Answer:
The disease is caused by the ciliate protozoan Ichthyophthirius multifiliis, commonly called ich or ick. Fish infected with ich typically develop small, blister-like, raised lesions (white spots) on the skin and/or fins.
Explanation:
Answer: genotypic ratio 2/4
Phenotypic ratio 4/4 is the same
Explanation: suppose RR is the dominant female and Rr is the heterozygous male. Then after the cross genetically 2 have RR and 2 have Rr ratio. But phenotypically all 4 are the same.