What are the five features of the chordates? A hollow dorsal nerve cord Just beneath the dorsal surface of the animal. In vertebrates this differentiates into the brain and spinal cord. ; A flexible rod called the notched that’s on the dorsal side of the primitive gut in the early embryo, present at some developmental stage in all chordates, located Just below the nerve cord. May persist in some chordates; in others, it is replaced by the vertebral column that forms around the nerve cord. Mainly for movement and support) ; Pharyngeal lilts connect the pharynx with the external environment. Terrestrial vertebrates have pharyngeal pouches. These are present in the embryos of all vertebrates. They BECOME slits, open to the outside in animals with gills. ; A post anal tail which extends beyond the anus, at least during their embryonic development. Nearly all other animals have a terminal anus. ; An Endlessly which is a longitudinal ciliated groove on the ventral wall of the pharynx which produces mucus to gather food particles found in orchestrate and spectrophotometer. 2.
Do all chordates have all of these five features at all life stages? Give examples where they do not. No. For example, the post anal tail exists only during embryonic development in some vertebrates. The notched may persist in some chordates while in others, it is replaced by the vertebral column that forms around the nerve cord. Pharyngeal slits are exclusive to vertebrates that breathe underwater. All chordates have these features at some point in their lives. 3. Which chordate features are present in adult denunciates? Which are missing in adults? Why are denunciates chordates if the adults are missing key chordate features?
Adult denunciates have pharyngeal slits and nematodes to trap microscopic food particles. The post anal tail, the nerve cord and the notched are lost. They are still chordates because, as larvae, denunciates had these key chordate features. 4. What is the function of the endlessly? See question 1. 5. How might larval denunciates have given rise to the vertebrates? They plainly exhibit all the features of chordates, which all vertebrates have, and this makes them the common ancestor. A theory of vertebrate origin involves this larval denunciate which acquired the ability to reproduce. . What is the function of pharyngeal slits in nacelles (Spectrophotometer)? The slits provide an exit for water and are an adaptation for filter feeding. 7. What are the five seismographs of vertebrates? A vertebral column A Head A Neural Crest- A unique group of embryonic cells that contributes to the development of many vertebrate structures. ; Internal organs Endorsements 8. What is the main advantage of bone over chitin (or calcium carbonate) skeletons? Bone is a dynamic, living tissue that is strong without being brittle, providing better support and protection. . What does an internal skeleton allow vertebrates to do? It allows them to reach great sizes and give them extraordinary powers of movement. 10. Why are “fish” and “reptiles” paralytic groups? What does that mean? They are paralytic groups because not all the descendants have been recorded because some fish are more closely related to other vertebrates than they are to other fish. Similarly, some reptiles are more closely related to birds than other reptiles. 11. Describe the features of early vertebrates prior to the evolution of jaws.
Early vertebrates, the first fishes for example, did not have teeth or Jaws and instead had only a mouth at the front end of the body that could be opened to take in food. 12. What are the five features of “fish”? Vertebral column- Bony or cartilaginous spine surrounding the dorsal nerve cord and a bony or cartilaginous skull encasing the brain. ; Jaws and paired fins ; Internal gills- Allows flow of water through the mouths and across the gills to breathe. 13. What are the two living groups of Jailers fishes? Lampreys and Hagfish. 14. From what previously existing structures did Jaws evolve?
Jaws evolved from the most anterior of a series of arch-supports made of cartilage, which were used to enforce the tissue between gill slits to hold the gill slits open. 15. What are the three major groups of Eccentricities? Sharks, skates and rays. 16. What is the difference between bone and the calcified cartilage of contraindications? Calcified cartilage is cartilage, but strengthened by granules of calcium carbonate deposited in its outer layers. Bone is made up of crystals of calcium phosphate salt. 17. From what previously existing structures did teeth evolve? In early sharks, teeth evolved from rough scales on the skin. 8. What is the function of a swim bladder? What group has it and why? What are two ways of getting gas into it? A swim bladder is a gas filled sac that allows them to regulate their buoyancy density which allows the animal to remain suspended at any depth of water effectively. Bony fishes have it because their bones make them less buoyant. 19. What is an propeller? What group has it? What is a goldfish doing when it seems to be gulping water in a tank? The propeller is a hard plate that covers gills on each side of the head and flexing it allows bony fishes to pump water over their gills.
When the mouth of the goldfish is opened, closing the propeller increases the illume of the mouth cavity, so that water is drawn into the mouth. 20. What are the major differences in fin structure between ray-finned and lobe-finned fishes? Which group made it to land? In ray finned fishes, the internal skeleton of the fin is composed of parallel bony rays that support and stiffen each fin. They contain no muscles and are rather moved by muscles within the body. In contrast, lobe finned fishes have paired fins that consist of a long fleshy muscular lobe, supported by a central core of bones that form fully articulated Joints with one another.
There are non rays only at the tips of each lobed fin. 21 . What are the three major groups of amphibians? Anural Caudate Peapod 22. What are the five distinguishing features of amphibians? ; Legs ; Lungs Coetaneous respiration-Respire through skin; require moist skin ; Pulmonary veins Partially divided heart-prevents aerated blood from the lungs from mixing with non-aerated blood. 23. What does it mean to have two paths for circulation? How does this differ from the single circuit in fish circulation? It refers to a pulmonary and systemic path. Fish circulation is not like this since blood is pumped from the heart to he gills.
