Deck 32: Animals: Part II

Question 1

Which of these is not a chordate characteristic?

A) dorsal supporting rod, the notochord
B) dorsal tubular nerve cord
C) pharyngeal pouches
D) postanal tail
E) vertebral column

Answer 1

The supporting rod on the dorsal side just below the nerve cord is called as notochord which is one of the characteristic of chordate.
Hence, the option (a) is incorrect.
The tubular nerve cord on the dorsal side is one of the characteristic of chordate. The nerve cord contains canal which is filled with fluid.
Hence, the option (b) is incorrect.
Pharyngeal pouches are present only during the embryonic development in most vertebrates. In non vertebrate chordate, like fishes and amphibians it is developed into functional gills. It is one of the characteristic of chordate.
Hence, the option (c) is incorrect.
Postanal tail is a tail which extends beyond the anus and it is one of the characteristic of chordate.
Hence, the option (d) is incorrect.
The embryonic notochord is replaced by the vertebral column in vertebrates during development and it is not the characteristic of chordate, it is the characteristic of vertebrates.
Hence, the option is correct.

Question 2

Label the diagram of a chordate below:

Answer 2

The diagram of a chordate is labeled as below:
a. : These are present only during the embryonic development in most vertebrates. In non vertebrate chordate, like fishes and amphibians it is developed into functional gills.
b. : The tubular nerve cord on the dorsal side is one of the characteristic of chordate. The nerve cord contains canal which is filled with fluid.
c. : The supporting rod on the dorsal side just below the nerve cord is called as notochord.
d. : It is a tail which extends beyond the anus and it is one of the characteristic of chordate.

Question 3

Which of these is not characteristic of all vertebrates?

A) complete digestive system
B) closed circulatory system
C) skin with either scales or feathers
D) endoskeleton made of bone or cartilage
E) vertebral column

Answer 3

The complete digestive system and a large coelom is the characteristic of vertebrates.
Hence, the option (a) is incorrect.
In vertebrates, the blood is present completely within blood vessels. They have closed type of circulatory system.
Hence, the option (b) is incorrect.
The endoskeleton which is strong and jointed is the characteristic of vertebrates. It is made up of bone (in Bony fishes) or cartilage (in cartilaginous fishes).
Hence, the option (d) is incorrect.
The embryonic notochord is replaced by the vertebral column with individual vertebrae in vertebrates during development and it is the characteristic of vertebrates.
Hence, the option (e) is incorrect.
Reptiles have skin with either scales or feathers. So it is the characteristic of reptiles but not vertebrates.
Hence, the option is correct.

Question 4

The first vertebrates to evolve were

A) amphibians.
B) jawed fishes.
C) jawless fishes.
D) amniotes.
E) reptiles.

Question 5

Bony fishes are divided into which two groups?

A) hagfishes and lampreys
B) sharks and ray-finned fishes
C) ray-finned fishes and lobe-finned fishes
D) jawless fishes and cartilaginous fishes

Question 6

Amphibians evolved from what type of ancestral fish?

A) sea squirts and lancelets
B) ray-finned fishes
C) cartilaginous fishes
D) lobe-finned fishes
E) jawless fishes

Question 7

The amniotes include all but the

A) birds.
B) reptiles.
C) mammals.
D) amphibians.

Question 8

Which of the following groups has a heart with four distinct chambers?

A) birds
B) lampreys
C) reptiles other than birds
D) amphibians

Question 9

The first mammals to evolve were

A) aquatic.
B) placental.
C) marsupials.
D) primates.
E) monotremes.

Question 10

Choose the correct order of primate evolution, from the oldest to the most recent group.

A) prosimians-anthropoids-hominoids-hominids-hominines
B) hominines-hominids-hominoids-anthropoids-prosimians
C) prosimians-anthropoids-hominines-hominids-hominoids
D) anthropoids-hominines-hominids-hominoids-prosimians
E) None of the above are correct.

Question 11

The fossil nicknamed Lucy was a(n)

A) early Homo.
B) australopith.
C) ardipithecine.
D) modern human.

Question 12

This genus are the direct ancestors of the genus Homo.

A) Ardipithecus
B) Sahelanthropus
C) Australopithecus
D) Denisovans
E) None of these are correct.

Question 13

Which species was probably the first of the genus Homo to migrate from Africa?

A) Homo erectus
B) Homo habilis
C) Denisovans
D) Homo florensiensis
E) None of these are correct.

Question 14

According to the fossil record, which of these species is the earliest of the Homo genus?

