Answer:
Option 2: Spiracles.
Explanation:
Cartilaginous fish (also called Chrondricytes) have a skeleton of cartilage, instead of bone. There are two subclasses - Elasmobranchii and Holocephali. Sharks, rays, skates and sawfish are elasmobranchs while chimeras are holocephali.
Here’s a list of features of cartilaginous fish in comparison to bony fish:
1. Cartilage skeleton: unlike bony fish that have a skeleton made of bones (just like other terrestrial vertebrates), the skeleton of cartilaginous fish is made of cartilage.
2. Spiracles: this is a modified gill of sorts, it aids with respiration and is found slightly behind each eye. It leads directly to the mouth. Most cartilaginous fish possess this organ (exceptions are present, such as hammerhead sharks). Bony fish do not possess spiracles.
3. Ampullae of Lorenzini: absent in bony fish, these organs are electroreceptors that form a network of pores filled with a form of jelly that can transmit electrical signals. It allows the cartilaginous fish to sense electric fields in the water (such as the movements of a fish struggling), magnetic fields and temperature. Some bony fish such as sturgeon and lungfish may possess these organs, however research is still ongoing.
4. Claspers: male cartilaginous fish possess an organ known as claspers at their pelvic fin. This is used during reproduction to transfer the sperm into the female for fertilisation. As such, internal fertilisation occurs in cartilagonous fish. Bony fish do not possess this organ, and external fertilisation occurs.
There are many other characteristics that differentiate cartilaginous fish from bony fish. They're an extremely fascinating group of animals that unfortunately, is decreasing in numbers. Very little is known about many of these animals, so it is important that we do our best to conserve the sharks, rays, sawfish and chimeras before we lose them forever.
This is the smallest to largest in the organization of organisms: atom- molecule-cell-tissue-organ-organ system-organism. Tissue is just below organs.
Answer:
The correct answer is "Redwood tree; human being; Paramecium; White Blood Cell; Escherichia coli; Chickenpox virus; Ribosome; Prion fibril; Water molecule; Sulfur atom".
Explanation:
Redwood trees are gigantic trees, and its size can reach up to 90 meters.
The average size of a human being is 1.7 meters for males and 1.6 meters for females.
Paramecium are members of the protozoa genus, among the largest unicellular algae. Its average size is among 50 to 330 micrometers.
White Blood Cell are up to 17 micrometers in diameter.
Escherichia coli is a type of bacteria, as a prokaryotic organism is much more smaller than a eukaryotic cell such asa the white blood cell. Escherichia coli is up to 2 micrometers in diameter.
Chickenpox virus are among the largest viruses, they are from 150 to 200 nanometers in diameter.
Ribosomes vary on size depending if they are Prokaryotic or Eukaryotic, where the first are up to 20 nanometers and the second are up to 30 nanometers.
Prion fibrils are aggregates comprised of several protein units. It size varies depending on the number of proteins, but the ones containing around 200 units can reach up to 27 nanometers.
Water molecule is comprised of two atoms of oxygen and one atom of hydrogen, its size is measured with picometers (1 picometer is equal to 1000 nanometers). A water molecule has a size of 275 picometers.
Sulfur atom is the smallest in the list. Its size is around 100 picometers.
The answer is granzymes. are serine proteases which trigger the apoptotic cascade in target cells. Apoptotic enzymes activated by granzymes can also destroy viruses or other cytoplasmic pathogens in the target cells so that the pathogens cannot infect nearby cells. Dead target cells are rapidly ingested by macrophages. The Tc cells also produce perforin pores to allow granzymes to enter the target cell.
