Defining Characteristics of Chordates and Related Concepts

Flashcards covering key concepts related to chordates, animal reproduction, population biology, and climate change.

What are the defining characteristics of chordates?

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

What subphyla are included in chordates?

Cephalochordata, Urochordata, and Vertebrata.

What traits show the relationship between hemichordates and echinoderms, as well as between hemichordates and chordates?

Hemichordates share a pharyngeal structure with echinoderms and display a notochord-like structure indicating a relationship to chordates.

What is the hypothesized ancestor of all vertebrates?

An ancestral organism that possessed features like a notochord and gill structures, similar to extant jawless fishes.

What is the function of a lateral line system?

It detects movements and vibrations in the water, aiding in navigation and hunting.

Why are shark scales referred to as denticulate?

Because they are covered in tiny, tooth-like structures called dermal denticles.

How can the sex of a shark or ray be determined?

By identifying the presence of claspers in males or lack of them in females.

What are the ampullae of Lorenzini and their function?

Electroreceptor organs that allow sharks to detect the electrical fields generated by other organisms.

Compare cartilaginous fishes and ray-finned fishes.

Cartilaginous fishes have a skeleton made of cartilage, while ray-finned fishes have a bony skeleton.

What characteristics does Tiktaalik have that are similar to tetrapods?

Limb-like structures and a neck; it lacks certain traits like fully developed limbs or toes.

Why is Tiktaalik considered an important fossil?

It represents a transitional form between fish and terrestrial vertebrates.

How are amphibians suited to life on land?

They have adaptations like lungs and limbs, but still depend on water for reproduction and moisture.

What are the functions of the membranes in an amniotic egg?

Chorion (gas exchange), amnion (protection), yolk sac (nutrient storage), and allantois (waste management).

What is significant about the evolution of the amniotic egg?

It allows for reproduction in a terrestrial environment without dependence on water.

What are defining characteristics of mammals?

Hair or fur, mammary glands, and three middle ear bones.

Compare the lower jaw anatomy of reptiles and mammals.

Reptiles typically have multiple bones in the lower jaw, while mammals have a single bone known as the mandible.

Explain the evolution of middle ear bones in mammals.

Middle ear bones evolved from jaw bones, improving sound transmission.

Identify two synapomorphies of turtle skeletons.

A bony shell and unique structure of the ribs.

Differentiate between saurischian and ornithischian dinosaurs.

Saurischians have a lizard-like hip structure, while ornithischians have a bird-like hip structure.

What is the evolutionary advantage of sexual reproduction?

It increases genetic variation, which can enhance adaptability.

Why can asexual reproduction be a successful strategy?

It allows for rapid population growth without the need for a mate.

Define male and female in terms of gametes.

Males produce small, mobile gametes; females produce larger, non-motile gametes.

How do male and female reproductive strategies differ?

Males often compete for access to females, while females may choose mates based on quality.

Describe the human reproductive cycle.

Males produce sperm continuously, while females experience cyclical ovulation and menstruation.

Define hermaphrodite.

An organism that has both male and female reproductive organs.

Explain the distinction between density-dependent and density-independent mortality.

Density-dependent factors affect population size based on population density, while density-independent factors influence populations regardless of density.

What defines carrying capacity (K)?

The maximum population size an environment can sustain.

Identify the major forces regulating populations.

Predation, competition, parasitism, and disease.

What are biomes?

Large ecological areas on the earth's surface, characterized by specific climates and plant/animal communities.

What are the differences between climate and weather?

Climate refers to long-term patterns, while weather refers to short-term atmospheric conditions.

Why are temperatures colder at the poles?

Due to the angle of sunlight, which spreads energy over a larger area.

What causes seasons?

The tilt of the Earth's axis during its orbit around the Sun.

What factors can lead to long-term climate variation?

Events like volcanic eruptions, orbital changes, and ice ages.

Describe the water cycle using terms like evaporation, condensation, and precipitation.

Water evaporates from surfaces, condenses in the atmosphere, and returns as precipitation.

How does the 'lake effect' influence climate?

It causes increased snowfall on the leeward shores of large lakes due to warm, moist air rising and cooling.

What energy source drives wind and ocean currents?

Solar energy.

Why do prevailing winds curve?

Due to the Coriolis effect caused by Earth's rotation.

What is the greenhouse effect?

The warming of Earth's surface due to trapped heat by greenhouse gases.

Which gases are considered greenhouse gases?

Carbon dioxide, methane, nitrous oxide, and water vapor.

What happens to moist air pushed up a mountain?

It cools and condenses, leading to precipitation.

Define 'rain shadow.'

A dry area on the leeward side of a mountain due to precipitation on the windward side.

How has our atmosphere changed in the last two centuries?

Significant increases in greenhouse gas concentrations, mainly due to human activities.

Compare current CO2 levels in the atmosphere to historic levels.

Current CO2 levels are significantly higher than they have been for hundreds of thousands of years.

How can pollen, tree rings, and coral rings help reconstruct climate history?

They provide proxy data about past climate conditions.

How do ice caps and glaciers form?

By the accumulation and compaction of snow over time.

What is an isotope?

Atoms of the same element with different numbers of neutrons.

How do different isotopes of oxygen affect evaporation and precipitation?

Isotope ratios can indicate temperature conditions during past climate events.

How does temperature influence evaporation and precipitation?

Higher temperatures generally increase evaporation rates and can alter precipitation patterns.

How do isotope ratios in ice provide a measure of global temperature?

The ratios reflect past temperatures when the ice formed.

What pattern of change in Earth’s atmosphere is revealed in ice cores?

Historical fluctuations in greenhouse gas concentrations correlating with temperature changes.

Why are climate scientists concerned about the data in ice cores?

It shows unprecedented rapid increases in greenhouse gases associated with climate change.

What major changes are predicted due to climate change?

Warming temperatures, sea level rise, extreme weather, and loss of biodiversity.