Refer to the Following Information to Answer the Question

question 53

Multiple Choice

Refer to the following information to answer the question.
Fossils of Lystrosaurus, a dicynodont therapsid, are most common in parts of modern-day South America, South Africa, Madagascar, India, South Australia, and Antarctica. The animal apparently lived in arid regions and was mostly herbivorous. It originated during the mid-Permian period, survived the Permian extinction, and dwindled by the late Triassic, though there is evidence of a relict population in Australia during the Cretaceous period. Some dicynodonts had two large tusks, extending down from their upper jaws. The tusks were not used for food gathering, and in some species were limited to males. Food was gathered using an otherwise toothless beak. Judging from the fossil record in sedimentary rocks, these pig-sized organisms were the most common mammal-like reptiles of the Permian.
What is thought to be the correct sequence of these events, from earliest to most recent, in the evolution of life on Earth?
1) origin of mitochondria
2) origin of multicellular eukaryotes
3) origin of chloroplasts
4) origin of cyanobacteria
5) origin of fungal-plant symbioses

• A) 4, 3, 2, 1, 5
• B) 4, 1, 2, 3, 5
• C) 4, 1, 3, 2, 5
• D) 4, 3, 1, 5, 2

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Definitions:

Neurotransmitters

Chemical messengers in the brain that transmit signals from one neuron to another, influencing mental processes and behavior.

Knob-like Terminals

The expanded areas at the end of axons that are responsible for releasing neurotransmitters into the synapse.

Action Potential

A rapid change in electrical charge across a neuron's cell membrane, allowing for the transmission of nerve impulses.

Excitatory Signals

These are biochemical impulses that promote or increase neural activity or the firing of neurons.