Crossing over at prophase I results in the linked genes (those on the same chromosome) becoming unlinked and separated. Prophase I is this first stage of meiosis, the chromosomes condense, form tetrads<span>, and exchange DNA. The nucleolus and nuclear envelope disappear.</span>
        
             
        
        
        
C because who whould mesure a trend 
        
             
        
        
        
The correct answer is letter B. The microphone is the part of the telephone the converts sound waves into electrical signals that can be sent through the phone line and then towards the receiver on the other side. The telephone is one of the most important inventions made by man as it allowed communication to speed up through time.
        
             
        
        
        
Answer:D
Explanation:
Both parent are Heterozygous for the sickle cell allele. 
Both parent have sickle cell trait in which the both posses one abnormal allele of the hemoglobin beta gene (AS heterozygous genotype) 
When two AS parents mate, probability of giving birth to a sickle cell anemia child is 1/4
AS + AS= AA, AS, AS, SS