Chapter 17: Annelids, Clade: Clitellata, Class: Oligochaeta Flashcards
They live in what habitats?
- fresh water or soil, very few are parasitic or marine
Nearly all of them bear what? But in fewer number than class polychaetes .
seta
They burrow in _____ and usually live in ____. Often called?
- moist rich soil
- branched interconnected tunnels
- night crawlers
What is food stored in?
- a thin walled crop
What grinds food into small pieces?
- muscular gizzard
Digestion and absorption occur where?
- intestine
What increases the surface area for absorption?
- typhlosole
What tissue surrounds the intestine and synthesizes glycogen and fat?
- Chloragogen
What two things aid in the transportation of food, wastes and respiratory gases?
- coelomic fluid and blood
What kind of system does the blood circulate in? With what five things running lengthwise in the body?
- closed circulatory system
- five main trunks
The dorsal vessel contains ___ and functions as a ____.
It pumps blood ___ into five pairs of ___.
The _____ ensure steady pressure in ventral vessel.
- valves, true heart
- anteriorly, aortic arches
- aortic arches
The ventral vessel serves as what? Delivering blood to body walls, nephridia, and digestive tract.
- aorta
The blood contains colourless _____ and dissolved ___.
- ameboid cells
- hemoglobin
There are ___ special gaseous exchange organs.
- no
Gass exchange occurs where?
across the body surface
In damp rainy weather they occupy where?
In dry weather?
- near the surface
- burrow deep underground and go dormant coiled in a slime chamber
Peristaltic movements:
Step 1. Contractions of _______in the anterior end lengthen the body, pushing the anterior end forward where it anchors.
circular muscles
Peristaltic Movements:
Step 2. Anchoring is accomplished by contraction of the _______ in forward segments.
longitudinal muscles
Peristaltic Movements:
Step 3.Anchoring Causes the segments to become ___ and ____pushing against the burrow.
- short and wide
Setae what are they? Function? GO
- bristle like rod set in a sac and moved by tiny muscles
- project outward through small pores in cuticle
- aid in anchoring by digging into walls of burrow
What is their main method of getting a food source?
- scavenging
L> feeding on decaying organic matter, leaves, refuse etc
Food is moistened by the ___ and drawn in by a sucking action of the _____.
- mouth
- muscular pharynx
Calcium in soil leads to_____.
high blood Ca 2+
What along the esophagus reduces calcium ion concentration in the blood?
- Calciferous glands
Why is too much calcium ion bad?
- blood will crystallize and cause blockages
Where are metanephridia located which aid in excretion?
there are a pair of metanephridia in each somite except the first three and terminal one
The nervous system consists of what two things?
CNS and peripheral nerves
A pair go cerebral ganglia connect around the ___ to the ganglia of the __.
- pharynx
- ventral nerve cord
Fused ganglia in each somite contain both ___ and ___.
- sensory and motor fibers
Neurosecretory cells in the brain and ganglia secrete ____.
- neurohormones wich regulate reproduction, secondary sex characteristics and regeneration
One or more ____ located in ventral nerve cord increase the rate of ___ and stimulate _____ of many muscles in many segments.
- giant axons
- conduction, contractions
General Behaviour:
- They avoid right light which is called ?
- What is important in locating food?
- They have a limited learning ability which is?
- negative phototaxis
- chemical stimuli
- trial and error learning
Reproduction and Development :
- The sexes are not separate therefore they are classified as ?
- In Lumbricus, reproductive structures are located in what somites?
- Sperm is produced by ___ and matures in the ____ and pass into ___.
- Eggs are discharged by __ into ____ and ciliated funnels transport them outside.
- Two pairs of ____ receive and store sperm.
- monoecious
- 9 through 15
- testes, seminal vesicles, sperm ducts
- ovaries, coelomic cavity
- seminal receptacles
What time of the day and what kind of weather do they mate in?
- night during warm, moist weather
Describe the Process of mating:
- Aligning on opposite directions ___ surfaces together.
- Mucus secreted by ___ holds the worms together.
- Sperm from each worm are transported to the ____ of the other along ____.
- After mutual copulation, each worm secretes a ___ and ___ to form a cocoon.
- The cocoon passes forward and __, __ and __ are added.
- Fertilization and embryogenesis occur in the __.
- ____ will emerge from the cocoon.
- ventral
- clitellum
- seminal receptacles , seminal grooves
- mucus tube, chitinous band
- sperm, eggs and albumin
- cocoon
- young worms
