What are the chances of cystic fibrosis if both parents are carriers? A person has cystic fibrosis when both of the CF genes have mutations. This is because the person inherited one CF gene mutation from each parent. When a mother and father are both CF carriers, each pregnancy has a 1 in 4 (or […]

Which of the following is a branch of the aortic arch that supplies the left arm? The arch of the aorta has three branches: the brachiocephalic artery (which divides into right common carotid artery and the right subclavian artery), the left common carotid artery, and the left subclavian artery. These arteries provide blood to both […]

Are physical or chemical factors that cause mutations? The chemical or physical agents that cause mutations are called mutagens. Examples of physical mutagens are ultraviolet (UV) and gamma radiation. Radiation exerts its mutagenic effect either directly or by creating free radicals that in turn have mutagenic effects. What chemicals are mutagens? The most commonly used […]

How are microtubules and microfilaments similar? Microtubules are usually discussed with microfilaments. Although they are both proteins that help define cell structure and movement, they are very different molecules. While microfilaments are thin, microtubules are thick, strong spirals of thousands of subunits. Those subunits are made of the protein called tubulin. Is cytoskeleton and microtubules […]

What is the process of DNA methylation? DNA methylation is a biological process by which methyl groups are added to the DNA molecule. Methylation can change the activity of a DNA segment without changing the sequence. When located in a gene promoter, DNA methylation typically acts to repress gene transcription. How is methylation maintained during […]

What is an adverse effect of excessive immunosuppression? General risks of immunosuppressive drugs. Drugs which suppress the immune system are inevitably associated with increased risk of infection and malignancy. Many of these drugs also impact adversely on patients’ cardiovascular risk. Which client would be most likely to benefit from interferon treatment? Inhibition of tumor growth. […]

Is RNA single stranded? Like DNA, each RNA strand has the same basic structure, composed of nitrogenous bases covalently bound to a sugar-phosphate backbone (Figure 1). However, unlike DNA, RNA is usually a single-stranded molecule. Is RNA found outside the nucleus? There are two types of nucleic acids which are polymers found in all living […]

What statement is true about the electromagnetic spectrum? Answer Expert Verified The statement that tells a fact about the electromagnetic spectrum is the third option. Electromagnetic spectrum contains a spectrum of visible light and a wide array of non-visible forms of radiation. Is higher wavelength lower energy? The amount of energy is directly proportional to […]

How does light pollution affect plants and animals? Artificial night time light from sources such as street lamps affects the growth and flowering of plants and even the number of insects that depend on those plants for food, a study confirms. The research shows that light pollution can impact the natural environment in complex ways […]

Why do atoms of different elements form bonds? Why form chemical bonds? The basic answer is that atoms are trying to reach the most stable (lowest-energy) state that they can. Many atoms become stable when their valence shell is filled with electrons or when they satisfy the octet rule (by having eight valence electrons). What […]