Bio 102 - LAB > Lab 5 > Flashcards

Lab 5 Flashcards

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1
Q

Nematoda

A

the phylum = nematoda
- they are roundworms

  • there are a lot more nematodes than there are humans

***nematodes are one of the most abundant animals on earth
- are parasites in animals and plants or free-living in soil, fresh water and marine environments

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2
Q

Nematodes Benefits

A

they are beneficial
- they make soil quality better because:
- they regulate the populations of other soil organisms
- they mineralize nutrients into plant-available forms, they provide food source for other soil organisms
- they eat disease-causing organisms

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3
Q

C. Elegans

A

first multicellular organism to have its entire genome sequenced

  • they have been used as a model animal to study development and human diseases like aging and behavior
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4
Q

Metazoa clade

A

traits:
- eukaryotic cells
- multicellular
- hetrotrophic
- ingests food

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5
Q

Eumetazoa Clade 1.

A

true tissues

Cnidaria, Platyhelminthes and Nematoda

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6
Q

Eumetazoa Clade

A

animals that evolved and have bilateral symmetry (called Bilateria)

  • animals in this clade are also triploblastic

**nematoda and platyheliminthes are in this clade

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7
Q

2 Clades in Bilateria

A

the 2 major clades in Bilateria clade are: Protostomia and Deuterostomia

**platyhelminthes and nematoda are in the Protostomia clade

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8
Q

Protostomia Clade

A

within the Protostomia clade, there are 2 major clades = Spiralia and Ecydsozoa

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9
Q

Blastula

A

hallow ball of cells formed during early development

  • the fluid-filled space in the blastula = blastocoel

gastrulation: cells move inward from the surface of the blastula and form a layered embryo

***the opening that the cells move inward thru is called the blastopore

**the blastopore (first opening) becomes the mouth in the protostomes

***the second openong on deutorostomes is the mouth and the first opening is the blastore (the anus)

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10
Q

Nematode Traits

A

they are triploblastic, have bilateral symmetry and are protosomes whose blastopore becomes their mouth

**in the protosome clade and also in the Ecydosozoa clade too

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11
Q

Spiralia Clade

A

comes from a type of cleavage that occurs early in development

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12
Q

Ecdysozoa Clade

A

all animals including nematodes are in this clade

  • they have cuticle that covers the outside of their bodies
  • the cuticle is non-living so it doesn’t grow (not made of cells)
  • the cuticle has to be shed and replaced by a newer bigger one as the animal grows
  • the process of shedding the cuticle = ecdysis
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13
Q

Body Cavity

A

internal space that doesn’t open to the outside of the body

*digestive tract is not the body cavity

animals without body cavity = acoelomates

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14
Q

Mesoderm Formation

A

forms within the blastocoel but it doesn’t fill the entire cavity
- only forms inside the body wall

**the blastocoel develops into the blastocoelom in the adult roundworm

**nematodes are blastocoelomates

  • the organs are suspended in the blastocoelom and get bathed from the fluid in the blastocoelom
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15
Q

Nematodes

A

tripoblastic, have bilateral symmetry, and are in the ecdysozoa clade

  • they are protosomes, they are ecdysozoans (in protostome clade)
  • they are blastocoelomates (name for their body cavity)

**the blastocoelome is in between the body wall and gut
***no GVC

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16
Q

Body Plan: what they have

A

they have an anterior end (head)
- they have a tail end (posterior)

  • they have ventral and dorsal surfaces
  • tissues from endoderm, ectoderm, and mesoderm
  • the cuticle molts (ecdysis)
  • have fluid filled internal cavity where the mesoderm tissue lines only the body wall

**organs from the roundworm are not covered in tissue from the mesoderm

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17
Q

Nervous System Organization and Sensory Organs

A

nematodes have centralized nervous system (platyhelminthes have this too)

  • the brain of nematode is a nerve ring that surrounds the anterior end of the digestive system of the worm
  • nerve cords extend from the brain along the dorsal and ventral sides (they send info to and from the body and brain)

**nematodes have chemical receptors, taste receptors, olfactory (smell) receptors, temperature receptors, and touch receptors

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18
Q

Cuticle

A

nematodes have a cuticle that covers the outside of their bodies
- cuticle is multi-layered

  • made of collagen
  • secreted by the epidermis
    ***cuticle is not made of living cells
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19
Q

Cuticle helps with:

A

maintaining shape: tough, thick cuticle on the outside of the worm and the hydrostatic pressure in the blastocoelom gives the roundworm their round shape

protection: cuticle protects them from environment like digestive enzymes that parasitic nematodes are exposed to

movement: antagonist to longitudinal muscles

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20
Q

Support and Movement

A

The blastocoelom works as the fluid-filled internal space of a hydroskeleton

**nematodes only have longitudinal muscles that run the length of the worm

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21
Q

Getting Nutrients

A
  • roundworms eat bacteria, fungus, small animals, and dead plants and animals
  • many nematodes eat plant roots which causes a lot of damage in crops
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22
Q

Nematode Digestive System

A

they have a complete digestive system (food enter thru mouth and undigested material leaves thru a different hole, the anus)

**they have specialized digestive structures for each feeding strategy

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23
Q

Feeding Strategy

A

nematodes have a complete digestive tract so they have Regional Specialization

  • they have a mouth, muscular tube = pharynx that pumps food into the intestine
  • they have anus
  • because nematodes are blastocoelomates, they don’t have muscles around the digestive tract to move food thru
  • the pharynx force and body movement force the food thru the intenstine
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24
Q

Intestine

A

the intestine secretes digestive enzymes
- the digested nutrients move from the intensine into the blastocoelom

