The Diversity of Animal and Fungus Life

Flashcards covering animal phylogeny, physiological systems, evolutionary history from Earth's formation to modern humans, and the characteristics of fungi.

When did the Earth form according to the lecture timeline?

$4.6$ BYA (billion years ago).

What are the four primary eras mentioned in the history of the world?

Precambrian, Paleozoic, Mesozoic, and Cenozoic.

During which period did the first animal fossils appear?

The Precambrian period, approximately $635$ mya.

What major event occurred approximately $542$ mya at the start of the Paleozoic era?

The Cambrian Explosion.

What are the four defining characteristics of an animal?

Multicellular, heterotrophic, eukaryotic, and lacking cell walls (utilizing collagen).

Which connective tissue is unique to most animals as a replacement for cell walls?

Collagen.

How is bilateral symmetry defined?

Opposite sides of the sagittal plane are mirror images of one another.

What is the difference between a gastrovascular cavity and an alimentary canal?

A gastrovascular cavity has a single opening for both digestion and distribution, while an alimentary canal is a tract with two separate openings (mouth and anus).

Which animal phyla utilize a hydrostatic skeleton?

Cnidarians, Flatworms, Annelids, and Roundworms.

Segmentation evolved independently in which three phyla?

Annelida, Arthropoda, and Chordata.

What is the developmental difference between Protostomes and Deuterostomes?

In Protostomes, the mouth develops first from the blastopore; in Deuterostomes, the anus develops first from the blastopore.

What are choanocytes in sponges?

Specialized cells with flagella that create water currents up through the osculum.

What are the two life stages of Cnidarians?

Medusa and Polyp.

What are cnidocytes?

Stinging cells used by Cnidarians to capture prey by ejecting a coiled thread often containing toxin.

How do flatworms (Platyhelminthes) exchange gases?

They lack gas exchange structures and rely entirely on diffusion.

What is the function of the radula in molluscs?

It is a scraping mouth part used for feeding.

What is ecdysis in the context of Arthropods and Roundworms?

The process of molting an exoskeleton to allow for growth.

What are the three main body segments of an arthropod?

Head, thorax, and abdomen.

What are the four key anatomical features of Chordates?

Dorsal hollow nerve cord, Notochord, Pharyngeal gill slits, and a Post-anal tail.

In vertebrate development, what does the notochord become?

The vertebrate column (backbone).

Which fossil organism, dated to approximately $375$ mya, exhibits traits of both fish and amphibians?

Tiktaalik.

What are the characteristics of an amniotic egg?

An egg with a hard outer casing and inner supportive membranes that allow reproduction away from water.

How do the hearts of amphibians, crocodiles, and birds differ?

Amphibians and most reptiles have a three-chambered heart, while crocodiles and birds have a four-chambered heart.

What distinguishes Monotremes, Marsupials, and Placentals?

Monotremes are egg-laying mammals; Marsupials develop young in a pouch; Placentals develop young internally within a placenta.

What are the defining physical characteristics of Primates?

Nails instead of claws, clavicle, two lower limb bones, opposable thumb, reduced snout, binocular vision, and increased cerebrum.

When and where did Homo sapiens originate?

East Africa, approximately $200,000$ years ago.

What are the two main forms of fungi?

Yeasts (single-celled) and Mycelia (multicellular, filamentous).