Answer:
Prokaryotes lack a true nucleus with well defined nuclear membrane and other membrane-bound organelles. Mitochondria are the double membrane bound organelle and hence is absent in prokaryotes. Mesosome is an extension of the cell membrane presence in the cytoplasm as infolding and serves to increases surface area and as a site for cellular respiration in prokaryotes. Histones are positively charged proteins that serve in the packaging of negatively charged eukaryotic DNA but are absent in prokaryotes.
So, the correct answer is option A.(DNA is complexed with histones).
 
        
             
        
        
        
Answer:
Fish are gill-bearing aquatic craniate animals that lack limbs with digits. They form a sister group to the tunicates, together forming the olfactores. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups.
Explanation:
 
        
             
        
        
        
Answer:
Mammals
Explanation:
Humans are classified as mammals because humans have the same distinctive features (listed above) found in all members of this large group. Humans are also classified within: the subgroup of mammals called primates; and the subgroup of primates called apes and in particular the 'Great Apes'
 
        
                    
             
        
        
        
These bones are expanded into broad, flat plates, as in the cranium (skull), the ilium (pelvis), sternum and the rib cage. The flat bones are: the occipital, parietal, frontal, nasal, lacrimal, vomer, hip bone (coxal bone), sternum, ribs, and scapulae. ... In an adult, most red blood cells are formed in flat bones.
        
             
        
        
        
Answer:
A. They were part of the control group 
Explanation:
In a scientific experiment, the CONTROL GROUP as opposed to the experimental group is the group that does not receive the experimental treatment. This acts as a standard for comparison. 
In this question, the EXPERIMENTAL VACCINE is the experimental treatment or independent variable that was added. The five animal test subjects that was injected with this vaccine are called the EXPERIMENTAL GROUP while the other five test subjects that were rather injected with a PLACEBO are called CONTROL GROUPS.