The functions of lymphatic system are:
To provide generic defenses against any type of invaders which happen to breach our barriers, remove any debris left after the invasion has been stopped, and then fill in the damaged area with scar tissue.
The main cells of immune response are found in lymph: B and T lymphocytes are produced in lymphoid tissue (T lymphocytes mature in thymus (or tonsils)) and concentrated in the lymph nodes.
To collect excess tissue fluid and make it pathogen free before returning it to the bloodstream.
Lymphatic system drains and cleans interstitial fluid from tissue spaces and also returns leaked plasma proteins to the blood.
It also transports lipids and lipid-soluble vitamins absorbed from the digestive system.
Big lymph vessels -lacteals are at the beginning of the gastrointestinal tract and their role is to transport fats (lipids) and vitamins to the blood circulation via the thoracic duct.
Answer:
Frequency of individuals with recessive trait(dd)
%
Explanation:
Please see the attached.
In the image it is clear that there are total 
mouse out of which 
are dark colored.
Since dark color allele is dominant, these dark colored mouse will have genotype either DD or Dd
The individuals with genotype "dd" will be of light color.
Number of light colored mouse 
Frequency of individuals with recessive trait(dd)
%
