Unit 2 Lesson 4 Levels of Cellular Organization Copyright © Houghton Mifflin Harcourt Publishing Company 1

Unit 2 Lesson 4 Levels of Cellular Organization Florida Benchmarks SC.6.L.14.1 Describe and identify patterns in the hierarchical organization of organisms from atoms to molecules and cells to tissues to organs to organ systems to organisms. LA.6.4.2.2 The student will record information (e.g., observations, notes, lists, charts, legends) related to a topic, including visual aids to organize and record information and include a list of sources used. Copyright © Houghton Mifflin Harcourt Publishing Company 2

Body Building How are living things organized? Unit 2 Lesson 4 Levels of Cellular Organization Body Building How are living things organized? An organism is a living thing that can carry out life processes by itself. Unicellular organisms are single-celled and do not have levels of organization. Copyright © Houghton Mifflin Harcourt Publishing Company 3

Body Building How are living things organized? Unit 2 Lesson 4 Levels of Cellular Organization Body Building How are living things organized? Unicellular organisms need fewer resources and can live in harsh conditions. They are very small and are easily eaten by other organisms. If the single cell dies, the entire organism dies. Copyright © Houghton Mifflin Harcourt Publishing Company 4

How are living things organized? Unit 2 Lesson 4 Levels of Cellular Organization How are living things organized? Multicellular organisms have multiple cells that are grouped into different levels of organization. Multicellular organisms are larger, more efficient, and have a longer life span than unicellular organisms. Multicellular organisms need more resources than unicellular organisms. The cells must depend on each other for the survival of the organism. Copyright © Houghton Mifflin Harcourt Publishing Company 5

How are living things organized? Unit 2 Lesson 4 Levels of Cellular Organization How are living things organized? A tissue is a group of similar cells that perform a common function. Humans and other animals are made up of nervous, epithelial, connective, and muscle tissues. Plants have transport, protective, and ground tissues. Copyright © Houghton Mifflin Harcourt Publishing Company 6

How are living things organized? Unit 2 Lesson 4 Levels of Cellular Organization How are living things organized? An organ is a structure made up of a collection of tissues that carry out specialized functions. Different tissues can work together to accomplish a function, such as digesting food. Plants have organs such as leaves, stems, and roots. Copyright © Houghton Mifflin Harcourt Publishing Company 7

How are living things organized? Unit 2 Lesson 4 Levels of Cellular Organization How are living things organized? An organ system is a group of organs that work together to perform body functions. Each organ system in the body has a specific job to do for the organism. Copyright © Houghton Mifflin Harcourt Publishing Company 8

How are living things organized? Unit 2 Lesson 4 Levels of Cellular Organization How are living things organized? What are the levels of organization in this tree? Copyright © Houghton Mifflin Harcourt Publishing Company 9

What’s Your Function? How do the levels of organization work together? Unit 2 Lesson 4 Levels of Cellular Organization What’s Your Function? How do the levels of organization work together? Cells, tissues, organs, and organ systems make up the structure of multicellular organisms. Structure is the arrangement of parts in an organism or object. Function is the activity of each part in an organism. Copyright © Houghton Mifflin Harcourt Publishing Company 10

How do the levels of organization work together? Unit 2 Lesson 4 Levels of Cellular Organization How do the levels of organization work together? Tiny air sacs in the lung are called alveoli. What is the structure and function of alveoli? Copyright © Houghton Mifflin Harcourt Publishing Company 11

Unit 2 Lesson 4 Levels of Cellular Organization Odd Bodies Different organisms develop many different kinds of body structures. The spiny katydid has spines to protect it from being eaten. Copyright © Houghton Mifflin Harcourt Publishing Company 12

Unit 2 Lesson 4 Levels of Cellular Organization Odd Bodies The longhorn cowfish has a puckered mouth to blow away sand on the shallow ocean floor to find and feed on tiny organisms. The tarsier has huge eyes to give it better night vision for finding insects to eat. It also has long fingers to help it grasp branches. Copyright © Houghton Mifflin Harcourt Publishing Company 13