Why is O negative universal donor? People with type O- blood are called universal donors because their donated red blood cells have no A, B or Rh antigens and can therefore be safely given to people of any blood group. Plasma transfusions are matched to avoid A and B antibodies in the transfused plasma that […]

Why does my dog huff when I pet him? Huffing and Puffing: Huffing, puffing, or (in our house) “chuffing” is when the dog rapidly exhales a small amount of air, that sounds like a cross between an exhale and a bark. It’s a form of stress relief, and can also be a precursor to escalating […]

Why do sedimentary rocks have strata? Strata (singular: stratum) are the horizontal layers, or beds, present in most sedimentary rocks. During or immediately after the accumulation of sediments, physical, biological, and chemical processes produce sedimentary structures. Strata form during sediment deposition, that is, the laying down of sediment. Where are most sedimentary rocks deposited? Common […]

What happens after pollen lands on the stigma of a flower it grows a tube to travel down to the ovary it fertilizes the plant at the stigma it grows a tube to travel to the style it grows a tube to travel to the petal? The pollen tube grows longer and makes its way […]

How is deforestation related to erosion and flooding site? Deforestation causes increases in erosion and flooding. Tree root systems hold the soil together to slow the rate of flooding and reduce erosion. Trees themselves also absorb water during the rainy season. When the trees are removed from the environment, the rainy season can have devastating […]

How are invasive species harmful to humans? Invasive species can negatively impact human health by infecting humans with new diseases, serving as vectors for existing diseases, or causing wounds through bites, stings, allergens, or other toxins (Mazza et al. 2013). How do you kill invasive species? There are three main methods used for control of […]

What is the correct way to reheat potentially hazardous food? The State Sanitary Code now requires that the entire mass of all cooked and refrigerated potentially hazardous food which is to be reheated must be reheated to 165 degrees Fahrenheit or above within two hours, and held above 140 degrees Fahrenheit until served. Which of […]

How does gravity help the Earth? Gravity keeps everything on Earth from floating away! Gravity is the force that pulls objects to Earth. Without gravity, we would have no atmosphere. This means that there would be no air to breathe. What is the role of gravity in the formation of the solar system? Gravity is […]

What transports blood away from the heart? The circulatory system is made up of blood vessels that carry blood away from and towards the heart. Arteries carry blood away from the heart and veins carry blood back to the heart. The circulatory system carries oxygen, nutrients, and hormones to cells, and removes waste products, like […]

How does nonrandom mating affect allele frequencies? That is an interesting result: non-random mating, even in the most extreme form of self- fertilization, has no effect on allele frequency. Selfing causes genotype frequencies to change as the frequency of homozygotes increases and the frequency of heterozygotes decreases, but the allele frequency remains constant. How does […]