Both statements are correct.

Biodiversity is normally greater in the lower latitudes as compared to the higher latitudes because of several reasons such as favorable climatic conditions, longer periods of sunlight, and high primary productivity. The lower latitudes are also characterized by diverse and complex ecosystems, such as rainforests and coral reefs, which support a wide variety of plant and animal species.

Along the mountain gradients, biodiversity is normally greater in the lower altitudes as compared to the higher altitudes. This is because the lower altitudes have more favorable environmental conditions, such as higher temperatures and greater precipitation, which support more diverse ecosystems. As we move up the mountain, the environmental conditions become more extreme, such as lower temperatures, less precipitation, and harsher winds, which limit the diversity of life forms that can survive. The lower altitudes also offer more habitat diversity, such as forests, grasslands, and wetlands, which support different species of plants and animals.