Yes
The present perfect tense of the verb "practice" is "have practiced" or "has practiced."
Past perfect: had practiced Present perfect: I/We/You/They have practiced He/She/It has practiced
practiced
I/we/you/they have practiced. He/she/it has practiced.
"Practiced" is past tense.
The present participle of "leave" is "leaving."
I/you/we/they practice. He/she/it practices. The present participle is practicing.
No leaving is the present participle of leave.
leaving
'Je pars' means 'I'm leaving' (present tense). 'Tu pars' means 'you're leaving' (present tense).
"Leaving" can be both a present participle and a past participle. As a present participle, it functions as part of the progressive verb forms (e.g., "I am leaving"). As a past participle, it is used in perfect verb tenses (e.g., "I have left").
Chromosomes. They are present in the nucleus.