Name any two fixatives that are commonly used in biology and mention a group of organisms in which each of these fixatives is applied.

1. Formalin: Formalin is commonly used as a fixative in histology to preserve tissues for microscopic examination. It is often used in the study of human and animal tissues.

2. Carnoy's solution: Carnoy's solution is a fixative commonly used in cytogenetics to preserve chromosomes for analysis. It is often used in the study of plant tissues, particularly in the field of plant genetics.

1. Formaldehyde:

- Application: Animal tissues

2. Glutaraldehyde:

- Application: Plant tissues and electron microscopy