Question 1

Which of the following is NOT a level in MacLean's triune brain theory?

Accepted Answer

Machiavellian is not a level in MacLean's triune brain theory. The three levels are reptilian, paleomammalian, and neomammalian.

Question 2

Brain structures closer to midline dividing the left and right hemispheres are referred to as _____, whereas those farther away from the midline are called _____.

Accepted Answer

The structures that are closer to the midline, dividing the left and right hemispheres, are referred to as medial structures. The structures that are farther away from the midline are called lateral structures. The other answer choices are referring to different brain structures or directional terms that are not relevant to this question.

Question 3

Although mammals have been seen as evolving from reptiles, there are three types of behavior seen in mammals but not in reptiles. Which of the following is NOT one of these mammal-specific behaviors?

Accepted Answer

Courtship rituals are not unique to mammals and can be observed in many other animal groups, including reptiles, birds, and insects. Audio-vocal communication, maternal care, and play behavior are three behaviors that are uniquely evolved in mammals.

Question 4

The neural networks that are active during internal processing are called the brain's _____, which is most active when individuals are engaged in private thoughts or left alone to think about real or hypothetical events.

Accepted Answer

The neural networks that are active during internal processing are known as the default network, which is most active during periods of introspection or when individuals are engaged in private thoughts or imagining real or hypothetical scenarios. The default network is involved in self-referential thinking, social cognition, and memory retrieval.

Question 5

Because early mammals were nocturnal, they mostly relied on

Accepted Answer

Early mammals were nocturnal, meaning they were active during the night. As a result, they relied heavily on their senses of hearing and smell to navigate in the darkness and hunt for their prey. While they also had some degree of vision, it was likely not as developed as their other senses given the lack of available light during their active periods. Touch was likely important as well, but not to the same extent as hearing and smell.

Question 6

Which of the following is NOT one of the lobes of the brain?

Accepted Answer

While the brain is divided into different lobes, such as the frontal, parietal, and temporal lobes, caudal is not one of them. The term caudal refers to a position in the body relative to the head, but it is not a specific lobe of the brain.

Question 7

Although our human brain is only about 2% of our body weight, it uses some _____% of our energy.

Accepted Answer

The human brain uses approximately 20-25% of our body's energy, even though it only constitutes about 2% of our body weight.

Question 8

One approach to studying brain evolution and size examines the relationship between specific behaviors and the underlying cortical structures; this is known as the _____ approach.

Accepted Answer

The neuroethological approach examines the relationship between behavior and cortical structures, which is relevant to the study of brain evolution and size. The allometric approach examines the relationship between body size and brain size across species, the ontological approach focuses on the ontogeny (development) of brain structures, and the taxonomic approach examines differences in brain structures across different taxa (e.g. mammals vs. birds).

Question 9

It is thought that brains first appeared about _____ million years ago.

Accepted Answer

Brains first appeared about 500 million years ago, during the Cambrian explosion, a period when there was a rapid increase in the diversity of life forms on Earth.

Question 10

Both bats and birds inherited forelimbs from a common ancestor, but each developed wings separately; thus, the forelimbs are _____ similarities, whereas the wings are _____ similarities.

Accepted Answer

The forelimbs of bats and birds have a common evolutionary origin and therefore are homologous similarities. However, the wings of bats and birds evolved separately and have different functions, making them analogous similarities.

Question 11

Around 2.4 million years ago, humans experienced a mutation in gene MYH16, which led to smaller jaw muscles. This mutation allowed us to

Accepted Answer

The MYH16 gene mutation allowed for smaller jaw muscles, which in turn allowed for a larger braincase and more space for brain expansion. This is known as the "expensive-tissue hypothesis" and suggests that the energy saved from smaller jaw muscles was redirected to fuel a larger brain, which allowed for the development of more complex language skills and other cognitive abilities.

Question 12

Even simple organisms such as single-cell protozoa share sophisticated behavior processes with higher-level organisms. Which of the following is NOT one such behavior?

Accepted Answer

The answer of Even simple organisms such as single-cell protozoa...

Question 13

Mammals have evolved a brain structure different from that of other organisms, namely the six-layered

Accepted Answer

The six-layered neocortex is a unique brain structure found in mammals, including humans. It is responsible for higher cognitive functions such as language, reasoning, and perception. The other options, allocortex, archicortex, and paleocortex, are all older forms of cortical structures found in other organisms, but not in the neocortex.

Question 14

Many neuroscientists view evolution in terms of increasing the size of the

Accepted Answer

Many neuroscientists view evolution in terms of increasing the size of the brain. This is because a larger brain typically means more neurons and greater cognitive abilities.

Answer: C 
 Another way that evolution can be viewed in terms of the brain is through the increasing number of convolutions, or folds, in the cerebral cortex. The greater number of convolutions allows for more surface area within the same skull size, which in turn allows for a greater number of neurons and more complex cognitive abilities.

Question 15

In studies of social intelligence in primates, group size alone has not been shown to be strongly correlated with brain size; however, Dunbar did find a positive correlation between _____ and relative brain size.

Accepted Answer

Dunbar's research showed that grooming behavior was positively correlated with relative brain size in primates. This suggests that the complexity of social relationships and the ability to maintain them may have played a role in the evolution of larger brains in these species. There is not strong evidence to link brain size specifically to hunting, mating, or playing behavior in primates.

Question 16

About 14 days following conception, a process referred to as _____ occurs, which leads to the development of three different cell lines from undifferentiated embryonic tissue.

Accepted Answer

Gastrulation is the process that occurs about 14 days following conception in which three different cell lines (endoderm, mesoderm, and ectoderm) develop from undifferentiated embryonic tissue. Encephalization refers to the process of brain development, myelination refers to the formation of myelin sheaths around nerve fibers, and hierarchical integration is a concept related to brain function and cognitive development.

Question 17

An important development that came with the larger brains in primates was the ability to connect information processing with _____, an ability that eventually led to a sense of self in humans.

Accepted Answer

The ability to connect information processing with time is an important development that came with the larger brains in primates. This temporal processing ability is crucial for planning, memory, and the development of a sense of self, distinguishing past, present, and future experiences.

Question 18

The nervous system of nocturnal mammals encouraged the evolution of _____, which later evolved into humans' ability to create internal representations of external events.

Accepted Answer

Nocturnal mammals needed to navigate in the dark, which led to the development of spatial maps in their brains. This ability eventually evolved in humans and allowed us to create internal representations of external events. Consciousness and gray matter are not directly related to the evolution of spatial maps, and while mental images may be a part of this ability, they are not the primary focus.

Question 19

If a particular characteristic was present in the ancestors of the group under study, it is called a _____ characteristic; if, on the other hand, the characteristic has evolved in the group under study, it is called a _____ characteristic.

Accepted Answer

The characteristic that was present in the ancestors of the group under study is called a primitive characteristic, while the characteristic that has evolved in the group under study is called a derived characteristic. Option A is incorrect because the terms "hierarchical" and "integrated" do not apply to the given context. Option B is incorrect because homologous and analogous characteristics are terms used to describe similarities and differences between characteristics, not their origins. Option C is also incorrect because inherited and acquired characteristics refer to how traits are passed down through generations, not their origins.

Question 20

Humans today share a number of characteristics with sea mammals. Which of the following is NOT one such characteristic?

Accepted Answer

Sea mammals, such as whales and dolphins, do not have body hair. Therefore, considerable body hair is not a characteristic shared between humans and sea mammals.

Quiz 4: Evolution of Brain and Function