A) H. sapiens
B) H. erectus
C) H. habilis
D) H. heidelbergensis
E) H. ergaster

Question 15

According to the replacement model, Homo sapiens

A) was the first to migrate from Africa.
B) is the earliest species of the genus Homo.
C) followed earlier Homo species out of Africa.
D) originated in the New World.
E) None of these are correct.

Question 16

Vertebrates and Human Medicine
Hundreds of pharmaceutical products come from other vertebrates, and even those that produce poisons and toxins provide medicines that benefit us.
Natural Products with Medical Applications
The black-and-white spitting cobra of Southeast Asia paralyzes its victims with a potent venom, which eventually leads to respiratory arrest. However, that venom is also the source of the drug Immunokine, which can inhibit some harmful effects of an overactive immune system. It is approved in Thailand for use in combating the side effects of cancer therapy, and it is being studied for use in treating AIDS, autoimmune diseases, and other disorders.
Although snakebites can be very painful, certain components found in venom actually relieve pain. The black mamba, found mainly in sub-Saharan Africa, is one of the most lethal snakes on Earth. Compounds in its venom called mambalgins, however, block pain signals by inhibiting the flow of certain ions through nerves that carry pain messages. When tested in mice, these compounds were as effective as morphine, with fewer side effects.
Another compound, known as epibatidine, derived from the skin of an endangered Ecuadorian poison-dart frog, is 50-200 times more powerful than morphine in relieving chronic and acute pain, without the addictive properties. Unfortunately, it can also have serious side effects, so companies have synthesized compounds with a similar structure, hoping to improve its safety profile.
Other venoms mainly affect blood clotting. Eptifibatide is derived from the venom of the pigmy rattlesnake, which lives in the southeastern United States. Because it binds to blood platelets and reduces their tendency to clump together, this drug is used to reduce the risk of clot formation in patients at risk for heart attacks. Alternatively, the venom of several pit vipers, such as the copperhead, contains "clotbusting" (thrombolytic) substances, which can be used to dissolve abnormal clots that have already formed.
Sharks produce a variety of chemicals with potentially medicinal properties. Squalamine is a steroidlike molecule that was first isolated from the liver of dogfish sharks. It has broad antimicrobial properties, and it can inhibit the abnormal growth of new blood vessels, which is a factor in cancer and a variety of other diseases. Squalamine is also safe enough to be used in the eye and is currently being tested as a potential treatment for macular degeneration, an eye disease that will affect 3 million Americans by 2020.
Animal Pharming
Some of the most powerful applications of genetic engineering can be found in the development of drugs and therapies for human diseases. In fact, this technology has led to a new industry: animal pharming, which uses genetically altered vertebrates, such as mice, sheep, goats, cows, pigs, and chickens, to produce medically useful pharmaceutical products.
To accomplish this, the human gene for some useful product is inserted into the embryo of a vertebrate. That embryo is implanted into a foster mother, which gives birth to the transgenic animal, which contains genes from the two sources. An adult transgenic vertebrate produces large quantities of the pharmed product in its blood, eggs, or milk, from which the product can be easily harvested and purified.
An example of a pharmed product used in human medicine is human antithrombin. This medication is important in the treatment of individuals who have a hereditary deficiency of this protein and so are at high risk for lifethreatening blood clots. Approved by the FDA in 2009, the bioengineered drug, known by the brand name ATryn®, is purified from the milk of transgenic goats.
Xenotransplantation
There is an alarming shortage of human donor organs to fill the need for hearts, kidneys, and livers. One solution is xenotransplantation, the transplantation of nonhuman vertebrate tissues and organs into humans. The first such transplant occurred in 1984 when a team of surgeons implanted a baboon heart into an infant, who, unfortunately, lived only 20 days.
Although apes are more closely related to humans, pigs are considered to be the best source for xenotransplants. Pig organs are similar to human organs in size, anatomy, and physiology, and large numbers of pigs can be produced quickly. Most infectious microbes of pigs are unlikely to infect a human recipient. Currently, pig heart valves and skin are routinely used for treatment of humans. Miniature pigs, whose heart size is similar to that of humans, are being genetically engineered to make their tissues less foreign to the human immune system, to minimize rejection.
Figure 32A Medical uses of animals. a. Snake venom may be used to create pain medications. b. Mammals, such as these goats, may express pharmaceutical compounds in their milk. c. Pigs are now being genetically altered to provide a supply of hearts for heart transplant operations.
Is it ethical to change the genetic makeup of vertebrates in order to use them as drug or organ factories?

