Ch. 29: Chordates, Vertebrates, and Their Evolution

These flashcards cover key concepts in the study of chordates, vertebrates, their evolution, and their biological characteristics.

What is the phylum that includes vertebrates?

Chordata.

What structure provides skeletal support in chordates?

Notochord.

What are the four key characteristics of chordates during development?

Notochord, dorsal hollow nerve cord, pharyngeal slits, post-anal tail.

Which species is an example of a critically endangered vertebrate?

Siberian tiger.

What is the function of the dorsal hollow nerve cord?

It develops into the central nervous system (CNS) which includes the brain and spinal cord.

What are pharyngeal slits used for in aquatic species?

They allow the exit of water and help filter food.

What is the purpose of the endostyle in chordates?

It traps food particles and produces substances similar to thyroid hormones.

How do amphibians aid in nutrient transfer to embryos?

Through the extraembryonic membranes of the amniotic egg.

What is a defining characteristic of jawless fishes?

They lack true jaws.

What distinguishes gnathostomes from other chordates?

They possess true jaws.

What are the two major classes of jawless fishes?

Myxini (hagfishes) and Petromyzontida (lampreys).

What feature is characteristic of Chondrichthyes?

Cartilaginous skeleton.

How do sharks maintain buoyancy in water?

They produce squalene oil in their liver.

What type of reproduction is common in Chondrichthyes?

Ovoviviparous, viviparous, and oviparous.

What is the primary function of the lateral line in fish?

To detect movement and vibration in the water.

What adaptations do reptiles have for living on land?

They have leathery eggs and scaly skin that reduces water loss.

What class do birds belong to in terms of amniotes?

Reptilia.

What are the three main clades of mammals?

Monotremes, marsupials, and eutherians.

What is a distinctive feature of monotremes?

They lay eggs.

What adaptation allows mammals to produce concentrated urine?

The loop of Henle.

What skeletal feature is unique to mammals compared to other vertebrates?

Lower jaw consists of only one bone (dentary).

What is the role of mammary glands in mammals?

To produce milk for nourishing young.

How do birds achieve flight efficiency?

They have contour feathers that reduce drag and enhance lift.

What is the significance of the Archaeopteryx in evolutionary history?

It displays characteristics of both dinosaurs and birds.

What do the temporal fenestrae in amniotes indicate?

Evolutionary adaptations of skull structure.

What is an example of a parameter used to classify mammals?

Presence of mammary glands.

What do you call the structure that replaces the notochord in vertebrates?

Vertebral column (spine).

How do amphibians differ from other vertebrates regarding their life cycle?

They require water for reproduction and have an aquatic larval stage.

Which group of vertebrates exhibit external fertilization as a common trait?

Many frogs (Anura).

What type of ecological roles do fish occupy?

They can be predators, prey, scavengers, or filter feeders.

What defines the class Osteichthyes?

Presence of a bony skeleton and swim bladder for buoyancy.

What characteristic differentiates reptiles from amphibians?

Reptiles lay eggs that are adapted to terrestrial life (amniotic eggs).

What is the significance of feathers in birds?

They provide insulation and enable flight.

What adaptations exist in snakes?

Leglessness, a specialized skull structure, and venomous fangs in some species.

What is the evolutionary significance of Tiktaalik?

It represents a transitional form between fish and tetrapods.

What type of habitat do most amphibians require for reproduction?

Aquatic habitats or moist environments.

What kind of lifestyle do most marsupials exhibit?

They have a pouch for carrying young after birth.

How does the anatomy of birds relate to their ability to fly?

They have lightweight pneumatic bones and an efficient respiratory system.

What does the term 'ectothermic' mean regarding reptiles?

Their body temperature is regulated by external environmental conditions.

Which group of mammals are known for having both live births and eggs?

Marsupials (some can lay eggs, but primarily give live births).

What role does the cerebellum play in vertebrates?

It is involved in the coordination of movement and balance.

What distinguishes lobe-finned fishes from ray-finned fishes?

Lobe-finned fishes have fleshy, bony limbs, while ray-finned fishes have slender, bony fins.

How do reptiles utilize their skin for survival?

Their scaly skin helps reduce water loss and provides protection.

What is the role of cutaneous respiration in amphibians?

It allows respiration through the skin to supplement lung function.