Answer:a. Retention of five functional digits on the tore and hindimbs
Explanation:
The presence of five digits or pentadactyly on the fingers as well as on the toes makes the primates distinct from other mammals. Also the keratin nails are present on each digit makes these organisms distinct from other mammals.
The five digits on the hindlimbs helps in grip of objects and on toes helps in climbing.
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.
Borders are still guarded zealously and fought for - via wars when required and when not required in equal measure. I see nations fighting
over water that preciously scarce resource of the future. I see that terrorists still abound - the Osama Bin Laden types still roam the Earth terrorizing countries and peoples with newer weapons and newer methods of instilling terror. I see that the United States is no longer the sole superpower of the world -- the most powerful country on Earth. I see the most powerful countries dominating the world as being China, India, Brazil and Russia in that order. I see that China and India have become the equivalent of the US and the erstwhile Soviet Union - fighting another Cold War between them and competing for resources and influence around the world.
Answer:
sporopollenin
While the exine is composed of sporopollenin, a complex and highly resistant biopolymer containing fatty acids, phenylpropanoids, phenolics and carotenoids, the intine is largely composed of pectin and cellulose.
Explanation:
