Answer:
The greenhouse and enhanced greenhouse effects refer to the return of approximately <u>80</u> percent and greater than <u>80</u> percent of the heat radiated by Earth.
Explanation:
During natural greenhouse effect : 
. Solar radiation reaches the earth 
. Re-radiation of heat occurs
. Less re-emitted heat
. More heath escapes into space 
Hence the greenhouse effect refers to return of 80% of heat radiated by Earth.
While during Human Enhanced Greenhouse effect : 
. Solar radiation reaches earth
. Re-radiation of heat occurs
. More re-emitted heat
. Less heat escapes into space
Hence the enhanced greenhouse effect refers to return of more than 80% of heat radiated by Earth .
 
        
             
        
        
        
The pituitary gland secretes a hormone called antidiuretic hormone (ADH) which reabsorbs water in the kidney from the urine
        
             
        
        
        
Answer:
<em>The sun or solar energy is at the start of almost every energy
</em>
<em>
chain.</em>
Explanation:
 
        
             
        
        
        
Answer
RIBOSOMES on the ROUGH ENDOPLASMIC RETICULUM
Explanation:
This is the site of protein synthesis usually find attached to the rough endoplasmic reticulum or  freely on the cystosol,
 When they are attached to the  endoplasmic reticulum they appeared as back dots which makes the surface of ER to appear rough, hence the name ROUGH ER. Smooth ER, lacks Ribosomes, and therefore appears smooth,
Ribosomes  are made up of PROTEIN AND RNA.
They are 25nm in diameter;when viewed under high magnification, where theymade up of  two sub-units  the small and large units.
The protein synthesize by the Ribosomes are passed into the sacs  of Rough E.R  for transportation,
 
Basically, a complete Ribosomes is refereed to as 70S for prokaryotic ribosomes and 80S for Eukaryotic Ribisomes.This refers to their sedimentation Co-efficient in Svedberg units,the Eukaryotes sediment faster than the Prokaroytes
 
        
             
        
        
        
Answer:
Some species are similar in structure because they are evolved from the same ancestors while some differences are also present in them due to the changes occurs in the body because of adaptation to environmental conditions. 
Grizzly bears and sea otters have canine teeth because canine teeth are used to crushing hard food materials such as fishes and shells. 
Explanation:
Canine teeth are present in the grizzly bear and sea otters due to eating of food materials which are hard. Canine teeth used to crush the food materials.