Hank introduces us to the "simplest" of the animals, complexity-wise: beginning with sponges (whose very inclusion in the list as "animals" has been called into question because they are so simple) and finishing with the most complex molluscs, octopuses and squid. We differentiate them by the number of tissue layers they have, and by the complexity of those layers.

The video resource "Simple Animals: Sponges, Jellies, & Octopuses - Crash Course Biology #22" is included in the "Biology" course from the resources series of "Crash Course". Crash Course is a educational video series from John and Hank Green.

This "Simple Stimuli Trigger Fixed Behaviors" learning object is the from the Sumanas resource series. Sumanas offers a robust selection of content and services that are directed at enhancing the learning experience.

Siyavula has produced book titles spanning Mathematics and Science subjects from Grades 4-12. These are high-quality, curriculum-aligned Open Educational Resources. This resources is a open textbooks has been developed collaboratively by a large group of contributors, including volunteers from South Africa and internationally, paid contributors and a in-house team. Each book project was managed by the Content Coordinator (a subject specialist responsible for the content, curriculum, workshop design, authoring and editing) and the Community Coordinator.

Paul Andersen describes the important features of the skeletal system. He starts by comparing and contrasting endoskeletons and exoskeletons. He then explains how the human skeleton provides support, movement, storage, blood production and homeostasis.

The video resource "The Skeletal System: Crash Course A&P #19" is included in the "Anatomy & Physiology " course from the resources series of "Crash Course". Crash Course is a educational video series from John and Hank Green.

Hank introduces us to the framework of our bodies, our skeleton, which apart from being the support and protection for all our fleshy parts, is involved in many other vital processes that help our bodies to function properly.

The video resource "The Skeletal System: It's ALIVE! - CrashCourse Biology #30" is included in the "Biology" course from the resources series of "Crash Course". Crash Course is a educational video series from John and Hank Green.

This publication from the US Dept. of Energy explores the imperative of revitalizing America's electric infrastructure. The resource, "The Smart Grid: an Introduction" included in "Lesson 1 What Is a SmartGrid" is a part of "Unit 06 Smartgrids" included in Energy & Sustainability ES - Course 4.

In this video Paul Andersen shows you how a cross between mutant and wild types of Sordaria fimicola can be used to show and measure frequency of crossing-over. He begins by reviewing the process of meiosis in a typical organism. He then shows how crossing-over can affect the formation of sports in the perithecium of the fungi.

How a sodium potassium pump can maintain a voltage gradient across a cell or neuron's membrane

The Soils Laboratory Manual, K-State Edition is designed for students in undergraduate, introductory soil science courses, and highlights the many aspects of soil science, including: soil genesis and classification, soil physical properties, soil-water interaction, soil biology, soil chemistry, and soil fertility. The lab manual includes 15 different laboratories, each one starting with an introduction and pre-lab assignment, followed by in-lab activities, and complimented by post-lab assignment. In-lab activities involve field trips, experiments, observation stations, or problem sets. Post-lab assignments include online quizzes, problem sets, or laboratory summary reports.

This image is a diagram of a proton conducting solid oxide fuel cell. The resource, "Fuel Cell Student Handout" included in "Lesson 1 Analysis of Automobiles" is a part of "Unit 03 Transportation" included in Energy & Sustainability ES - Course 4.

Paul Andersen shows you how to solve simple Hardy-Weinberg problems. He starts with a brief description of a gene pool and shows you how the formula is derived. He then shows you how to solve a couple of sample problems.

This score by Daniel Crawford is based on temperature data. The resource, "A Song of Our Warming Planet (sheet music)" included in "Lesson 3 Variation and Trend - Weather and Climate" is a part of "Unit 06 Energy Budget, Climate and Energy Resources" included in Energy & Sustainability ES - Course 2.

The resource, "A Song for our Warming Planet Redirect" included in "Lesson 3 Variation and Trend - Weather and Climate" is a part of "Unit 06 Energy Budget, Climate and Energy Resources" included in Energy & Sustainability ES - Course 2

This "Sound Transduction" learning object is the from the Sumanas resource series. Sumanas offers a robust selection of content and services that are directed at enhancing the learning experience.

Part of NCSSM CORE collection: This animation shows the hybridization of an s-orbital and three p-orbitals to form four sp3 tetrahedral hybrid orbitals

This animation shows briefly how robots are using to move plants in a large greenhouse production facility. The resource, "Spacing (Video)" within "Lesson 03 Robots" is a part of Unit 06 Precsion Ag Automation included in Agriscience & Biotechnology, Ag Bio - Course 4. The silent video is 1.5 minutes in length.

Paul Andersen explains how reproductive isolation can eventually lead to speciation. Three main barriers to gene flow are included: geographic, pre-zygotic and post-zygotic. Both allopatric and sympatric speciation are discussed. A brief discussing of polyploidy and punctuated equilibrium are also included.