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.
The skeletal system since the brain is apart of the skeletal system.
Answer:
Probability is the chance that a given event will occur. The principle of probability allows us to predict the possible combinations of phenotypes in a genetic cross by using a diagram called Punnett squares. This diagram represents alleles and gives us the genetic variations formed during a cross. For example, a flower has one dominant allele for a blue color, which is represented by capital T, and one recessive allele for a pink color, which is represented by small t. When this flower is crossed with another flowering plant with the same type of alleles, which is Tt, the combinations produced for their offspring includes TT, Tt, tT, and tt.
I worked hard to write this and it would be awesome if I was marked brainliest
Direct effects, as the name suggests, while not manipulated or communicated by a third party, deal with the direct influence of one entity on another. Indirect effects can be described as the influence, mediated or passed on by a third, of one organism or species on another.
Skin cells are made of proteins, water, and fat. But brain cells are only made up of amino acids, which ca make protein.<span />
