Question 1

Although there are currently no effective treatments for Alzheimer's disease,symptoms may be slightly improved by using medications that

Accepted Answer

Boosting the activity of acetylcholine has been shown to improve cognitive symptoms in Alzheimer's disease, while inhibiting its activity may worsen symptoms. Dopamine is not typically targeted in treatments for Alzheimer's disease.

Question 2

Without contact with any other embryonic cells,an ectodermal cell will differentiate into skin.

Accepted Answer

The answer of Without contact with any other embryonic cells,an...

Question 3

Most of the drugs currently approved for treating Alzheimer's disease

Accepted Answer

The drugs approved for treating Alzheimer's disease inhibit acetylcholinesterase (AChE), which is the enzyme that breaks down acetylcholine (ACh), leading to an increase in its concentration. This is because a deficiency in ACh is one of the main causes of cognitive decline in Alzheimer's disease. Inhibiting the breakdown of ACh can therefore help to improve cognitive function in these patients.

Question 4

Plaques on axon terminals and within blood vessels serving the brain may result from

Accepted Answer

Plaques on axon terminals and within blood vessels serving the brain are a hallmark feature of Alzheimer's disease. These plaques are composed of beta-amyloid protein deposits and can lead to neurodegeneration and cognitive decline. Phenylketonuria (PKU), fetal alcohol syndrome, and fragile-X syndrome do not typically result in the formation of plaques in the brain.

Question 5

In cases of Alzheimer's disease,progressive degeneration of the brain may occur due to

Accepted Answer

Transneuronal degeneration refers to the process where neurons degenerate as a result of the loss of input from other neurons, which can occur in Alzheimer's disease as the disease progresses and affects neural networks.

Question 6

At the onset of Alzheimer's disease,the first areas of the brain to show degeneration are usually the

Accepted Answer

The hippocampus and the posterior cingulate cortex are typically the first areas of the brain to show degeneration in Alzheimer's disease. The hippocampus is important for memory formation and retrieval, while the posterior cingulate cortex is involved in various cognitive processes, including attention and perception. As the disease progresses, other areas of the brain, including the frontal and temporal lobes, may also be affected.

Question 7

Joan has one APOE³ and one APOE⁴ allele.This means Joan is heterozygous for the APOE gene.

Accepted Answer

Joan has different alleles for the APOE gene, which makes her heterozygous.

Question 8

Your grandmother is 80 years old and very active.She still reads,getting new books from the library every week,and walks every day.What is the most likely prognosis for your grandmother's cognitive abilities?

Accepted Answer

There is no evidence that cognitive decline is inevitable after age 80. In fact, many older adults maintain their cognitive abilities well into their later years, especially if they remain active and engaged in stimulating activities such as reading and exercise, as your grandmother does. Therefore, it is very possible that your grandmother will continue to be mentally alert and active right up until her death.

Question 9

An abnormal protein found in the brains of people with Alzheimer's disease is known as

Accepted Answer

The abnormal protein found in the brains of people with Alzheimer's disease is called amyloid. This protein clumps together and forms plaques which can damage nerve cells in the brain, leading to the symptoms of Alzheimer's disease. Sonic hedgehog and nerve growth factor are both proteins involved in the development and maintenance of the nervous system, but they are not directly associated with Alzheimer's disease. Phenylalanine is an amino acid and is not directly related to Alzheimer's disease either.

Question 10

Because the heritability of height is 81 percent,and the heritability of adult Body Mass Index (BMI)is 59 percent,we can conclude that genetics play a stronger role in the development of height than BMI.

Accepted Answer

The heritability of height (81%) is higher than that of adult BMI (59%), indicating that genetics play a stronger role in the development of height than BMI.

Question 11

Memantine improves the cognition of some patients with Alzheimer's disease by

Accepted Answer

Memantine improves cognition in some patients with Alzheimer's disease by blocking glutamate at the NMDA receptor. This reduces the toxic effects of excessive glutamate and protects against further damage to brain cells.

Question 12

At least in mice,aging can be slowed dramatically by

Accepted Answer

Studies have shown that in mice, caloric restriction can slow down aging, leading to longer lifespans and healthier aging. This is believed to be due to the fact that caloric restriction reduces oxidative stress and inflammation, which are both linked to aging and age-related diseases. On the other hand, increased calories can accelerate aging and increase the risk of age-related diseases. Exercise and sleep also play important roles in promoting healthy aging, but they may not have as dramatic an effect on lifespan as caloric restriction in mice. Sleep deprivation, in fact, can have detrimental effects on health and aging.

Question 13

About two-thirds of the cells traveling to the developing cortex follow radial glia,and the remaining one-third move in a horizontal direction instead,without using radial glia to guide them.

Accepted Answer

This statement is true. Two-thirds of the cells use radial glia as a guide to travel to the developing cortex, while the remaining one-third move in a horizontal (or tangential) direction.

Question 14

Critical periods occur in many animals,such as the imprinting observed in geese,but has not yet been observed in humans.

Accepted Answer

Critical periods have been observed in humans, such as the visual development critical period which occurs during the first few years of life. However, specific examples of imprinting like that observed in geese have not been observed in humans.

Question 15

Abnormal amyloid proteins are also found in the brains of people with:

Accepted Answer

Abnormal amyloid proteins are found in the brains of people with Down syndrome. This is because Down syndrome is associated with the overproduction of amyloid precursor protein (APP), which can lead to the formation of beta-amyloid plaques in the brain. Fragile-X syndrome, phenylketonuria, and fetal alcohol syndrome do not involve abnormal amyloid protein accumulation in the brain.

Question 16

Females are much more likely than males to develop conditions influenced by genes that are located on the X chromosome,because they have two X chromosomes instead of one.

Accepted Answer

Females have two X chromosomes, which means they have a backup copy of each gene on the X chromosome. This often provides protection against X-linked conditions, which are more commonly expressed in males who have only one X chromosome.

Question 17

Myelination of the human spinal cord and brain begins about 24 weeks following conception and is complete by the age of about 18 months.

Accepted Answer

Myelination in humans begins in the fetal stage but continues into adulthood, with significant myelination occurring into the second decade of life, not completing by 18 months.

Question 18

Medications that were commonly used to treat _________ have also been used to treat aggressive patients and improve cognition in patients with Alzheimer's disease.

Accepted Answer

Medications commonly used to treat schizophrenia, such as antipsychotics, have also been used to manage aggressive behavior in patients and improve cognition in patients with Alzheimer's disease. Medications used to treat depression, bipolar disorder, and ADHD are not commonly used for these purposes.

Question 19

Future interventions designed to slow the aging process may target

Accepted Answer

Telomeres are protective caps on the ends of chromosomes that shorten with each cell division and are associated with aging. Interventions that can slow down telomere shortening or even lengthen them may be a promising target to slow down the aging process. The other options - rates of myelination, prenatal apoptosis, and synaptic pruning - are all normal developmental processes that occur during the lifespan and are not necessarily directly linked to aging.

Question 20

In their research on nuns,Snowdon et al.discovered correlations between a person's likelihood for being diagnosed with Alzheimer's disease and her

Accepted Answer

Snowdon et al. found that nuns who wrote more complex sentences in essays they wrote in their teenage years were less likely to develop Alzheimer's disease later in life. This suggests that writing ability in early life may be a predictor of Alzheimer's risk.

Quiz 5: Genetics and the Development of the Human Brain