Chapter 4: The Organization of Life

Transcription

1 Chapter 4: The Organization of Life Section 1: Ecosystems: Everything Is Connected Objectives: 1. Distinguish between the biotic and abiotic factors in an ecosystem Explain how habitats are important for organisms. A. Ecosystems Do not have clear boundaries Are CONNECTED: Pollen can blow from a forest into a field, soil can wash from a mountain into a lake, and birds migrate from state to state. Examples: oak forest, coral reef B. The Components of an Ecosystem In order to survive, ecosystems need five basic components: _, mineral nutrients, _, _, and living organisms. If one part of the ecosystem is changed, the entire system will be affected. 1. Biotic and Abiotic Factors _ = alive or once-living o Examples: plants, animals, microorganisms _ = not/never alive o Examples: soil particles, sunlight, H 2 O droplets NOTE: An ecosystem includes both BIOTIC and ABIOTIC factors. 2. Organisms: individual living things Examples: human, dog 3. Species: a group of organisms that (1) ; (2) ; and (3) Examples: Homo sapiens (all humans), Canis famaliaris (all dogs) 4. Populations: groups of individuals of the same species that are living in a particular place at a particular time and that breed with one another Examples: all of the bullfrogs living in a pond, all of the bacteria living on the end of your finger 5. Communities: groups of various species that live in the same habitat and interact with each other 4-1

2 C. Habitats Habitat: the place where an organism lives o o Example: rainforest, desert, African savanna, coral reefs Because organisms tend to be very well suited to their natural habitats, they usually cannot survive for long periods of time away from them. Section 2: Evolution Objectives: 1. Explain the process of evolution by natural selection. 2. Explain the concept of adaptation. A. Evolution by Natural Selection 1. Charles Darwin Proposed that the environment exerts a strong influence over which individuals survive to produce offspring, and that some individuals, because of certain traits, are more likely to survive and reproduce than other individuals Natural selection: o Darwin thought that nature selects for certain traits, such as sharper claws, o o because organisms with these traits are more likely to survive. Over time, the population will include a greater and greater proportion of organisms with the beneficial trait. As the populations of a given species change, so does the species. o Five major points of natural selection: Table 1, p. 98 (1) (2) (3) (4) (5) 4-2

3 Evolution: 2. Nature Selects Adaptation: 3. Coevolution: the process of two species evolving in response to long-term interactions with each other B. Evolution by Artificial Selection Artificial selection: - Examples: fruits, grains, vegetables, pets C. Evolution of Resistance Resistance: the ability of an organism to tolerate a chemical designed to kill it - Examples: antibiotic-resistant bacteria, pesticide-resistant insects Section 3: The Diversity of Living Things Objectives: 1. Name the six kingdoms of organisms and identify two characteristics of each. 2. Explain the importance of bacteria and fungi in the environment. 3. Describe the importance of protists in the ocean environment. 4. Describe how angiosperms and animals depend on each other. 5. Explain the role of insects in the environment. Review: Linnaeus Classification of Living Things Largest Smallest King Phillip Came Over From Greece Smiling ***Note: The modern classification system groups the six kingdoms into three domains, and thus, the domain is a larger classification than kingdom. *** 4-3

4 The Kingdoms of Life: Table 2, p. 102 A. Bacteria 2 kingdoms: Kingdom (Domain Archaea) and Kingdom (Domain Bacteria) Most are eubacteria Characteristics of all bacteria: (1) _ (2) _ (3) Usually reproduce by binary fission (4) _ Live in every habitat on Earth Are environmentally important: (1) Break down remains and wastes of other organisms (2) _ (3) Help extract nutrients B. Fungi Kingdom (Domain Eukarya) Use chemicals to break down organic matter and absorb food through body surface Are environmentally important because they break down the remains of other organisms C. Protists Kingdom (Domain Eukarya) May be animal-like, fungus-like, or plant-like, but cannot be classified as an animal, fungus, or plant Most are microscopic and unicellular Are environmentally important: (1) (2) Bottom of food chain: phytoplankton D. Plants Kingdom (Domain Eukarya) 4-4

5 Have roots and leaves connected by vascular tissue, which transports H2O and minerals and provides support 1. Lower Plants Originally had no vascular tissue, so could not grow large Required very moist habitats in order to reproduce 1 st vascular plants: club mosses and ferns Adapted and evolved into (1) Seedless nonvascular plants (mosses and relatives) (2) Seedless vascular plants (ferns and relatives) (3) Seed plants (gymnosperms and angiosperms) 2. Gymnosperms Are woody vascular seed plants whose seeds are not enclosed by an ovary or fruit Include the cone-bearing seed plants (conifers) Are adapted for drier habitats: (1) _ (2) Produce seeds, which protect developing plants (3) Have needle-like leaves to conserve H 2 O Are environmentally important: used for lumber and paper 3. Angiosperms o Flowers (reproductive structures) pollen (male gametophyte) and/or fruit (seed storage) both of which may be transported by animals Make up the majority of modern land plants Are environmentally important: used as food, textiles, and building materials E. Animals Kingdom (Domain Eukarya) Characteristics of all animals: (1) (2) (3) Move around during at least one phase of life cycle 2. Invertebrates Are only mobile during larval stage Include most common animal on Earth: insects, which are environmentally important: (1) Pollinate plants (2) Eat pests (3) Damage crops 4-5

6 (4) Spread disease 2. Vertebrates Have a backbone 1 st vertebrates = 1 st land vertebrates = Most modern vertebrates live on land 4-6