Answer:
HIV/AIDS
HIV is a disease in the blood
nothing else
it is majorly caused through unprotected sex
there are other factors tho.
But it can be transmitted in blood transfusion
it is in the blood cells
 
        
             
        
        
        
Answer:
The correct answer will be option-B.
Explanation:
The plant tissues are composed of three types of cells: parenchyma, collenchyma and sclerenchyma.
The parenchyma and collenchyma remain alive at their maturity but sclerenchyma loses their protoplasm and become dead. These cells deposit lignin in their secondary walls and form hard tissues of the plant-like hard shell of a coconut. Sclerenchyma provides mechanical strength to the plant.
Thus, Option-B is the correct answer.
 
        
             
        
        
        
Answer:
All  are true of the movement of Earth's atmosphere except :
d. Warm air is less dense than cool air so it tends to sink towards the Earth's Surface.
Explanation:
- When gases heat up, their volume increases and  density decrease. 
- A decrease in density causes a substance to become lighter.
- Thus, when air warms up due to heat from the sun its density decreases and it gets lighter.
- So, it will move up.
- The Cooler air in turn is denser and heavier so it will sink towards the Earth's surface.
- Hence, the statement d , which states that 'warm air is less dense than cool air so in tends to sink towards the Earth's Surface' is FALSE. 
 
        
             
        
        
        
Answer:
C
Explanation:
The brother has different alleles for the blood type gene than his sister does.  Blood type is inherited from parents like many other traits that can be displayed on a punnet square.  Depending on what the parents blood type alleles were, the brother and sister could have different blood types.  
A different number of chromosomes doesn't lead to different blood types, so D is wrong.  And A is incorrect because the number genes also does not affect blood type.  And I think the blood type genes are on the same chromosome, so B is wrong.  C is correct because blood type is inherited by alleles, and different alleles can cause different traits, such as blood types.