Chapter 12: Smaller Ecdysozoans Flashcards
Ecdysozoans possess a ___
cuticle
What is a cuticle?
Nonliving external layer secreted by the epidermis
What happens if a cuticle is firm?
Growth is restricted
The process of molting is called ____.
Ecdysis
What phyla makeup Clade Panarthopoda?
Onychophora, Tardigrada, Arthopoda
All phyla in Clade Panarthopoda have a ____.
Hemocoel
What is a hemocoel? Function?
Fusion of the main coelomic cavity and blastocoel; acts as entrance for blood from open circulatory system
What comprises hemolymph?
Blood and lymphatic fluid
What is an example of Phylum Onychophora?
Velvet Worms
Where are velvet worms (Onychophora) found?
Rainforests, tropical and semitropical leafy habitats
True/False: All velvet worms are terrestrial
True
Do velvet worms appear during the day?
No, they are nocturnal
How do velvet worms capture prey?
Entangle and Immobilize prey in slime; prey digested by enzymes, and consume only liquid part
Describe Viviparity
Form of Reproduction: Placental attachment between mother and offspring; live birth; offspring are born as juveniles
Describe Ovovivparity
Form of Reproduction: Young develop in eggs inside of the mother; eggs hatch while in uterus and live birth
Describe Oviparity
Form of Reproduction: females lay shell-covered eggs in moist places
How well can Velvet worms see?
They are nearly blind
What is the function of the Tracheal System
Enables them to breathe air, brings in air from pores scatted all over the body
What two groups make up Tactopoda?
Tardigrades and Euarthopoda
What is Anhydrobiosis? What happens to the tardigrade?
Tardigrades deal with a lack of water, and they curl up into a ball called a tun to be all dried up.
What is Trehalose? What does it do?
glass-like protective sugar that is synthesized and replaces water in the cells of tardigrades
What is Anoxybiosis? What happens to the tardigrade?
condition of insufficient oxygen; tardigrade will swell and become rigid and turgid
What is Cryobiosis?
A condition of extremely low temperatures
What is Osmobiosis?
A condition of change in osmotic pressure
What animals are tardigrades closely related to?
They are not closely related to anything else on Earth.
How many described species of tardigrades?
1000
How many legs to tardigrades have?
8 legs
What are the 3 major aquatic environments that tardigrades are found in?
Marine/brackish water, Freshwater, Terrestrial Habitats
Describe the diets of tardigrades.
Feed on cell contents of plants and algae; eat single-celled organisms or other micro animals.
What types of extreme environments can tardigrades survive?
Very low temperatures, high levels of radiation, exposure to chemicals, the vacuum of space
Explain the process of cryptobiosis as it applies to tardigrades.
The metabolism of the organism can lower to 0.01% of the normal amount which allows them to stay full/survive until conditions return to ideal.
Explain the process of cryptobiosis as it applies to tardigrades.
The metabolism of the organism can lower to 0.01% of the normal amount which allows them to stay full/survive until conditions return to ideal.
Describe “tun state”.
A ball form that tardigrades roll into during Anhydrobiosis to avoid drought.
Are tardigrades immortal?
They are resistant to extreme conditions while in a tun state but outside of the are delicate and can be killed easily.
Tardigrades are often referred to as extremophiles. Why is that not an accurate word to use to describe them?
They do not enjoy living in extreme conditions but are just good at surviving in them.
Explain the tardigrade’s unique eyes.
Have 2 single photoreceptive cells for eyes.
