Answer:
Extinct.
Explanation:
The IUCN red list classifies the organism as endangered , extinct, threatened and vulnerable organism. The organism are classified on the basis of their number and presence on the particular area.
Extinct species is the species that are no longer present on the earth. The extinct species has been eliminated due to the unfavorable environmental condition and due to human activities. No single organism is present of the extinct species.
Thus, the correct answer is option (3).
Messenger RNA (mRNA) molecules carry the coding sequences for protein synthesis and are called transcripts; ribosomal RNA (rRNA) molecules form the core of a cell's ribosomes (the structures in which protein synthesis takes place); and transfer RNA<span> (tRNA) molecules carry amino acids to the ribosomes during protein synthesis.</span>
Answer:
Sponges use <em><u>choanocytes</u></em> or <em><u>flagellated channels</u></em> to get nutrients from the feeding cells to other parts of their body.
Explanation:
Sponges are marine animals with a sac-shaped body. The epidermis is composed of polygonal flat cells called pinacocytes and pores protected by porocytes. Under the epidermis, there is a protein matrix called mesenchyme, which is composed of spicules and <em><u>amibocytes</u></em>. By the interior side of the sponge, there are the<em><u> choanocytes</u></em>. These are ovoid cells that can be shaping the spongocoele (internal cavity of the sponge), with an extreme attached to the mesenchyme and the other extreme projected to the spongocoele, or can be grouped in spaces called <em><u>flagellated channels</u></em>.
These animals depend on water to get oxygen and food to the inside of the sac and take excrements and reproductive cells to the outside. Sponges <em>feed on small detritus particles and suspending organisms</em> that get near the animal by water streams produced by choanocytes.
Particle size is essential. Only the small ones can get through the flagellated channels, where they get stuck to the choanocytes and are encapsulated by the cells. If the choanocytes are too small, the particle is transferred to the amibocytes for digestion. These last ones also act as food storages. Excrement products are dragged by a water stream.
<span>The cerebellum which is responsible for motor skills, experiences the most rapid growth during the first year of life. The cerebellum is also responsible for balance as well as muscle tone. The cerebellum is one of the most important parts of the brain.</span>
