The following points highlight the top eight chronological events in the progress of biology. The chronological events are: 1. Tools and Techniques 2. Systematics 3. Cells and Tissues 4. Embryology 5. Distribution. Chronological Event # 1. Tools and Techniques: 1590—Dutch spectacles makers Janssen and Janssen are credited with building first successful microscope. 1665—Robert Hooke improvised the microscopes (Fig. 6.2) and [...]
The following points highlight the top five cases on colour blindness in humans. Case # 1. Of what type will be the children with reference to colour blindness, when a man is colour-blind and his wife is normal? Solution: The cause of the colour blindness is the presence of recessive (c) gene on the X chromosome. Because man is colour-blind [...]
Learn about the comparison between three types of nephridia. Comparison # Septal Nephridia: 1. Occur in segment 15 onward. 2. Attached to the septa. 3. Vary from 80 to 100 per segment. 4. Open internally, having nephrostome. 5. Largest in size. 6. Enteronephric. 7. Remove metabolic wastes from the blood and coelomic fluid. Comparison # Pharyngeal Nephridia: 1. Occur in [...]