The human brain can be divided into three<span> main parts: the forebrain, midbrain, and hindbrain: 1/ The forebrain includes the several lobes of the cerebral cortex that control higher functions.</span>
        
             
        
        
        
Answer:
The correct answer is - 1/2
Explanation:
the ability to roll the tongue is dominant over those who can not roll the tongue. The man is Rr (man), heterozygous. The woman is recessive and can not roll
Rr (man) x rr (woman)---Parents
            r
R	Rr (roll)
r	rr (cann't roll)
The probability of their children to able to roll = 1/2 = 50%
 
        
             
        
        
        
Chirping, if that's what you mean.
        
             
        
        
        
Answer:
Steps in which blood travels through the heart from the time it enters from the systemic circuit until it returns to the systemic circuit are:
-  Aorta receives the oxygenated blood from the left ventricle.And gives it to systemic arteries. 
- Cells recieve the oxygenated blood and give out carbon dioxide laden blood.
- The superior and inferior venacava bring deoxygenated blood to the right atrium.
- The deoxygenated blood then moves into the right ventricle.
- Deoxygenated blood reaches lungs through Pulmonary artery.
-  Left Atrium recieves blood from lungs through pulmonary veins..
- Oxygenated then moves into Left Ventricle.
- Aorta recieves the blood from the Left ventricle
Explanation:
There are Two types of circulation in human body; the pulmonary circulation and the systemic circulation.
In Pulmonary circuit the blood is pumped into the lungs from the right ventricle to the lungs through pulmonary arteries. In this circulation the blood gets oxygenated.
In Systemic circuit the oxygenated blood from the lungs is pumped into aorta by the Left ventricle so that it can reach the body tissues,
- This circuit also brings deoxygenated blood from the body to the Right atrium of the heart.
-  Blood enters the systemic circuit when Aorta receives the oxygenated blood from the left ventricle.
- The oxygenated  blood then flows into the systemic Arteries and reaches the body tissues.
- Cell consumes the the required oxygen and nutrients then adds carbon dioxide, hormones and waste material to the blood.
- The systemic veins collect the deoxygenated blood.
- The deoxygenetated blood from upper half of the body is carried by superior vena cava and the blood from lower half of the body is carried by inferior vena cava.
- Both superior and inferior vena cava bring the blood to the right Atrium.
- From the right atrium, the  blood moves into  right ventricle through tricuspid valve.
- The Pulmonary artery carries the blood from right ventricle to the lungs.
- After the carbon dioxide diffuses out and oxygen is added, the blood is taken up by pulmonary vein.
- The Pulmonary vein brings the oxygenated blood to the left atrium of the  heart.
- The blood then moves into the left ventricle through the bicuspid valve.
- The left ventricle then  pumps the blood into the Aorta through aortic valve returning the circulating blood to the systemic circuit
 
        
             
        
        
        
Answer:
<em>The correct options are A) They move to another environment.</em>
<em>B) They risk dying out.</em>
Explanation:
According to natural selection, only those organisms are able to live and survive in an environment which can adapt to the changes in an environment. Such organisms reproduce and pass on their characteristics to their offsprings.
Organisms which are not able to adapt to changes in an environment either migrate to other places or die as they are not able to survive by the changes being made.