Cell Structure and Function Chapter 1

Overview of Cells What is a cell? The basic unit of structure and function for all living things The structure of living things is determined by how the cells are put together Cells carry out all of the functions of an organism (e.g. breathing, digesting food, and growing) Cells are small – 1cm2 of skin contains 100,000 cells

First Observation of Cells Before 1600 no one knew cells were there because they could not see them What invention led to their discovery? The microscope made it possible for people discover and learn about cells

Robert Hooke (1635-1703) – English inventor and scientist built his own compound microscope – in 1663 looked at cork He saw tiny boxes that he called “cells” which means “small rooms” From his observations he calculated that 1 cubic inch contained about 1,200,000,000 cells

Anton van Leeuwenhoek – Dutch cloth salesman – built microscopes in his spare time He looked at drops of lake water, teeth and gum scrapings, rain gutter water and saw little organisms – called them animalcules – means “little animals”

Development of Cell Theory Three German scientists came up with cell theory In 1838 - Matthias Schleiden said all plants are made of cells In 1839 – Theodor Schwann concluded that all animals are made of cells (therefore all living things are made of cells) In 1855 – Rudolf Virchow stated that “all cells come from other cells”

All living things are made of one or more cells. Cell Theory All living things are made of one or more cells. Cells are the basic units of structure and function in living things. All cells are produced from other cells.

Characteristics of Life Organization Cells contain structures that have specialized functions. Human body systems. Responses Cells in your body can recognize invaders and respond with different processes.

Growth & Development Organisms grow, they increase in size. Growth in multicellular organisms- organisms made of many cells-happens as the number of cells increase. Reproduction For organisms to continue to exist they need to reproduce and create offspring. (sexual) Other organisms can reproduce without a mate. (asexual)

Homeostasis Organism trying to keep internal conditions within certain limits. Humans maintain homeostasis of body temperature by sweating, shivering, or changing the flow of blood.

Unicellular and Multicellular Unicellular organisms in domain and domain are the most numerous organisms on Earth In multicellular organisms (domain ) cells are often organized into tissues, organs, and organ systems What are some examples in plants and animals of tissues, organs and organ systems?