near the equator receive the most intense and direct UV radiation throughout the year. People inhabiting these regions have evolved darker skin as an adaptive trait to shield against UV damage. Temperate, desert, and forest regions don't have the same consistent, intense UV exposure levels that would select for this adaptation.

While deserts may have cacti or oases, the defining characteristic of all deserts is that they are 'arid' (extremely dry). 'Flat' is not a requirement for a desert, as many have dunes or mountains.

Steppes are the temperate grasslands of Europe and Asia, characterized by treeless plains and extreme seasonal temperatures. Prairies (A) are North American grasslands. Pampas (C) are South American grasslands. Savannas (D) are tropical grasslands with scattered trees, found in Africa and elsewhere.

Coral reefs require specific conditions to thrive: warm, clear, shallow tropical waters with temperatures between 23-29°C. They are predominantly found between 30°N and 30°S latitudes, which corresponds to tropical and subtropical regions. This is because reef-building corals have a symbiotic relationship with zooxanthellae algae that need sunlight for photosynthesis. False would be incorrect as this geographical distribution is a fundamental fact about coral reefs.

Giant pandas live in temperate bamboo forests in the mountains of central China. These forests are classified as temperate, not tropical or boreal. Temperate Forest (A) is correct.

Coconut palms (Cocos nucifera) are tropical plants that require warm, humid climates and cannot survive in cold or freezing temperatures. They grow best in tropical regions within 23 degrees of the equator where temperatures consistently remain above 60°F (15°C).

The Taiga biome, also known as the boreal forest, is a sub-Arctic biome characterized by coniferous forests. It spans across the northern regions of North America, Europe, and Asia, just south of the Arctic tundra. The Taiga is the world's largest terrestrial biome and is adapted to cold climates with long winters and short summers. Options B (sub-Saharan) and C (savanna grass) are incorrect as they refer to tropical regions.

Marine ecosystems cover approximately 71% of Earth's surface, making them the largest ecosystem by area. Oceans and seas dominate the planet's surface area, far exceeding the coverage of deserts, grasslands, or mountain ecosystems which are confined to land areas that make up only 29% of Earth's surface.

Endemic species are those found naturally only in a particular geographic location and nowhere else. Extinct species no longer exist, endangered species are at risk of extinction, and flora/fauna simply refer to plants and animals without geographic restriction.

Coconut palms are tropical plants that require warm climates to thrive. They cannot survive in cold temperatures or frost, making warm tropical regions their ideal habitat.

Savannahs are tropical grasslands found near the equator with distinct wet and dry seasons. Taiga is a boreal forest biome, while Pampas (South America) and Prairies (North America) are temperate grasslands.