Fish breathe by drawing water in their mouths and forcing it out of the body via a number of gill slits. The gill slits are rich in blood vessels, enabling the direct absorption of oxygen. While all fish have gills, some fish are also able to extract oxygen from the air via gulping.
Most fish have swim bladders that are permanently sealed, but other fish have swim bladders that can hold varying amounts of air. Salmon have open swim bladders, and they must gulp air at the surface to keep them full. Some fish, such as sharks, lack swim bladders entirely. This causes them to sink if they do not maintain forward motion.
Fish have fins that are adapted to their lifestyle. Some have evolved into long, barbed structures, suitable for defense. Other fish have fins suited for achieving great speed or for walking along the bottom of the ocean.
Modelling refers to using a diagrammatic representation to present a particular event or biological activity.
The two maps shown are very good for representing/modelling mitosis.
Advantages
- They clearly lists the various steps involved in mitosis and as well included the process of cell division starting from the interphase stage (for the second diagram).
- The M phase was also clearly explained in the first diagram.
Disadvantages
- The first pictorial diagram had to labelling to depict the name of each particular phase and makes understanding difficult.
- The second diagram fails to show pictorial representation of what could have exactly happened in each stage in the process of cell division.
Learn more about cell division: brainly.com/question/796780
Answer:
The approach of cytokinesis to form cleavage furrows does not work for the plant cells due to specific reasons. These reasons are -
The presence of a rigid outermost layer called cell wall in plant cells that do not allow for forming furrows.
Centrioles present in animal cells helps in maintaining the organisation of mitotic spindle and completion of cytokinesis, however, not found in plant cells. The Golgi vesicles secrets and makes a septum or cell plate in the equatorial plane of the cell wall with the help of microtubules and phragmoplast help in the separation of two daughter cells.
