Question 1

A researcher analyzing the likelihood that a cell will be responsive to a lipid-soluble hormone should search for the presence of

Accepted Answer

Lipid-soluble hormones can diffuse through the plasma membrane and bind to intracellular receptors in the cytoplasm or nucleus. Therefore, the presence of a specific receptor in the cytoplasm or nucleus is necessary to trigger a response from the target cell.

Question 2

The posterior pituitary gland

Accepted Answer

The posterior pituitary gland secretes hormones that are produced by neurons whose cell bodies are located in the brain. These hormones are transported down axons and stored in the posterior pituitary gland until they are released.

Question 3

A castaway on a deserted island puts a message in a bottle and throws it into the ocean, hoping it will wash up on some inhabited shore and bring help.In endocrine signaling, the ocean is analogous to

Accepted Answer

In endocrine signaling, hormones are released into the bloodstream to be transported to target cells or organs, similar to how the message in a bottle is released into the ocean to be carried to a distant shore.

Question 4

Hormones

Accepted Answer

Hormones can be secreted by individual cells, such as those lining portions of the digestive tract. These cells are known as enteroendocrine cells and they secrete hormones such as gastrin and secretin.

Answer: D
 Most hormones cannot pass through cell membranes after they have been secreted because they are typically large, complex molecules. Instead, they must bind to receptors on the surface of target cells to initiate a response.

Question 5

The hormone prolactin is found in different species, where it can have different functions.It is required for osmoregulation in freshwater fish, stimulates nesting in certain birds, and stimulates milk production in female mammals.In developing a hypothesis for how this occurred, the most reasonable assumption to make would be that

Accepted Answer

The fact that prolactin is found in different species and has different functions suggests that the structure of the hormone itself is highly conserved across species, while different responses have evolved. This is a common phenomenon in evolution, where a single trait or molecule can have multiple functions in different contexts. Additionally, it is unlikely that the gene for prolactin arose independently multiple times, as this would require numerous chance mutations in the same sequence across different species. Similarly, it is unlikely that different genes evolved to produce the same hormone without some level of common ancestry or conservation. Lastly, the receptors for prolactin are likely conserved across species, as they play a critical role in mediating the hormone's effects.

Question 6

Steroid hormones

Accepted Answer

Steroid hormones are lipids and, therefore, are not soluble in water. As a result, they need to bind with carrier proteins to be transported in the blood to their target cells. Once they reach their target cells, they can diffuse through the cell membrane and bind with intracellular receptors.

Question 7

If you want to make a name for yourself in science by identifying a type of hormone that has not yet been discovered, you should focus your research on

Accepted Answer

Carbohydrates are not typically associated with hormone function, making them a less explored area for hormone discovery compared to the other options.

Question 8

In the fight-or-flight response, the release of epinephrine inhibits insulin secretion but also triggers glucagon secretion in the pancreas.You are investigating how this hormone could have two different effects on the pancreas.Which possibility is most likely?

Accepted Answer

Epinephrine binding to two different receptors is the most likely explanation for its dual effects on the pancreas. Epinephrine binds to beta receptors on pancreatic cells, leading to the inhibition of insulin secretion, while it binds to alpha receptors, triggering glucagon secretion. This enables the body to release glucose into the bloodstream during the fight-or-flight response, providing additional energy for the body to respond to potential threats.

Question 9

Hormones released by the posterior pituitary are produced in the

Accepted Answer

Hormones released by the posterior pituitary are actually produced in the hypothalamus, which is located above and connected to the pituitary gland by a stalk called the infundibulum. The hypothalamus sends signals to the posterior pituitary to release hormones such as oxytocin and antidiuretic hormone (ADH).

Question 10

Which substance is a hormone that acts primarily on cells close to the source of the hormone?

Accepted Answer

Histamine is a local hormone that acts primarily on cells close to its source. It is involved in regulating local immune responses and inflammation. Adrenaline, estrogen, insulin, and thyroxine are all hormones that act on target cells throughout the body.

