Answers:
Yes , restrictions should be given on who can buy explosives. In short only authorised officers should always investigator users of explosives, they should investigate safety and security matter that has to do with explosives. They should make a strict regulations and penalty for defaulters. I think advice should be given users and buyers that has access to, explosives to protect public safety, property and the environment.
 
        
                    
             
        
        
        
Answer:
G 0 is a resting phase where the cell has left the cycle and has stopped dividing. The cell cycle starts with this phase.
 
        
                    
             
        
        
        
<span> Mitosis involves Prophase, Metaphase, Anaphase, and Telophase. 
So you have 
13 + 12 + 3 + 2 = 30 cells in mitosis 
and 
90 + 30 = 120 cells in total 
Therefore your ratio of cells in mitosis to total cells is 30 / 120 = 1 / 4. That means mitosis should take up roughly 1/4 of the total cell cycle length. Since the completely cycle takes 24 hours, mitosis would then take (1/4)*24 = 6 hours</span>
        
             
        
        
        
Answer:
The Z lines and H- zone shortens during the muscle contraction.
Explanation:
Sarcomere is the area between the two Z lines. The Z- lines are present in the centre of I - band and H - zone is present in the A - band. The actin filaments which are thin filaments present in I- band and contracts, slide over the myosin filament during contraction. 
The I - band, H- zones are became shortens as they are thin than the A- band. It is anisotropic band having thick myosin filaments. They are not flexible and remain in its constant shape during the muscle contraction.
After the muscle contraction, the A- band and the H- zone comes to their original shape. In other words, the sarcomere shortens and comes back during muscle contraction, and relaxation.
 
        
             
        
        
        
Answer:
12:3:1
Explanation:
<em>The typical F2 ratio in cases of dominant epistasis is 12:3:1.</em>
<u>The epistasis is a form of gene interaction in which an allele in one locus interacts with and modifies the effects of alleles in another locus</u>. There are different types of epistasis depending on the type of alleles that are interacting. These include:
- Dominant/simple epistasis: Here, a dominant allele on one locus suppresses the expression of both alleles on another locus irrespective of whether they are dominant or recessive. Instead of the Mendelian dihybrid F2 ratio of 9:3:3:1, what is obtained is 12:3:1. Examples of this type of gene interaction are found in seed coat color in barley, skin color in mice, etc.
- Other types of epistasis include <em>recessive epistasis (9:3:4), dominant inhibitory epistasis (13:3), duplicate recessive epistasis (9:7), duplicate dominant epistasis (15:1), and polymeric gene interaction (9:6:1).</em>