A. Frogs can reduce water loss by having less porous skin (bags of skin can be eaten to retain moisture)

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1 Name: Biology Review: Amphibians 1-6. Amphibians were the first group of vertebrates to adapt to a land existence. What were three conditions amphibians had to deal with coming on to land and how did they respond to these pressures? (Class lecture) 6 points Condition ( The Problem) Gill filaments need to be kept moist. They would stick together and dry out on land Water provides a buoyant force to support the body. Gravity has a greater effect on organisms that live on land. Extreme temperature changes occur on land, seasonally and even daily Adaptation to that condition ( The Solution) Gills fused together to form a single structure; the lung Strong bones and muscles developed to support the weight Torpor a state of decreased activity in response to extremes in temperature. Hibernation- winter torpor Estivation- summer torpor 7-8. Why are amphibians never completely free of an aquatic life, even though they can survive on land? (See page 804 and Eyewitness: Amphibian pg ) Most species need to keep their skin moist in order to exchange gases with their environment. Also, most species lay their eggs in water where they are fertilized. The tadpole stage is relies on water for its survival. It has gills like a fish, and they feed on aquatic plants Explain three strategies amphibians use to conserve water. (Eyewitness: Amphibian pg.12-13) A. Frogs can reduce water loss by having less porous skin (bags of skin can be eaten to retain moisture) B. Shady places are sought out to avoid dehydration C. Soak up water from wet places and store it in a pouch D. Burrow underground to avoid heat and conserve water in cooler temperatures.

2 The integumentary system (skin) of amphibians has several unique features; list four. (See page 804 an Eyewitness: Amphibian pg. 6) A. Amphibians can breathe through their skin. Gases (O2 and CO2 diffuse across the wet membrane.) B. Permeable skin can lose, or take up water C. Chromatophores produce many color patterns D. Secretions from their skin Features of the Circulatory System (See page 805) Amphibians are the first animal to have a double circulation. What is the difference between pulmonary circulation and systemic circulation? Pulmonary circulation refers to the pathway that deoxygenated blood (coming from all parts of the body) takes from the heart, to the lungs, and back to the heart again. Oxygen is not delivered to your body s cells at any point during pulmonary circulation. Systemic circulation - refers to the pathway that oxygenated blood (fresh from the lungs), moves from the heart, out to the rest of your body, and then back to the heart again. Use the reading on page 805 and Figure 40-8 in your text book to help answer THREE The adult frog has a (20) chambered heart as opposed to fish, which have (21) 21. TWO 22. OXYGENATED (or OXYGEN RICH) The left atrium receives (22) blood from the (23). 23. LUNGS 24. DEOXYGENATED (or OXYGEN POOR) The right atrium receives (24) blood from (25). 25. BODY 26. VENTRICLE Both left and right atria contract at the same time, forcing blood into a single chamber called the (26).

3 Features of the respiratory system (See page 806) Amphibians can exchange gases with their environment through a number of ways. Define pulmonary respiration and cutaneous respiration. Where would an amphibian use each type? Pulmonary respiration Involves using the lungs to exchange O2 and CO2 with environment through inhalation and exhalation. This type of respiration would be used on land. Cutaneous respiration - Exchanging O2 and CO2 through permeable skin. This method would be used while underwater or during hibernation when they are underground Features of the digestive System (See page 807) 31. VOMARINE TEETH Frogs hold onto their prey in two ways. They have two (31) that project from bones in the roof of the mouth and a row of (32) in the upper jaw. 32. MAXILLARY TEETH 33. FRONT A frog s tongue is attached at the (33) of its mouth. (See Eyewitness pg.18-19) 34. Refer to Eyewitness pg Look at the ornate horned frog swallowing that mouse! Why do frogs blink their eyes when they eat? TO HELP THEM SWALLOW FOOD. THE EYES PUSH DOWN ON THE ROOF OF THE MOUTH AND FORCE FOOD DOWN THE ESOPHOGUS 35. CLOACA or VENT The (35) is a cavity at the posterior end of amphibians through which waste products, eggs, and sperm cells pass through. John & Chloe Features of the external anatomy and sense organs (See page 809) Unlike fish, amphibians have eyelids to protect their eyes against dirt and dehydration. Frogs also have a third eyelid called the (36). 36. NICTITATING MEMBRANE 37. TYMPANIC MEMBRANES Frogs have no external ears ( known as pinnae). Instead they have thin eardrums or (37) located on the surface of the skin just behind the eyes. 38. Why is it important that the frog is able to hear well? FROGS NEED TO HEAR WELL SO THEY CAN PICK UP THE MATING CALLS SPECIFIC TO THEIR OWN KIND.

