BIO1102 Introduction to Biology & Ecology of Living Organisms 2024/2025 PDF

BIO1102 – Introduction to the Biology and Ecology of Living Organisms. ACADEMIC YEAR: 2024/2025 LECTURER: Dr. Arianne-Elise Harris PROPERTIES AND DIVERSITY OF ANIMALS What do we consider as an “Animal” ? The first Four characteristics. 1. Animals are a kingdom of mult...

BIO1102 – Introduction to the Biology and Ecology of Living Organisms. ACADEMIC YEAR: 2024/2025 LECTURER: Dr. Arianne-Elise Harris PROPERTIES AND DIVERSITY OF ANIMALS What do we consider as an “Animal” ? The first Four characteristics. 1. Animals are a kingdom of multicellular organisms. Eukaryotic. Have a nucleus and other membrane-bound organelles 2. They are Heterotrophs. 1. They cannot make their own food but instead get nutrients by eating other living things. 3. Undergo cell specialization: organisms develop via cell diversification (stem cells) to facilitate different bodily functions Lack a cell wall but can be differentiated according to niche properties. Eg. A nerve cell vs. a skin cell. 4. Most animals are diploid and engage in sexual reproduction. The Animal Cell The animal cell is not confined to a rigid shape due to the absence of a cell wall. The composition of specialized cells contributes to the formation of tissues, organs and systems! The Animal cell vs. the Plant cell Properties of Animals – The three main characteristics Sensory: Animals are able to detect environmental stimuli (light, sound, touch) and interpret and process these stimuli via their Central Nervous System (CNS). Locomotion: All animals move in ATLEAST ONE stage of their life cycle. Muscles and nerves work together to allow movement. Digestion: All animals must be able to digest their food using an internal digestive system. Animals that consume other animals may use special tissues and organ to digest them. Other organisms absorb nutrients directly from the environment The Animal Cell Most Animals share the following Characteristics: SENSORY ORGANS MOVEMENT (LOCOMOTION) INTERNAL DIGESTION Properties of Animals – Life Cycle and Reproduction Relatively simple. Most animals spend majority of life as diploid organisms Almost all animals reproduce sexually – diplod adults undergo meiosis to produce sperm and eggs. Asexual reproduction can also occur – Cape honey bee, Whiptail lizards Life cycle starts with formation of zygote that forms embryo. Properties of Animals – Life Cycle and Reproduction Other characteristics of Animals Bodies can be covered in fur, scales, skin, feathers Shape of body is different according to species to accommodate the main characteristics: Locomotion, Digestion and Sensory function Main modes of locomotion include swimming, flying, walking, crawling or running. Some animals have evolved to have more than 1 form of locomotion! Some animals have the habit of migrating between habitats for reasons outside of reproduction : better habitat, food availability, unfavourable weather, comfort etc. Classifications of Animals Formal Classification: Can be based on their main mode of DOMAIN nutrition: KINGDOM CARNIVORES PHYLUM HERBIVORES CLASS OMNIVORES ORDER INSECTIVORES FAMILY Can be based on their physical GENUS characteristics: MAMMALS REPTILES FISH INSECTS Diversity of Animals What makes animals diverse?  Diversity of Animals: Form and function To stay alive and reproduce, all animals must find food, water and oxygen. Additionally, they must get rid of waste products of metabolism. How an animal organ systems operates can be considered a diversifying trait in how we classify animals. The more basic the functional system, the more basic the classification of the animal. An Earthworm vs. a Dung beetle vs. a Green lizard vs. a dog vs. an Elephant Diversity of Animals: Form and function Two animal phyla: Chordata (vertebrates only) and Anthropoda, are separated based on their skeletal makeup. Chordates boast an internal skeleton whilst arthropods have external skeletons. Diversity of Animals Other factors that contribute to the diversity of animals include: Habitat and geographic location Temperature and humidity Seasonal variation …We will cover these in upcoming lectures.