Name Unit 2: Characteristics of Living Things Lesson 18: From Cell To Organism Date Objective: Students will be able to compare organisms unique cells and cellular organization. Essential Questions: 1. What makes cells and organisms different? 2. How are cells organized in a complex multicellular organism? 3. What makes an organism truly multicellular? Vocabulary Words of the Day: Flagellum, Tissue, Organ, Organ System, Colonial, Organism Why It Matters: Diverse organisms have unique cells and cellular organization. Do Now 1. The largest amount of DNA in a plant cell is contained in: a. a nucleus b. a chromosome c. a protein molecule d. an enzyme molecule 2. The diagram to the right illustrates the movement of materials in a process that is vital for the energy of organisms. The process illustrated occurs within: a. chloroplasts b. mitochondria c. ribosomes d. vacuoles
1 DIVERSITY IN CELLS The different organelles and features of cells enable organisms to function in unique ways in different environments. 2 3 Flagella long threadlike structures that rotate to quickly move an organism through its environment. Pili short, thick outgrowths that allow prokaryotes to attach to surfaces or to other cells. Prokaryote Cells unicellular limited in size does not have a nucleus does not have membrane-bound organelles have flagella have pili varies the way they use energy, makeup of their cell walls & ability to move variety of shapes and structures shape reflects function Eukaryotic Cells have a nucleus have membrane-bound organelles plant cells (type of eukaryotic cell) plant cells have chloroplast & a cell wall some organelles are more important than others animal cells (type of eukaryotic cell) 4 Chloroplast a large central vacuole
5 ANIMAL CELLS do not have a cell wall are free-formed and round so not have a vacuole or chloroplast save lysosomes 6 BOTH have nucleus, ribosome, mitochondria, cell membrane, cytoskeleton, golgiapparatus, vacuole, cytoplasm, chromosome, endoplasmic reticulum Both are eukaryotic cells 7 PLANT CELLS have a cell wall are square and angular have a vacuole and a chloroplast do not have lysosomes
9 8 LEVELS OF ORGANIZATION Plants and animals have many highly specialized cells that are arranged into tissues, organs, and organ systems. TISSUES A tissue is a distinct group of cells that have similar structures and functions. For example: muscle tissue is a group of many cells that have bundles of cytoskeletal structures. When the bundles contract at the same time they help animals move. In plants, vascular tissue is made of hollowed cells that are stacked up to make tiny straws. These structures help carry fluids and nutrients to various parts of the plant. ORGANS Different tissues may be arranged into an organ, which is a specialized structure that has a specific function. In animals, the heart is an organ made of muscle, nerve and other tissues. These tissues work together to pump blood. In plants, a leaf is an organ. A leaf is made of vascular tissue and other types of plant tissues that work together to trap sunlight and produce sugar. 10 11 ORGAN SYSTEM Various organs that carry out a major body function make up an organ system. One example of an organ system is the circulatory system, which is made up of the heart, the blood vessels, and blood. In plants, the shoot system consists of stems, leaves, and the vascular tissues that connects them. Lung Tissue Lungs Respiratory System
12 13 BODY TYPES A multicellular organism is composed of many individual, permanently associated cells that coordinate their activities. CELL GROUPS Some unicellular organisms can thrive independently, but others live in groups. Cells that live as a connected group but do not depend on each other for survival are considered colonial organisms. For example, the cell walls of some bacteria adhere to one another after dividing. These formations are not considered multicellular, because the cells can survive when separated. 14 MULTICELLULARITY True multicellularity occurs only in eukaryotes, such as plants, animals and fungus. The cells of a multicellular body perform highly specific functions. Others may help with movement, reproduction, or feeding. Most multicellular organisms begin as a cell. For example, a chicken develops from an egg and new cells form by cell division. These cells can grow and undergo differentiation. Differentiation is the process by which cells develop specialized forms and function. These specialized cells are arranged into tissues, organs, and organ systems, making up the entire organism.