Answer:
C. The reactions take up too much space in the cell if the enzymes are missing.
Explanation:
 
        
             
        
        
        
Answer:
Delivered small RNAs can inhibit protein A production through the RNA interference (RNAi) mechanism, and thus impairs angiogenesis  
Explanation:
The pregnancy-associated plasma protein-A is a protease enzyme involved in the formation of new blood vessels by increasing insulin-like growth factor I (IGF-I) bioavailability. Moreover, small RNAs (<200 nucleotides in length, generally 18 to 30 nucleotides) are non-coding RNA molecules that function in RNA silencing through the RNA interference (RNAi) pathway. Small RNAs are widely used in molecular biology laboratories because they can be delivered into specific cells in order to silence target mRNAs such as, in this case, the mRNA encoding protein A, by complementary base pairing and thereby inducing translational repression. In consequence, mRNAs complementary to delivered small RNAs are silenced through RNAi pathways, i.e., by cleavage of the target mRNA and/or mRNA destabilization.
 
        
             
        
        
        
The stage that scientists begin to ask questions and attempt to explain observations is A. forming hypotheses. This is because a hypothesis is basically a testable question about observations scientists make.
 
        
             
        
        
        
Answer:
Observers ahead of the wave observe an apparent increase in wave frequency  
Explanation:
This is the Doppler Effect. The frequency of a wave increases when the source approaches the observer and decreases as the source recedes.
B, C, and D are wrong. Observers behind the source notice a decrease in frequency.
 
        
             
        
        
        
Answer:
A Siamese cat has genes that affect it’s fur color. 
Explanation: