Answer:
Natural selection, mutation, and genetic drift are random events.
Explanation:
A mechanism of evolution in which the frequencies of alleles of a population change with generations because of sampling error is known as genetic drift. It takes place in all the populations of non-infinite size, however, its influences are strongest in small populations.
Hope this helps :)
Sponges are similar to other animals in that they are multicellular, heterotrophic, lack cell walls and produce sperm cells. Unlike other animals, they lack true tissues and organs, and have no body symmetry.
The shapes of their bodies are adapted for maximal efficiency of water
flow through the central cavity, where it deposits nutrients, and leaves
through a hole called the osculum. Many sponges have internal skeletons of spongin and/or spicules of calcium carbonate or silicon dioxide. All sponges are sessile
aquatic animals. Although there are freshwater species, the great
majority are marine (salt water) species, ranging from tidal zones to
depths exceeding 8,800 m (5.5 mi).
The layer of connective tissue, called the _perimysium_ , extends inward from the epimysium and separates the muscle tissue into small sections. these sections contain bundles of skeletal muscle fibers called _fascicles_ .
Additionally, bundles of contractile proteins called fibrils fill a muscle cell, called a fiber. Outside of each fiber, is the connective tissue endomysium. Bundles of fibers form fascicles, surrounded by perimysium. Bundles of fascicles and perimysium comprise the entire muscle organ, which is enclosed by epimysium.
<span>A cell with a large surface area or with microvilli (which increase surface area) are specialized for absorption. Many cells have different protein markers on their surface to accept certain specific hormones and allow them into the cell, like muscle cells reacting to adrenaline. Muscle cells are long and able to contract, allowing for overall muscle contraction and body movement. </span>
<span>I guess the hormone part I mentioned applies to chemicals; endocrine cells produce hormones that other cells would not. </span>
<span>For organelles, muscle cells don't have many of the organelles that other cells do because of their very specialized functions. </span>
<span>I hope this helps, it would literally take volumes of text books to answer this question completely.</span>