Question 17

Vertebrates and Human Medicine
Hundreds of pharmaceutical products come from other vertebrates, and even those that produce poisons and toxins provide medicines that benefit us.
Natural Products with Medical Applications
The black-and-white spitting cobra of Southeast Asia paralyzes its victims with a potent venom, which eventually leads to respiratory arrest. However, that venom is also the source of the drug Immunokine, which can inhibit some harmful effects of an overactive immune system. It is approved in Thailand for use in combating the side effects of cancer therapy, and it is being studied for use in treating AIDS, autoimmune diseases, and other disorders.
Although snakebites can be very painful, certain components found in venom actually relieve pain. The black mamba, found mainly in sub-Saharan Africa, is one of the most lethal snakes on Earth. Compounds in its venom called mambalgins, however, block pain signals by inhibiting the flow of certain ions through nerves that carry pain messages. When tested in mice, these compounds were as effective as morphine, with fewer side effects.
Another compound, known as epibatidine, derived from the skin of an endangered Ecuadorian poison-dart frog, is 50-200 times more powerful than morphine in relieving chronic and acute pain, without the addictive properties. Unfortunately, it can also have serious side effects, so companies have synthesized compounds with a similar structure, hoping to improve its safety profile.
Other venoms mainly affect blood clotting. Eptifibatide is derived from the venom of the pigmy rattlesnake, which lives in the southeastern United States. Because it binds to blood platelets and reduces their tendency to clump together, this drug is used to reduce the risk of clot formation in patients at risk for heart attacks. Alternatively, the venom of several pit vipers, such as the copperhead, contains "clotbusting" (thrombolytic) substances, which can be used to dissolve abnormal clots that have already formed.
Sharks produce a variety of chemicals with potentially medicinal properties. Squalamine is a steroidlike molecule that was first isolated from the liver of dogfish sharks. It has broad antimicrobial properties, and it can inhibit the abnormal growth of new blood vessels, which is a factor in cancer and a variety of other diseases. Squalamine is also safe enough to be used in the eye and is currently being tested as a potential treatment for macular degeneration, an eye disease that will affect 3 million Americans by 2020.
Animal Pharming
Some of the most powerful applications of genetic engineering can be found in the development of drugs and therapies for human diseases. In fact, this technology has led to a new industry: animal pharming, which uses genetically altered vertebrates, such as mice, sheep, goats, cows, pigs, and chickens, to produce medically useful pharmaceutical products.
To accomplish this, the human gene for some useful product is inserted into the embryo of a vertebrate. That embryo is implanted into a foster mother, which gives birth to the transgenic animal, which contains genes from the two sources. An adult transgenic vertebrate produces large quantities of the pharmed product in its blood, eggs, or milk, from which the product can be easily harvested and purified.
An example of a pharmed product used in human medicine is human antithrombin. This medication is important in the treatment of individuals who have a hereditary deficiency of this protein and so are at high risk for lifethreatening blood clots. Approved by the FDA in 2009, the bioengineered drug, known by the brand name ATryn®, is purified from the milk of transgenic goats.
Xenotransplantation
There is an alarming shortage of human donor organs to fill the need for hearts, kidneys, and livers. One solution is xenotransplantation, the transplantation of nonhuman vertebrate tissues and organs into humans. The first such transplant occurred in 1984 when a team of surgeons implanted a baboon heart into an infant, who, unfortunately, lived only 20 days.
Although apes are more closely related to humans, pigs are considered to be the best source for xenotransplants. Pig organs are similar to human organs in size, anatomy, and physiology, and large numbers of pigs can be produced quickly. Most infectious microbes of pigs are unlikely to infect a human recipient. Currently, pig heart valves and skin are routinely used for treatment of humans. Miniature pigs, whose heart size is similar to that of humans, are being genetically engineered to make their tissues less foreign to the human immune system, to minimize rejection.
Figure 32A Medical uses of animals. a. Snake venom may be used to create pain medications. b. Mammals, such as these goats, may express pharmaceutical compounds in their milk. c. Pigs are now being genetically altered to provide a supply of hearts for heart transplant operations.
What are some of the health concerns that may arise due to xenotransplantation?

Question 18

Human Ethnic Groups
Evolutionists have hypothesized that human variations evolved as adaptations to local environmental conditions. One obvious difference among people is skin color. A darker skin is protective against the high UV intensity of bright sunlight. On the other hand, a white skin ensures vitamin D production in the skin when the UV intensity is low. Harvard University geneticist Richard Lewontin points out, however, that this hypothesis concerning the survival value of dark and light skin has never been tested.
Two correlations between body shape and environmental conditions have been noted since the nineteenth century. The first, known as Bergmann's rule, states that animals in colder regions of their range have a bulkier body build. The second, known as Allen's rule, states that animals in colder regions of their range have shorter limbs, digits, and ears. Both of these effects help regulate body temperature by increasing the surface-area-to-volume ratio in hot climates and decreasing the ratio in cold climates. For example, Figure 32B, shows that the Maasai of East Africa tend to be slightly built with elongated limbs, while the Eskimos, who live in northern regions, are bulky and have short limbs.
Other anatomical differences among ethnic groups, such as hair texture, a fold on the upper eyelid (common in Asian peoples), and the shape of lips, cannot be explained as adaptations to the environment. Perhaps these features became fixed in different populations due simply to genetic drift. As far as intelligence is concerned, no significant disparities have been found among different ethnic groups.
Genetic Evidence for Common Ancestry
The replacement model for the evolution of humans, discussed earlier in this section, pertains to the origin of ethnic groups. This hypothesis proposes that all modern humans have a relatively recent common ancestor-that is, Cro-Magnon-who evolved in Africa and then spread into other regions. Paleontologists tell us that the variation among modern populations is considerably less than existed among archaic human populations some 250,000 years ago. If so, all ethnic groups evolved from the same single ancestral population.
A comparative study of mitochondrial DNA shows that the differences among human populations are consistent with their having a common ancestor no more than a million years ago. Lewontin has also found that the genotypes of different modern populations are extremely similar. He examined variations in 17 genes, including blood groups and various enzymes, among seven major geographic groups: Europeans (caucasians), black Africans, mongoloids, South Asian Aborigines, Amerinds, Oceanians, and Australian Aborigines. He found that the great majority of genetic variation-85%-occurs within ethnic groups, not between them. In other words, the amount of genetic variation between individuals of the same ethnic group is greater than the variation between any two ethnic groups.
Figure 32B Human ethnic groups. a. The Maasai live in East Africa. b. Eskimos live near the Arctic Circle.
Why might a person's outward appearance not necessarily be an indication of their ethnic background?

Question 19

Human Ethnic Groups
Evolutionists have hypothesized that human variations evolved as adaptations to local environmental conditions. One obvious difference among people is skin color. A darker skin is protective against the high UV intensity of bright sunlight. On the other hand, a white skin ensures vitamin D production in the skin when the UV intensity is low. Harvard University geneticist Richard Lewontin points out, however, that this hypothesis concerning the survival value of dark and light skin has never been tested.
Two correlations between body shape and environmental conditions have been noted since the nineteenth century. The first, known as Bergmann's rule, states that animals in colder regions of their range have a bulkier body build. The second, known as Allen's rule, states that animals in colder regions of their range have shorter limbs, digits, and ears. Both of these effects help regulate body temperature by increasing the surface-area-to-volume ratio in hot climates and decreasing the ratio in cold climates. For example, Figure 32B, shows that the Maasai of East Africa tend to be slightly built with elongated limbs, while the Eskimos, who live in northern regions, are bulky and have short limbs.
Other anatomical differences among ethnic groups, such as hair texture, a fold on the upper eyelid (common in Asian peoples), and the shape of lips, cannot be explained as adaptations to the environment. Perhaps these features became fixed in different populations due simply to genetic drift. As far as intelligence is concerned, no significant disparities have been found among different ethnic groups.
Genetic Evidence for Common Ancestry
The replacement model for the evolution of humans, discussed earlier in this section, pertains to the origin of ethnic groups. This hypothesis proposes that all modern humans have a relatively recent common ancestor-that is, Cro-Magnon-who evolved in Africa and then spread into other regions. Paleontologists tell us that the variation among modern populations is considerably less than existed among archaic human populations some 250,000 years ago. If so, all ethnic groups evolved from the same single ancestral population.
A comparative study of mitochondrial DNA shows that the differences among human populations are consistent with their having a common ancestor no more than a million years ago. Lewontin has also found that the genotypes of different modern populations are extremely similar. He examined variations in 17 genes, including blood groups and various enzymes, among seven major geographic groups: Europeans (caucasians), black Africans, mongoloids, South Asian Aborigines, Amerinds, Oceanians, and Australian Aborigines. He found that the great majority of genetic variation-85%-occurs within ethnic groups, not between them. In other words, the amount of genetic variation between individuals of the same ethnic group is greater than the variation between any two ethnic groups.
Figure 32B Human ethnic groups. a. The Maasai live in East Africa. b. Eskimos live near the Arctic Circle.
Some ethnic groups are more highly disposed to certain diseases than others, such as hypertension and cardiovascular disease. Explain what factors may have contributed to this in this ethnic population.