practical lab 3 Flashcards
endoderm
inner most layer, lines the primitive gut, and gives rise to the lining of the digestive tract and its out-pocketing such as liver and lungs and vertebraes
which layer forms most of the muscles and organs between the gut and the outer covering of the animals
mesoderm
body plan of flatworms (Platyhelminthes)
acoelomate body
No cavity between the digestive tract and the other body
Smiplest body form
body plan of round worms
pseudocoelomate body plan
it has a fluid filled cavity called as the pseudocoelom. located between the digestive tract and the outer body.
layer of mesoderm under the outer body wall.
tube within a tube body plan
body organizational level seen in the annelids
coelomate body plan
have a body cavity known as the coelom , that is completely lined by the mesoderm
round worms
Phylum nematoda
example - ascaris
Differtiating feature in males for ascaris
At the posterior end males have COPULATORY SPICULE i.e. hook
How are eggs produced in ascaris
meiosis within the ovaries
what is the function of copulatory spicule
Holding the female’s genital pore open
Function of cloaca in ascaris
- found at the prosterior end of the intestine and is connected to the anus
- collecting area for fecal matter from the intestine and sperms from the seminal vesicle
Type of sperm in ascaris
amoeboid and not flagellated
Segmented worms
Phylum annelida
earthworms and clam worms
metamerism
body segmentation on the phylum annelida
clitellum? and its function
saddle like swelling on the dorsal surface of the earth worm
- produces a mucus sheath for mating
- cocoon formation within which the fertilized eggs are deposited
circulatory system in earthworms/phylum annelida
closed circulatory system
Eating pattern in earthworms
They are foraging herbivorous annelidas
Steps for food ingestion in earthworms
pharynx -> esophagus -> stored in the crop -> gizzard -> large intestine for digestion and absorption
What is the function of typhlosole (in earthworms)
increases the surface area for absorption
Excretory organs in earthworms
Nephridia
how is internal transportation done in phylum annelids
It is performed by coelomic fluid
How does reproduction occur in earthworms
mating by attachment of CLITELLA
seminal receptacles
bulb like organ which receives sperm from another worm and the sperm received is stored here.
What are parapodia? (usually in clam worms)
They are fleshy paddle like appendages that may be used for either crawling or swimming
They have a large surface area for gaseous exchange as they are rich with blood vessels
Reproductive organs in clam worms
Nereis
Feeding habits of the clam worm
carnivorous in nature
phylum arthropoda
crayfishes and grasshoppers
What are the reasons for the tremendous biological success of the phylum arthropoda?
- external exo skeleton
- joined appendages
Where are crayfishes usually found
found in aquatic environments with adequate amounts of Ca salts
What protects crayfishes from predators?
chintinous exo skeleton
Differing feature in males and females (externally) in crayfishes.
both male and female have the same number of appendages
males have modified first 2 fair of appendages known as swimmeretes
what is the function of swimmertes in crayfishes?
found in males
they are elongated and can come together to form a trough like channel to transfer the sperm
Division of the body of the crayfish
the cephalothorax and the abdomen
what is the function of the digestive glads in the crayfishes?
they are located at the posterior part of the cephalothorax and these glands secrete enzymes and also store food.
ingestion/digestion of food in crayfishes
mouth -> short esophagus-> large stomach which contain the gastric mill which are used to grind food -> intestine -> ends at anus
the osmoregulatory and excretory organ in crayfishes.
green glands (they are actually pinkish in color)
respiratory system in crayfishes
gills, they are highly vasucalireized for gaseous exchange.
ostia
small holes in the heart of the crayfishes from which the blood renters the heart
The division of the body of a grasshopper
- head
- thorax
- abdomen
how can you tell apart the 2 sexes of a grasshopper
the female has ovipositor - > modified terminal segments in the females to lay and position eggs
What are the terminal segments in a grasshopper
the terminal segments bear the reproductive genital
ingestion and digestion in a grasshopper
pharynx -> esophagus -> crop (where the food is stored) -> stomach -> attached to gastric caecae -> intestine -> rectum -> anus
what is the function of the gastric caecae
it is six doubled finger shaped digestive gland which produce enzymes which are secreted into the stomach which aid in digestion
what are the malphigian tubules
the perform the function of excretion and osmoregulation
they are rich with blood
wastes would enter the tube and are removed via the HINDGUT
what are the testes composed of in case of grasshoppers
they are composed of follicles
what are the ovaries composed of in the case of grasshoppers
they are composed of several tapering egg tubes
