The Brazil Nut Tree, Bertholletia Excels (N = 17), Is

question 2

Multiple Choice

The Brazil nut tree, Bertholletia excels (n = 17) , is native to tropical rain forests of South America. It is a hardwood tree that can grow to over 50 metres tall, is a source of high-quality timber, and is a favourite nesting site for harpy eagles. As the rainy season ends, tough-walled fruits, each containing 8-25 seeds (Brazil nuts) , fall to the forest floor. Brazil nuts are composed primarily of endosperm. About $50 million worth of nuts are harvested each year. Scientists have discovered that the pale yellow flowers of Brazil nut trees cannot fertilise themselves and admit only female orchid bees as pollinators. The agouti (Dasyprocta spp.) , a cat-sized rodent, is the only animal with teeth strong enough to crack the hard wall of Brazil nut fruits. It typically eats some of the seeds, buries others, and leaves still others inside the fruit, which moisture can now enter. The uneaten seeds may subsequently germinate.
The same bees that pollinate the flowers of the Brazil nut trees also pollinate orchids, which are epiphytes (in other words, plants that grow on other plants) ; however, orchids cannot grow on Brazil nut trees. These observations explain ________.

• A) the coevolution of Brazil nut trees and orchids
• B) why Brazil nut trees do not set fruit in monoculture plantations
• C) why male orchid bees do not pollinate Brazil nut tree flowers
• D) why male orchid bees are smaller than female orchid bees

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Definitions:

Synapse

The junction between two neurons or between a neuron and a muscle where impulses pass by diffusion of a neurotransmitter.

Postsynaptic Membrane

The postsynaptic membrane is the region of a neuron that receives neurotransmitters from another neuron across the synaptic gap, playing a crucial role in neuron-to-neuron communication.

Synaptic Vesicle

A small, spherical sac that contains neurotransmitters, located within the terminal buttons of neurons, and is responsible for releasing neurotransmitters into the synaptic cleft.

Micrometer

A precision instrument used to measure small distances or thicknesses between two points, typically used in engineering and machining.