[Free Registration/Login may be required to access all resource tools.] Gymnosperms have seeds, but they do not produce fruit. Instead, the seeds of gymnosperms are usually found in cones. Learn more about gymnosperms in this learning...

[Free Registration/Login may be required to access all resource tools.] When you walk outside on a cool day, does your body temperature drop? No, your body temperature stays stable at around 98.6 degrees Fahrenheit. Even when the...

[Free Registration/Login may be required to access all resource tools.] Insects have different types of appendages adapted for capturing and feeding on prey. They also have special senses that help them detect prey. Furthermore, insects...

[Free Registration/Login may be required to access all resource tools.] You can help keep your bones and skeletal system healthy by eating well and getting enough exercise. Weight-bearing exercises help keep bones strong. Learn more...

[Free Registration/Login may be required to access all resource tools.] Your skin is your largest organ and constantly protects you from infections, so keeping your skin healthy is a good idea. Learn more about keeping skin healthy in...

[Free Registration/Login may be required to access all resource tools.] Salamanders are characterized by slender bodies, short legs, and long tails. They are most closely related to the caecilians, little-known legless amphibians. Learn...

[Free Registration/Login may be required to access all resource tools.] A terrestrial biome is an area of land with a similar climate that includes similar communities of plants and animals. Different terrestrial biomes are usually...

[Free Registration/Login may be required to access all resource tools.] The mRNA, which is transcribed from the DNA in the nucleus, carries the directions for the protein-making process. mRNA tells the ribosome how to create a specific...

[Free Registration/Login may be required to access all resource tools.] Nonmetals and their properties.

[Free Registration/Login may be required to access all resource tools.] Sometimes cells need to obtain energy from sugar, but there is no oxygen present to complete cellular respiration. In this situation, cellular respiration can be...

[Free Registration/Login may be required to access all resource tools.] A person's genome is all of his or her genetic information. In other words, the human genome is all the information that makes us human. Learn more about the human...

[Free Registration/Login may be required to access all resource tools.] You are probably familiar with birds as food. Around the world, people consume chicken, turkey, and even more exotic birds, like ostriches. Can you think of other...

[Free Registration/Login may be required to access all resource tools.] How and why beta decay occurs, its dangers, beta-minus and beta-plus decay and how to write a balanced nuclear equation for beta decay.

[Free Registration/Login may be required to access all resource tools.] Boyle's law and the relationship between the volume and pressure of a gas.

[Free Registration/Login may be required to access all resource tools.] Definition of deposition and examples of deposition in nature.

[Free Registration/Login may be required to access all resource tools.] Discusses how an electric transformer works and step-up and step-down transformers.

[Free Registration/Login may be required to access all resource tools.] Explores what deafness is, how loud sounds cause hearing loss, and how to prevent hearing loss using hearing protectors.

[Free Registration/Login may be required to access all resource tools.] Ionic bonds: How and why they form, and the role of energy in their formation.

[Free Registration/Login may be required to access all resource tools.] Solubility and how temperature and pressure affect it.

[Free Registration/Login may be required to access all resource tools.] Definition and example of a surface wave, how the medium moves in a surface wave and why ocean waves break.

[Free Registration/Login may be required to access all resource tools.] What does the word "communication" make you think of? Talking on a cell phone? Texting? Writing? Those are just a few of the ways in which human beings communicate....

[Free Registration/Login may be required to access all resource tools.] The blood vessels are an important part of the cardiovascular system. They connect the heart to every cell in the body. Arteries carry blood away from the heart,...

[Free Registration/Login may be required to access all resource tools.] The sperm and egg don't look anything like a human baby. After they come together, they will develop into a human being. How does a single cell become a complex...

[Free Registration/Login may be required to access all resource tools.] The nervous system is made up of nerves. A nerve is a bundle of nerve cells. A nerve cell that carries messages is called a neuron. The messages carried by neurons...