Why is the horseshoe crab an example of a living fossil?

Biology

2 answers:

inysia [2.3K]1 month ago

8 0

The horseshoe crab exemplifies a living fossil due to the presence of fossilized extinct ancestors, while the species remains extant today. The horseshoe crab has withstood the test of time, having survived mass extinction events and still exists. Further Explanation: Horseshoe crabs are deemed living fossils since they have remained unchanged for around 445 million years. They do not belong to the crab lineage and are not closely related to lobsters or crabs; rather, they have a closer affinity with spiders and arachnids. There are currently four known species of horseshoe crab, with Limulus polyphemus being found in North America along the Atlantic and Gulf coasts from Maine down to Mexico. Remarkably, their appearance has scarcely changed compared to ancient relatives after all this time. They feature a robust, tank-like body structure consisting of: A spike tail known as the telson (used for digging and is quite delicate), a major shell called the prosoma (the largest section), and a rear shell termed the opisthosoma (the horseshoe crab's abdomen, forming the midsection of the shell).

Rainbow [2.3K]1 month ago

3 0

A. Fossils of long-extinct ancestors of horseshoe crabs exist, and the species continues to thrive today. Explanation: Options C and D pertain more to the fossilization process. It is classified as a living fossil as its ancestors have been found in the fossil record while the species persists today.

Answer:

Exocrine glands are characterized by discharging their secretions into duct systems.

Explanation:

Exocrine glands:

These glands transport their secretions through a network of ducts that ultimately connect to the body's exterior. This means there is a direct continuity between the interior surfaces of the glands and their duct system with the external surfaces of the body (like the skin).

Examples of exocrine glands include gastric glands, salivary glands, and sweat glands.

3 0

2 months ago

Read 2 more answers

Many poisonous mushrooms are extremely colorful. One hypothesis is that the colors serve as a warning to prevent animals from ea

garik1379 [2080]

Answer:

Vibrant colors in many toxic mushrooms act as a warning to animals, signaling that consumption could be fatal.

Mushrooms belong to the fungal kingdom, and the majority of their structure consists of mycelium that resides underground. The portion that emerges above ground is referred to as the fruiting body, which resembles an umbrella. This umbrella-like structure is known as the cap, and it has gills on its underside. These gills are where spores are located, which disperse to facilitate the growth of new mushrooms.

Consequently, since the cap functions as the fruiting body and is responsible for containing spores, it is essential for mushrooms to deter predators to safeguard their reproductive parts.

6 0

2 months ago

Read 2 more answers

Jacob’s family traveled frequently by road. On a trip, he noticed that a large forest area appeared to have burned a few weeks a

garik1379 [2080]

Answer:

c The trees will thrive and the forest will revert to its former state.

Explanation:

The ashes from the previous trees will act as nutrients for the new plants, thus restoring the ecosystem as the old trees and ashes decompose, returning nutrients to the soil. Furthermore, the new seedlings will receive fresh air and sunlight, enhancing their germination process.

4 0

1 month ago

The fact that choanoflagellates and collar cells of sponges resemble each other supports the inference that ________. Group of a

Rainbow [2354]

Choanoflagellates and sponges are sister groups Explanation: Choanoflagellates are tiny unicellular organisms in the kingdom Protista, morphologically akin to the choanocyte cells of sponges, featuring a central flagellum encircled by a collar of microvilli. Consequently, choanoflagellates are often regarded as the closest living relatives of primitive metazoans, thus classifying them as sister groups to sponges. Recent molecular phylogenetic and genomic studies have backed this idea.

6 0

1 month ago