4 Features of the reproductive system, growth and development (see pages 810 and 811 and Eyewitness Amphibian pages 23-26) 39. NUPTIAL (NUP-CHOO-UL) PADS On male frogs, the inner toes are enlarged into structures called (39) which are used during the breeding season to clasp the female. 40. AMPLEXUS In frogs, sex has a special term known as (40), whereby the females eggs are fertilized by the male. 41. METAMORPHOSIS The change from tadpole to adult frog is called (41) What are the changes that a tadpole goes through during its metamorphosis? A. THE TAIL IS ABSORBED. LIMBS GROW OUT FROM THE BODY. B. THE MOUTH BROADENS, DEVELOPING SMALL TEETH AND JAWS C. LUNGS DEVELOP, REPLACING GILLS D. THE HEART DEVELOPS A THIRD CHAMBER, PARTIALLY SEPARATING O2 RICH BLOOD FROM O2 POOR BLOOD 46. Young amphibians are like fish, in that they (A) are gill breathers (B) live partially on land (C) have pectoral fins (D) absorb oxygen from the air 47. The following are typical of amphibians except (A) internal fertilization B) thin, wet, smooth skin (C) webbed feet (D) vegetarian youngsters 48. Amphibians can be found in (A) wet environments (B) dry environments (C) hot environments (D) cold environments (E) All of these 49. Frogs and toads differ from salamanders, in that salamanders have (A) claws (B) lungs (C) gills (D) tails 50. Toads, unlike frogs (A) cause warts (B) eat insects and worms (C) don t lay their eggs inn water (D) are better adapted to life on land 51. Frogs survive periodic drying of their ponds by (A) burrowing underground (B) laying dormant eggs (C) decreasing their activity (D) A and C 52. The male frog attracts the female (A) with a box of flies (B) by releasing pheromones (C) with vocal calls (D) by driving a fast car 53. The well developed structure responsible for hearing is the (A) glottis (B) eustachian tube (C) tympanic membrane (D) cloaca 54. To ensure the healthy survival of amphibians, we need to (A) reduce water and air pollution (C) educate ourselves about them (B) preserve key habitat locations (D) all of the above

5 Nature: The Toadskin Spell 1. Titikaka Frog- Has folds of skin to increase surface area to absorb O 2. Also does pushups to increase the flow of water over the skin. 2. Jesus Christ Frog- uses the surface tension of water a trampoline to propel itself across a body of water. 3. Horned Toad camouflages itself using mimicry strategies. Looks like leaves. 4. Tomato Frog - Inflates itself to avoid being eaten. It also secretes a sticky substance that gums of the jaws of a would be predator. 5. Caine Toad Introduced from South America to eat beetles plaguing sugar cane fields, they ate everything but the beetles, causing a population explosion. They pose a threat to native wildlife by outcompeting them for resources and are poisonous. 6. Poison Arrow Frogs a poison from the frog s skin is used by natives to coat their blow darts. They advertise their toxicity with flamboyant colors. 7. African Clawed Toad chemicals from their skin are used as antibiotics and cancer treatments. 8. African Bull Frog Battles other frogs for breeding privileges. Can detects offspring with chemical signals. Males are much larger than females. Helps tadpoles to water.

6 9. Gray Tree Frog- Builds its nest in the trees. Male and female mix their sperm / eggs in a frothy substance that hardens in the sun. Nourished by the yolk within, the tadpoles drop into the water, as their cover melts. 10. Marsupial Frog - Has a pouch on its back. The young develop in this pouch and are set free when the mother opens the pouch with her rear legs. 11. Surinam Toad - Has a spongy layer of skin on its back where tadpoles complete their metamorphosis. 12. The Water Holding Frog Can hold 2/3 of its body weight in water to deal with long droughts. 13. Breviseps - Desert dwelling amphibian. Buries itself in the sand to avoid the heat. Skin soaks up water from the sand. Lays its eggs on top of the sand surrounded by a protective layer of unfertilized eggs 14. African Sun Worshiper At a certain temperature the skin turns white to reflect the rays of the sun. 15. Canadian Tree Frog Can freeze itself solid during the winter. Metabolism and breathing slow down to almost nothing. Finding out how they do this could help find a way to preserve organs for transplantation. 16. Red Eyed Tree Frog Breed in large congregations. Their populations are doing well. 17. How can we benefit form frogs and toads? Several medical applications can be derived from their skin; antibiotics, antiviral agents, fungicides and cancer treatments. Also the Canadian Gray Tree Frog may lead to being able to freeze and thaw living

7 tissue. 18. How do amphibians function as indicators of environmental health? Because amphibians start their life in water and spend their adult life in water, air and land, their permeable skin is susceptible to pollution, increased UV rays and other threats. (similar to a barometer predicting on oncoming storm) 19. Why should we be concerned with declining amphibian populations? Their declining populations may be an early indicator that something is wrong in the environment. While humans have more protection it may be only a matter of time before what affects them, affects us. They also provide medical benefits we may never know about if they continue to disappear.

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