Question 11

You are investigating the evolutionary history of the hormone irisin that was recently discovered in mice.Released by skeletal muscle cells during exercise, it triggers the "browning" of white fat.Based on scientific thinking about the evolutionary history of hormones, it would be reasonable to hypothesize that

Accepted Answer

Based on scientific thinking about the evolutionary history of hormones, it is reasonable to hypothesize that irisin might be produced in many different groups of organisms, even in organisms such as sponges that lack skeletal muscle cells. Hormones have evolved multiple times in different groups of organisms over the course of evolution, and have been found in both prokaryotes and eukaryotes. Therefore, it is possible that irisin is not specific to mice and may be produced in different organisms.

Question 12

Portal blood vessels connect the _______ to the _______.

Accepted Answer

The portal blood vessels connect the hypothalamus (located in the brain) to the anterior pituitary gland. This connection allows for hypothalamic hormones to regulate the release of hormones from the anterior pituitary. The posterior pituitary is not connected via portal vessels, but instead releases hormones directly into the bloodstream. The pancreas and liver are not connected by portal blood vessels.

Question 13

All of these hormones are secreted by the anterior pituitary and are hormones that control the activities of other endocrine glands except

Accepted Answer

Antidiuretic hormone (ADH) is not secreted by the anterior pituitary. It is secreted by the posterior pituitary and regulates water balance in the body. The other hormones listed (TSH, ACTH, LH, and FSH) are all secreted by the anterior pituitary and control the activities of other endocrine glands in the body.

Question 14

A castaway on a deserted island puts a message in a bottle and throws it into the ocean, hoping it will wash up on some inhabited shore and bring help.In endocrine signaling, the castaway is analogous to a(n)

Accepted Answer

In endocrine signaling, the gland is analogous to the castaway because it releases hormones (messages) into the bloodstream (ocean) in hopes that they will reach and be recognized by the appropriate target cells (inhabited shore) to elicit a response.

Question 15

Which statement about hormone receptors is true?

Accepted Answer

Hormone receptors may be located on either the plasma membrane or within the cell cytoplasm or nucleus. In some cases, the same cell that produces the hormone may also possess receptors for it.

Therefore, options A, B, D, and E are incorrect because they either suggest that all cells respond equally to the same hormone or that the receptors for a hormone are limited to a specific location within the cell.

Question 16

The neurohormones antidiuretic hormone (vasopressin) and oxytocin are produced by the

Accepted Answer

Antidiuretic hormone (vasopressin) and oxytocin are produced by the hypothalamus and released by the posterior pituitary.

Question 17

A castaway on a deserted island puts a message in a bottle and throws it into the ocean, hoping it will wash up on some inhabited shore and bring help.In endocrine signaling, the bottle is analogous to a(n)

Accepted Answer

In endocrine signaling, the "bottle" that carries the message (in this case, the hormone) through the bloodstream to distant target cells is analogous to a carrier molecule. Carrier molecules transport hormones, which are water-insoluble, through the bloodstream to their target sites.

Question 18

Which hormone(s) is/are secreted by the posterior pituitary gland?

Accepted Answer

Oxytocin is one of the two hormones secreted by the posterior pituitary gland, the other being vasopressin (not listed among the options).

Question 19

A castaway on a deserted island puts a message in a bottle and throws it into the ocean, hoping it will wash up on some inhabited shore and bring help.In endocrine signaling, the message is analogous to a(n)

Accepted Answer

In endocrine signaling, hormones are secreted by endocrine cells and travel through the bloodstream to act on target cells. This is similar to a message in a bottle traveling through the ocean until it reaches an inhabited shore.

Question 20

Which statement about hormones, hormone-producing cells, and target cells is true?

Accepted Answer

Target cells have specific receptors for the hormone they are meant to bind to, allowing for a specific response to occur. This is the basis for the specificity of hormone action. The other options are incorrect - endocrine cells can exist as single cells or groups within a tissue, not all hormones travel through the blood (some are paracrine or autocrine), endocrine glands do not have ducts leading outside the body (they secrete into the blood), and proximity to hormone-producing cells does not necessarily determine the strength of the response (receptor density and affinity also play a role).

Quiz 40: Animal Hormones