How many millions of years ago were the continents last together? The word Pangaea means “All Lands”, this describes the way all the continents were joined up together. Pangea existed 240 million years ago and about 200 millions years ago it began to break apart. Over millions of years these pieces came to be the […]

What does primary productivity measure what does it tell you about an ecosystem? The level of primary productivity in an ecosystem sets the energy budget. In other words, primary productivity determines the maximum amount of energy available to all the higher trophic levels in an ecosystem. An ecosystem’s primary productivity is the rate at which […]

What might happen to a strand of RNA before it leaves the nucleus? It uses DNA as a template to make an RNA molecule. RNA then leaves the nucleus and goes to a ribosome in the cytoplasm, where translation occurs. Translation reads the genetic code in mRNA and makes a protein. Transcription uses the sequence […]

What happens in the 4 stages of mitosis? After DNA replicates and the cell is about to divide, the DNA condenses and coils into the X-shaped form of a chromosome. During this process, sister chromatids separate from each other and move to opposite poles of the cell. This happens in four phases, called prophase, metaphase, […]

How do sound waves and light waves differ from each other? Light waves are electromagnetic waves while sound waves are mechanical waves. Light waves are transverse while sound waves are longitudinal. Light waves can travel in vacuum. Sound waves require a material medium to travel, and hence, cannot travel in vacuum. How are microwaves different […]

How do the circulatory digestive and excretory systems work together? Your digestive system absorbs water and nutrients from the food you eat. Your circulatory system carries oxygen, water, and nutrients to cells throughout your body. Wastes from the cells are eliminated by your respiratory system, your excretory system, and your skin. What systems does the […]

Are Sharks Endangered 2020? Despite sharks sitting at the top of their food chain as an apex predator, they are an endangered species as a result of human activities. What sharks are almost extinct? As a result, the oceanic whitetip, porbeagle, and the smooth hammerhead are classified as vulnerable by the IUCN, while scalloped and […]

How does population size affect allele frequency? So, while allele frequencies are almost certain to change in each generation, the amount of change due to sampling error decreases as the population size increases. Perhaps the most important point is that the direction of the change is unpredictable; allele frequencies will randomly increase and decrease over […]

What is the variable called that is changed? independent variable Which variable causes the change? The idea is that one variable is the effect of another variable or, to say it another way, that one variable precedes and/or causes another. The dependent variable is the variable to be explained (the ‘effect”). The independent variable is […]

How are viruses modified for gene therapy? Certain viruses are often used as vectors because they can deliver the new gene by infecting the cell. The viruses are modified so they can’t cause disease when used in people. Some types of virus, such as retroviruses, integrate their genetic material (including the new gene) into a […]