Meninges are membranes that cover and protect the brain and spinal cord.
There are three layers of meninges: Dura mater (closest to the bone), Arachnoid loosely around the brain, Pia mater is closely attached to the brain and spinal cord surface.
        
             
        
        
        
Answer:
while the heart beats
Explanation:
Blood pressure of the heart is the pressure by which heart pumps blood through the arteries. Since the blood flow through the heart and arteries is pulsatile, there are two heart blood pressures: systolic and diastolic blood pressure. Normal systolic pressure is about  120 mmHg.
Diastolic blood pressure is the pressure of the blood between heartbeats (when heart is not active, relaxed). Normal diastolic blood pressure is about  80 mmHg.
 
        
             
        
        
        
The coenzyme required is pyridoxal phosphate. It is a vitamins B6 cofactor required for transamination reaction.
        
             
        
        
        
A frog's lungs don't work that well, but since it's skin is so thin, oxygen and carbon dioxide can pass trough it.
        
                    
             
        
        
        
Answer:Answer:
For 1: The correct answer is Model 1, 2, and 4.
For 2: The correct answer is Option 1.
Explanation:
For 1:
An element has 3 subatomic particles: electrons (E), neutrons (N) and protons (P).
Atomic number is defined as the number of protons or number of electrons.
Atoms having same number of protons are same. From the given models, Model 1, 2 and 4 have 2 protons with different neutrons. Hence, these models belong to same element.
For 2:
A compound is defined as a substance in which two or more types of elements combine in a fixed ratio. For Example:  is a compound made out of atoms of carbon and oxygen.
Hence, the correct answer is Option 2.