Khan Academy
Khan Academy: Prokaryote Metabolism
Learn how prokaryotes get energy and nutrients, and find out the difference among chemotrophs, phototrophs, heterotrophs and autotrophs.
Khan Academy
Khan Academy: Prokaryote Interactions & Ecology
Learn about cooperation and "multicellularity" in prokaryotes including mutualisms, commensalisms, parasitisms. Also find out the role of prokaryotes in the carbon and nitrogen cycles.
Khan Academy
Khan Academy: Animal & Human Viruses
Learn about viruses of humans and other animals, the Baltimore classification system, and the HIV life cycle.
Khan Academy
Khan Academy: Evolution of Viruses
Learn about virus evolution and genetic variation in viruses.
Khan Academy
Khan Academy: Darwin, Evolution, & Natural Selection
Examine Charles Darwin's voyage on the HMS Beagle and his ideas about evolution and natural selection.
Khan Academy
Khan Academy: Allele Frequency & the Gene Pool
Learn how to find allele frequency and how it's different from genotype frequency.
Khan Academy
Khan Academy: Mechanisms of Evolution
When a population is in Hardy-Weinberg equilibrium, it is not evolving. Learn how violations of Hardy-Weinberg assumptions lead to evolution.
Khan Academy
Khan Academy: Natural Selection in Populations
How natural selection works at the level of genes, alleles, genotypes, & phenotypes.
Khan Academy
Khan Academy: Species & Speciation
Find out what defines a species, and learn how new species can arise from existing species.
Khan Academy
Khan Academy: Phylogenetic Trees
Learn what a phylogenetic tree is, Learn how to read phylogenetic trees and determine which species are most related.
Khan Academy
Khan Academy: Building a Phylogenetic Tree
Understand the logic behind phylogenetic trees. Learn how to build a tree using data about features that are present or absent in a group of organisms.
Khan Academy
Khan Academy: Finding Absolute Values
In this exercise, students practice finding absolute values. Students receive immediate feedback and have the opportunity to get hints and try questions repeatedly.
Khan Academy
Khan Academy: Interpreting Absolute Value
Practice understanding the meaning of absolute value in real-world scenarios. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Khan Academy
Khan Academy: Adding & Subtracting Negative Fractions
Practice adding and subtracting positive and negative fractions. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Khan Academy
Khan Academy: Subtracting Negative Numbers Intro
In this exercise, students practice subtracting negative numbers. Students receive immediate feedback and have the opportunity to get hints and try questions repeatedly.
Khan Academy
Khan Academy: Adding Decimals: Thousandths
In this exercise, students practice adding decimals in the thousandths place. Students receive immediate feedback and have the opportunity to get hints and try questions repeatedly.
Khan Academy
Khan Academy: Adding Negative Numbers
Practice adding positive and negative single-digit numbers. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Khan Academy
Khan Academy: Negative Number Addition and Subtraction: Word Problems
Practice solving word problems with negative numbers. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Khan Academy
Khan Academy: Add Within 5
Add small numbers. All answers are five or less. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Khan Academy
Khan Academy: Add and Subtract Within 100 Word Problems 1
Practice adding and subtracting to solve word problems. These questions are result unknown or change unknown problems. Numbers used are 100 or less. Students receive immediate feedback and have the opportunity to try questions...
Khan Academy
Khan Academy: Add and Subtract Within 100 Word Problems 2
Practice solving word problems with addition and subtraction. These questions are comparison problems including difference unknown, smaller value unknown, and bigger value unknown. Numbers used are 100 or less. Students receive immediate...
Khan Academy
Khan Academy: Add and Subtract Within 100 Word Problems 3
Practice solving word problems with addition and subtraction. These questions are start unknown problems including add to and take from problems. Numbers used are 100 or less. Students receive immediate feedback and have the opportunity...
Khan Academy
Khan Academy: Challenging Add and Subtract Word Problems (Within 100)
Practice solving more challenging addition and subtraction word problems with "more" and "fewer". Multi-step problems are also included. Numbers used are 100 or less. Students receive immediate feedback and have the opportunity to try...
Khan Academy
Khan Academy: Proportional Relationships
Practice telling whether or not the relationship between two quantities is proportional by reasoning about equivalent ratios. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or...