It is not separated. 24. What are the five major challenges to life on land and how did early amphibians solve these problems? ; Supporting large size and body weight on land that was facilitated in a water environment. ; Structure of fish gills requires buoyancy of water to support it and do not function in air. Other forms of obtaining oxygen were required. ; Delivering big amounts of oxygen to larger muscle required modifications to heart and circulatory system. ; Reproduction still had to be carried out in the water so eggs don’t dry out. ; Body itself have to be reverted from drying out. 25.
How did the fins of lobe-finned fishes evolve into legs? Libertines fishes have muscular lobes with bones connected by Joints which evolved into limbs capable of movement on land. 26. What are the three main characteristics of “reptiles”? How does each of these features meet the challenges of life on land listed above? ; Amniotic eggs- Lay eggs containing 4 membranes (yolk sac, amnion, Illinois and chorizo. ); same as birds and mammals. Watertight shell prevents them from drying out. ; Dry skin- Dry, watertight skin to prevent water loss. Thoracic breathing-Expand and contract rib cage to suck air into lung and then force it out.
Limits breathing capacity to volume of lungs, adaptation to air breathing. 27. What groups are included in the amniotic? What feature unites them? Birds, mammals and reptiles. They all can lay amniotic eggs with the 4 membranes inside mentioned above. 28. What is the purpose of the fetal membranes? What are the four fetal membranes and what are their functions? Fetal membranes make the egg an independent life system. The chorizo is the outermost membrane of the egg, Just uneaten the shell and allows exchange of respiratory gases, but retains water. The amnion encases the developing embryo within a fluid filled cavity.
The yolk sac provides food from the yolk for the embryo via blood vessels connecting to its gut and finally the Illinois surrounds a cavity into which waste products from the embryo are excreted. 29. What is the function of temporal holes? How do they differ in synapses as compared to diapers? What class of vertebrates arose from synapses? Temporal holes were holes behind the openings of the eyes that reptilian Jaws were anchored o so that they could bite more powerfully. Synapses had only a pair of temporal holes while diapers had two pairs. Mammals arose from synapses. 0. What groups of diapers are orchards? Crocodiles, pterosaurs, dinosaurs and birds. From what group to dinosaurs Christian. Did birds evolve? 32. How does the reptilian heart differ from the amphibian heart? It provides oxygen to the body more efficiently. The septum is extended within the heart from the atrium partway across the ventricle, creating a partial wall so that less oxygen poor blood is mixed with oxygen rich blood. In crocodiles, the septum completely vides the ventricle, creating a four-chambered heart, Just like in birds and mammals. 33.
What are the four living groups of reptiles? Echelons: Turtles and tortoises Ornithological: Tartars Summate: Lizards and snakes Crocodilian: Crocodiles and alligators 34. What are the two distinguishing features of birds and how are they related to flight? ; Feathers: Provide lift for flight Flight skeleton: Bones are thin and hollow which allow for flight. 35. What physiological demands arise from flight in birds and what modifications to the respiratory and circulatory systems help to meet these demands? Flight muscles consume a lot of oxygen during active flight.
To solve this problem, birds are designed so that when they inhale, air goes past the lungs to a series of air sacs located near and within the hollow bones of the back; from there, air travels to the lungs and then a set of anterior air sacs before being exhaled. Because air passes all the way through the lungs in a single direction, gas exchange is highly efficient. Birds require a very high metabolism to power active flight so very efficient blood circulation is needed. Birds have a four chambered heart so the two blood recirculation do not mix, bringing fully oxygenated blood to the flight muscles. 6. What are the four features of mammals? Hair ; Mammary glands- Females have mammary glands that secret milk ; Endothermic- Organism can maintain body temperature Placenta-specialized organ that brings the bloodstream of the fetus into close contact with the bloodstream of the mother so that she provides the baby with water, food and oxygen. 37. What are the four functions of hair? Regulate body temperature Camouflage Sensory structures (such as cat whiskers) Defensive weapons (such as porcupine quills) 38. What is so special about mammals’ teeth? They are not all the same.
Mammals have different types of teeth that are highly specialized to match their diets. 39. What are the three groups of mammals? How do they differ? They differ in how their young develop ; Metronomes- Mammals that lay eggs ; Marsupials-pouched mammals (young continues development after birth in these pouches ; Placental Mammals-development of embryo forms in uterus, dependent on placenta From what group to mammals did humans arise? Placental mammals. 41 . What are the two major features of primates and how are they related to arability (living in trees)? Grasping fingers and toes (better grasp of trees and vines) ; Binocular vision (Helps mammals Judge distance precisely which is important for animals moving through trees) 42. What are the three living groups of promising? Lemurs Lorries Tarsier 43. What are the three living groups of anthropoids? ; New World Monkeys Old World Monkeys Hominids 44. Who are the hominids? From which group of monkeys did they arise? Apes and hominids (humans). From the Old World monkeys. 45. What is the defining characteristic of hominids? What changes in leg