Answer;
C. His mother carried at least one allele for that trait
Explanation;
-Men have a single allele of each gene on the X chromosome, inherited from their mother, and a single allele of each gene on the Y chromosome, from their father. 
-A sex-linked trait is a trait that is controlled by a gene or an allele located on the sex chromosome.
-X-linked traits are maternally inherited from carrier mothers or from an affected father. Each son born to a carrier mother has a 50% probability of inheriting the X-chromosome carrying the mutant allele.
 
        
                    
             
        
        
        
Answer:
B
Explanation:
Any drug sold in the supermarkets, convenient stores etc  without prescriptions are called OTC-medication or over the counter drugs.
They are the group of drugs commonly abused  by young adults. Recommendation by  National Institute  on Drug Abuse is that , any  use of drug not related to medical purpose, but for mind-altering effects or arousal is regarded as an abuse. No doubt  these drugs are obtained over the counter because they are very easy to get, very cheap and legalized  by law to buy, thus easily accessible.
They drugs are high in contents which produces psychoactive effects when imbibed in over dose, and some may have damaging effects on the kidney and liver.
Other effects on the body physiology includes headaches, vomiting, nausea, seizures, tremors. etc.
 
        
                    
             
        
        
        
Answer:
Brain and spinal cord
Explanation:
Meningitis is the inflammation of the protective covering of the meninges, the three membranes covering the brain and spinal cord. Meningitis usually occurs from a viral infection, but may sometimes result from a bacterial or fungal infection, cancer or drug allergies.
Viral and bacterial meningitis may be contagious and can be transmitted through coughing and sneezing.
Symptoms of meningitis include:
- sensitivity to bright light
Treatment is by vaccination, use of antibiotics and antifungal agents.
 
        
             
        
        
        
It is because leaves are the main users of photosynthesis in a plant. The sunlight seeps into the leaves, and the leaves transform the sunlight's energy into sugar; their food.
I hope this helps! :)
        
             
        
        
        
Plants and trees use photosynthesis