Match ends of telomere in germ cell (6)
I believe the answer is:
gamete
'germ cell' is the definition.
(I know that gamete is a type of germ cell)
'match ends of telomere' is the wordplay.
'match' becomes 'game' (I've seen this before).
'ends of' means to remove the middle letters.
'telomere' with its middle taken out is 'te'.
'game'+'te'='GAMETE'
'in' is the link.
(Other definitions for gamete that I've seen before include "Reproductive unit" , "An egg or sperm cell" , "Egg- or sperm-cell" , "Egg-cell" , "Male or female germ cell" .)