Biodiversity 6 Vodcast 1 Flashcards

A set of flashcards reviewing key concepts related to ecdysozoans, focusing on nematodes and arthropods, for exam preparation.

What is the synapomorphy of ecdysozoans?

They all molt their exoskeleton or cuticle.

Which groups are primarily covered under ecdysozoans?

Nematodes and arthropods.

What does the term 'ecdysis' mean?

Ecdysis is Greek for 'get out of'.

Why must nematodes live in moist environments?

Their permeable cuticle requires moisture to avoid desiccation.

What is the major component that reinforces arthropod exoskeletons?

Chitin.

What type of body structure do nematodes have?

Pseudocoelomate.

How do nematodes differ from annelids in terms of segmentation?

Nematodes are unsegmented, while annelids are segmented.

What is a well-known model organism among nematodes?

C. elegans.

What unique feature do arthropods have that aids in their movement?

Jointed appendages.

How do arthropods manage to move their jointed appendages despite having a rigid exoskeleton?

The exoskeleton is thin near the joints, allowing bending.

What are the body regions of arthropods typically divided into?

Head, thorax, and abdomen.

What is the difference between the appendages of insects and those of myriapods?

Insects typically have six walking legs while myriapods have many segments with multiple pairs of legs.

What are trilobites and why are they significant?

Extinct aquatic arthropods known for their long evolutionary history.

Which group of arthropods includes spiders and scorpions?

Chelicerates.

What is the primary characteristic of chelicerates?

They have chelicerae, which are modified mouthparts for grasping prey.

What do insects use for gas exchange?

Spiracles and a system of airsacs and tubes.

Why are insects considered the most diverse group of protostomes?

They encompass over a million species.

Which insect is commonly used as a model organism in genetic studies?

Drosophila melanogaster.

What is one way that centipedes are distinguished from millipedes?

Centipedes have one pair of legs per segment while millipedes appear to have two pairs due to segment fusion.

What is the function of the cuticle in nematodes?

It enables gas and water exchange.

What is the significance of C. elegans in scientific research?

Its cells have been completely mapped and it has contributed to major discoveries like apoptosis.

How many described species of trilobites are there?

Over 17,000 described species.

What defines myriapods?

They have two body regions: a head and a long trunk with many segments.

How do chelicerates capture their prey?

Using chelicerae to grasp the prey.

What is a common feature of arthropods in relation to their body segmentation?

Segments can be fused to form distinct body regions.

How is the exoskeleton of arthropods modified near the joints?

It is thinner to allow flexibility.

What type of digestive system do nematodes possess?

A complete digestive tract with two openings.

What is a characteristic of the nervous system in nematodes?

They have a ventral nerve cord.

Why is it important that arthropods have their appendages potentially modified?

It allows for a variety of functions such as walking, grasping, and swimming.

Where can fossil trilobites commonly be found?

Around Ithaca.

How do many chelicerates benefit from their vision?

It allows for complex behaviors such as predation and courtship.

What is the relationship between insects and crustaceans accordingly to their classification?

They are united as one group called Pancrustacea.

How many pairs of appendages do crustaceans typically have on their head?

Many pairs for manipulating food.

What adaptation do insects have for gas exchange that distinguishes them from some other arthropods?

A system of spiracles and airsacs.

What type of support do arthropods gain from their exoskeleton?

Structural support due to the rigid nature of the exoskeleton.

In what way do arthropods exhibit diversity in body forms?

Variations arise from segmentation and appendage modification.

What evolutionary period do trilobites date back to?

They first appeared in the Early Cambrian.

What is a unique adaptation centipedes have for predation?

Their first pair of walking legs is modified into venomous fangs.

What major biological function do spiracles serve in insects?

Gas exchange.

How are appendages in arthropods considered during their development?

They can be turned on or off by regulatory genes.

Which environment do nematodes thrive in due to their bodily adaptations?

Moist environments.

What aspect of C. elegans has contributed to Nobel prize-winning research?

Research on apoptosis and gene expression markers.

What type of organism are crustaceans considered in terms of habitat?

Dominant marine arthropods.

How does the segmentation of arthropods contribute to their evolutionary success?

It allows for specialization of body parts and appendages.

What type of organism is an arthropod that has jointed appendages?

They include insects, crustaceans, spiders, and others.

What type of ecological roles do nematodes play?

They can be scavengers, predators, or parasites.

What notable anatomical feature of insects helps with their adaptability?

Their three-part body plan.

What are examples of organs that insects may modify their appendages into?

Mouthparts, antennae, and wings.

What is one potential impact of studying Drosophila on human health?

Research has influenced understanding of diseases like Alzheimer’s and diabetes.

What unique feature allows arthropods to have a variety of movements despite their rigid exoskeleton?

Flexible joints due to thinner exoskeleton sections.

What is the role of the chitin in arthropods?

It provides structural support and rigidity to the exoskeleton.

Why are nematodes important in ecological studies?

They play significant roles in nutrient cycling as predators and parasites.