Do women get turned on by looking at a penis, just as men get turned on looking at breasts?

Yes, some women can find looking at a penis sexually arousing, just as some men can find breasts arousing. But there isn't a simple "women respond to X, men respond to Y" rule.

Sexual arousal varies a lot between individuals. For example:

• Some women are strongly visually attracted to particular body parts or features.

• Some women are more affected by emotional connection, touch, context, or other forms of attraction.

• Some men aren't particularly interested in breasts visually either.

• Hormones, experiences, personal preferences, and the situation can all influence arousal.

So the best generalisation is: people can be sexually responsive to visual cues, but what they find attractive varies considerably from person to person and isn't determined simply by gender.