Results

Plant cells have a cell wall in addition to a cell membrane, whereas animal cells have only a cell membrane. Plants use cell walls to provide structure to the plant. Plant cells contain organelles called chloroplasts, while animal cells do not. Chloroplasts allow plants to make the food they need to live using photosynthesis.

This YouTube video explains how to calculate an irregular area on a map.

This YouTube video explains how to calculate a regular area on a map.

Video 1: The meaning of percent
Video 2: Meaning of 109%
Online activity 1: Percents
Video 3: Percents from fraction models 
Online activity 2: Percents from fraction models 

This online tutorial guides you through what information a map shows, map legends and the different types of maps which are available.

Food webs are models that demonstrate how matter and energy is transferred between producers, consumers, and decomposers as the three groups interact within an ecosystem. Transfers of matter into and out of the physical environment occur at every level. Decomposers recycle nutrients from dead plant or animal matter back to the soil in terrestrial environments or to the water in aquatic environments. The atoms that make up the organisms in an ecosystem are cycled repeatedly between the living and nonliving parts of the ecosystem.

Overview of animal and plant cells. Topics include cell walls, vacuoles, chloroplasts, peroxisomes, lysosomes, mitochondria, etc.

This video explores percentage changes.

This online tutorial will provide you with some guidelines on how to interpret both topographic and geologic maps.