Here are the answers to your assignment questions: 1. Differentiate between mammals and aves in terms of their excretion Mammals excrete urea* as their primary nitrogenous waste, which is dissolved in water and eliminated as urine through kidneys and a urinary bladder. Aves (birds) excrete uric acid*, a semi-solid paste that requires very little water for elimination, helping them conserve water. They lack a urinary bladder. 2. Differentiate between Chondrichthyes and osteichthyes Chondrichthyes (cartilaginous fish like sharks and rays) have skeletons made entirely of cartilage, possess placoid scales*, and typically use internal fertilization. Osteichthyes (bony fish like salmon and tuna) have skeletons made of bone, possess cycloid or ctenoid scales*, and mostly use external fertilization. 3. Differentiate between monotremes and placental mammals Monotremes (e.g., platypus, echidnas) are unique mammals that lay eggs and possess a cloaca* (a single opening for waste and reproduction). Placental mammals give birth to live young that develop extensively inside the mother's uterus, nourished by a placenta*, and have separate openings for waste and reproduction. 4. What is the difference between oviparous and viviparous Oviparous animals lay eggs*, and the embryonic development occurs outside the mother's body. Viviparous animals give birth to live young*, with the embryo developing inside the mother's body and receiving nourishment directly from her. 5. Differentiate between placoid and cycloid scale Placoid scales* are found in cartilaginous fish (Chondrichthyes). They are structurally similar to teeth, with a central pulp cavity, dentin, and an enamel-like outer layer, giving the skin a rough texture. Cycloid scales* are found in some bony fish (Osteichthyes). They are thin, flexible, and have a smooth, rounded outer edge, growing in concentric rings that show growth lines. 6. Enumerate 5 biological advancement of the amphibians over the fishes 1. Development of limbs (tetrapod locomotion) for movement on land. 2. Presence of lungs for breathing air, supplementing skin respiration. 3. A more efficient three-chambered heart for better blood circulation. 4. Evolution of eyelids and tear glands to keep eyes moist and protected on land. 5. Development of a tympanic membrane (eardrum) and columella for hearing in air. 7. Itemize 5 adaptation of Animal transition from water to land 1. Evolution of lungs for gaseous exchange in an air environment. 2. Development of a stronger skeletal system to support body weight against gravity. 3. Transformation of fins into limbs for locomotion on solid ground. 4. Adaptations of the skin to prevent desiccation (drying out). 5. Development of internal fertilization to protect gametes from drying out. 8. State 5 similarities between reptiles and viruses While reptiles are complex multicellular organisms and viruses are non-cellular infectious agents, here are some very general, abstract similarities: 1. Both possess genetic material (DNA for reptiles, DNA or RNA for viruses) that carries hereditary information. 2. Both undergo a process of replication or reproduction to create new copies of themselves. 3. Both are subject to evolution and natural selection, leading to changes in their populations over time. 4. Both can interact with host organisms (reptiles as hosts for parasites/pathogens, viruses as parasites of hosts). 5. Both have a defined structure (though vastly different in complexity and composition). 9. Explain two characteristics of mammals supremacy over reptiles 1. Endothermy (Warm-bloodedness): Mammals can maintain a constant, high internal body temperature through metabolic processes, allowing them to be active in a wider range of environments and times compared to ectothermic (cold-blooded) reptiles. 2. Advanced Parental Care and Brain Development: Mammals typically exhibit extensive parental care, nurturing and teaching their young, which contributes to higher survival rates and the development of complex behaviors. They also possess highly developed brains, leading to greater intelligence and adaptability. 10. Enumerates 5 reasons why monotremes and marsupials are special group of mammals compared to the placental mammals 1. Reproductive Strategy: Monotremes lay eggs, and marsupials give birth to highly undeveloped young that complete development externally, unlike placental mammals with their long internal gestation. 2. Pouch (Marsupium): Marsupials possess a marsupium (pouch) where their altricial young continue development, a feature absent in placental mammals. 3. Cloaca (Monotremes): Monotremes have a cloaca, a single opening for digestive, urinary, and reproductive tracts, a primitive feature not found in placental mammals. 4. Mammary Glands without Nipples (Monotremes): Monotremes secrete milk directly onto their skin from mammary glands, which the young lap up, rather than through nipples as in other mammals. 5. Rudimentary Placenta (Marsupials): Marsupials have a less developed yolk sac placenta compared to the complex chorioallantoic placenta of placental mammals, resulting in a shorter gestation period.