Jesus was not born without sperm.
The Holy Spirit provided what was needed for fertilization, not cloning.
As far as the man's sperm passing down the sin nature goes?
The woman sinned first.
She was deceived.
She became fallen.
Sin entered the world though Adam! (1 Timothy 2:14)
Because he was not deceived.
Therefore, just as sin entered the world through one man, and death through sin,
and in this way death came to all people, because all sinned— Romans 5:12
Interesting point to be noted from the Greek.
When it says?...
"because all sinned."
The Greek reveals that all sinned in a single point in time!
For when Adam sinned? We all sinned.
For the sin nature was guaranteed to be passed down to all through sexual reproduction.
It is in our flesh that the sin nature holds its domain.
For I know that nothing good dwells in me, that is, in my flesh. Romans 7:18a
grace and peace ............