Category: Physics

What protects the cell and is selectively permeable? A selectively permeable (sometimes called semi-permeable) membrane allows some molecules across but not others. JOB: The cell membrane controls what enters and exits the cell and thus protects the cell. How do organelles help keep the cell alive? Core organelles are found in virtually all eukaryotic cells. […]

Is it better to wear a hat in the sun? Wearing a hat outdoors is also great way to protect your hair, eyes, and skin from the sun’s ultraviolet (UV) rays. While you still need to slather your skin with sunscreen that protects against both UVA and UVB rays, a hat can help give added […]

Why is o not stable? One oxygen atom is unstable since it has only 6 electrons in the outermost shell. For an atom to be stable it needs 8 electrons. So, for the oxygen atom to be stable it requires two more electrons in the valence shell. Why does O2 exist but not S2? In […]

What are the three levels of physical activity? Exercise is categorized into three different intensity levels. These levels include low, moderate, and vigorous and are measured by the metabolic equivalent of task (aka metabolic equivalent or METs). The effects of exercise are different at each intensity level (i.e. training effect). What are the aims of […]

Which of the following is the leading cause of death in midlife? CLEVELAND – A recent vital statistics report from the U.S. Centers for Disease Control and Prevention (CDC) indicates cancer and heart disease remain the two leading causes of death for middle-aged Americans. What is the most common change in sleep patterns of adults […]

Do fires raise soil pH? The impact of fires on vegetation and wildlife is obvious. Nutrient levels and soil organic matter both increase after fire. Spanish research showed a significant increase in soil pH, carbon and nutrients immediately after a prescribed grass fire. How is soil affected by fire? The most dramatic effect of a […]

What will happen when a force is applied on a moving object against the direction of motion? If the force applied on the object is in the direction of its motion, the speed of the object increases. If the force is applied in the direction opposite to the direction of motion, then it results in […]

What are the top 5 driver distractions? Five Most Common Distractions While Driving Cognitive distraction. Cell phone use. Events outside the vehicle. Drivers may carry on conversations or even have arguments with their passengers while driving. Reaching for devices inside the vehicle. What type of distraction is adjusting the radio? Manual Distraction What is an […]

What are the limitations of capture-recapture? Mark / Recapture Techniques These techniques have a number of limitations: The animal usually needs to be captured to be marked, which may injure it, or alter its behaviour pattern. The mark used may harm the animal – for example a dot of a particular paint may turn out […]

What is homeostasis in cells? In biology, homeostasis is the state of steady internal, physical, and chemical conditions maintained by living systems. This is the condition of optimal functioning for the organism and includes many variables, such as body temperature and fluid balance, being kept within certain pre-set limits (homeostatic range). What is homeostatic imbalance […]