***the fluid-filled blastocoelom is a simple circulatory system and distributes nutrients to all parts of the worm

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25
Complete Digestive Tract and Regional Specialization
the food moves down the tube rather than sitting in the GVC (they don't have a GVC) - diff parts of the tube have specialized functions: - they have diff enzymes, muscles evolved for specific purposes, and the sturctures are good for increased absorption regional specialization is good because: - specialized digestive tract allows for more effecient digestion and absorption of nurtients - this allows animals to be bigger and more complex
26
Gas Exchange and Circulation
because nematodes are small, roundworms have high surface area to volume ratio - they have a cuticle that allows gas and water to pass thru **they still do gas exchange by diffusion across the body surface and enter the blastocoelom - the blastocoelom is a simple circulatory system that distrubutes gasses and nutrients to all parts of the worm
27
Excretion of Waste
the nitrogenous waste turns into ammonia - the ammonia is excreted by diffusion across body wall
28
Reproduction
nematodes are mostly sexually reproducing *they have separate sexes (female and male nematodes) - fertilization happens internally with the male placing the sperm inside the female reproductive tract
29
Nested Box Classification So Far...
Metazoa: all animals - Porifera Eumetazoa: all animals with tissues - Cnidaria Bilateria: triploblasty and bilateral symmetry - within bilateria is Protostomia and Dueterostomia Dueterostomia: later in sem. (just know it's part of bilateria clade) Protostomia: majority of animals - 2 groups: Spiralia and Ecydysoza Spiralia: protostomes with spiral cleavage - Platyhelminthes Ecydsozoa: protostomes with ecdysis - Nematoda
30
Process of Blastocoel
Blastula: The fluid filled space in blastula is the blastocoel Gastrulation: a blastapore forms (opening where the cells migrate during gastrulation - looks like a circle with a curved in center Protostome: ***the blastopore becomes the mouth Deuterostome: ***the blastopore becomes the anus
31
Ecydysozoa - Def.
Ecydysis is the process of shedding or molting of the outer, nonliving covering called a cuticle - nematoda - the cuticle is molted 4 times during larval stages ***the cuticle bends from the muscles applying pressure to the fluid in the blastocoelom (hydrostatic skeleton)
32
Spiralia - Def.
the cells divide in a spiral pattern during cleavage ***Platyhelminthes
33
Acoelomate
Platyhelminthes - no coelom - bo body cavity between the gut and body wall - the tissue comes from the mesoderm (mesenchyme) no body cavity (looks like hood of jellyfish)
34
Blastocoelomate
Nematoda - the tissue is from the mesoderm - muscles in the body wall *a tube in a tube - looks like a tire
35
Cuticle - Details
the cuticle is essential for nematodes - cuticle is layered covering of the worm - non-living - mostly made of collagen (protein) - cuticle is secreted by the epidermis - tough outer covering - serves as a barrier between the worm and the environment ***protects from desiccation (dehydration), pollution, and digestive enzymes - cuticle is rigid but can bend - permeable to O2 and CO2
36
Cuticle - Shape and Support
the cuticle helps keep the nematode shape - hydrostatic pressure in blastocoelom is very high - the cuticle maintains the body at a constant diameter by constraining the internal pressure of these fluids ***high hydrostatic pressure + cuticle = maintains the round shape of roundworms
37
Blastocoelom - What does it do
it's packed with organs - provides space for reproductive structures
38
Nematode Locomotion (movement)
nemotodes only have longitudinal muscles - arranged in 4 groups: 2 dorsal and 2 ventral - dorsal muscles get stimulation from the dorsal nerve - ventral muscles get stimulation from the ventral nerve ***the ventral and dorsal muscles contract separately and alternately (ventral contracts, then dorsal) - the cuticle doesn't shorten, only bends when msucles contract
39
Vinegar Eels
not actually eels, but small nematodes in unpasturized cider vinegar - they live in acidic water and eat bacteria that ferments in vinegar - harmless if ingested - the roundworms move very fast and are very thin - looks like sine wave
40
C. Elegans
free living soil nematode that lives in a lot of places and primarily eats bacteria - non-hazardous, non-infectious, non-pathogenic, non-parasitic - useful for biological study bc we share a lot of genes with them - used to do research on diabetes, alzheimers, kidney disease, aging, and tumors
41
Nematode Movement under miscroscope
they have alternating waves of contractions of ventral and dorsal muscles travel from the anterior and posterior making movement to go forward - when the muscles relax, the cuticle acts as an antagonist to return the muscles to the original shape - the waves of contractions and relaxations make the undulating movement (wave-like motion) *looks like a sine wave
42
Complete Digestive Tract
advantages of complete digestive tract: - continuous feeding is possible, so they can have continuous energy regional specialization: one way flow thru the digestive tract makes complete digestive tract possible - different sections of the digestive tract are specialized for certain functions which makes processing food more effecient - they get the most energy and nutrient from food specialized regions: mouth, pharynx, intestine, anus
43
Nematodes Getting Food
nematodes eat a lot of food - they have adaptive feeding structures - some of hooks and some have teeth *think of the slide with a bunch of diff. kinds of nematodes that eat differently
44
Getting food: Pharynx
it's a muscular pumps that is needed to overcome high pressure blastocoelomic fluid so that food can move thru the digestive tract structure: 20 muscles together - they contract rhythmically - ingest food, concentrates the food by getting rid of liquid, pulverizes it (reduces it to small particles) and then pumps it into the intestine *valve located between the pharynx and intestine
45
Movement of Food Thru Intestine
move food thru the digestive tract using waves of muscle contractions along the tract = peristalsis - contractions of muscles behind the food push it along the tract, then the next wave of muscle contractions pushes it further along the digestive tract - continues until it reaches the anus ***the movement of food thru digestive tract requires the whole body to move because there's no muscle in the wall of digestive tract ***muscles derived from mesoderm
46
Chemical Digestion and Absorption: Intestine and Blastocoelom
- intestine is simple straight tube (one cell layer thick) - intestine secretes digestive enzymes for chemical digestion absorption of digested nutrients: movement of digested nutrients across wall of intestine into the body, into the blastocoelom - food moves along by pressures from whole body movement
47
Distribution of Digested Nutrients
the nutrients get circulated thru the blastocoelom *serves as circulatory system
48
Elimination of Indigestible Material
the indigestible material exits thru the anus
49
Regional Specialization helps Digestion
*complete digestive tract is possible bc of regional specialization different anatomical and physiological adaptations for diff. functions along the digestive tract - adaptation of the inner wall of the intestine increases the effeciency of absorption from the intestine into the blastocoelom: more surface area ***microvilli on inner wall of the intestine (increases surface area)
50
Gas Exchange
no specialized gas exchange structures - O2 diffuses across the body wall into fluid in blastocoelom - then the O2 gets distributed to all cells - CO2 diffuses out from the cells to blastocoelomic fluid then across the body wall
51
Reproduction
sexes are separate (males and females) females: they have 2 ovaries - the ovaries lead to oviducts, uteri, single vagina to outside males: they have testis - sperm ducts, seminal vesicle, usually there are one or more copulatory spicules that keep the female genital pore open during copulation - keeping the female genital pore open helps the sperm get into the female reproductive tract
52
Fertilization
fertilization is internal - the eggs are fertilized - shelled eggs made and deposited into the environment
53
Excretion of Nitrogenous Waste
protein --> amino acids --> ammonia (diffuses across body) - ammonia is toxic so can't have too much of it in the body to avoid cell damage - animals in the water have water around them so they can immediately dilute the ammonia and get rid of it before they have too much ammonia inside them - ammonia is highly soluable in water so it can easily dissolve and diffuse across the cell membranes
54
functions of the cuticle list
shape and support - movement (hydrostatic skeleton): antagonist to longitudinal muscles - by shedding the cuticle, it can grow - cuticle is permeable to O2 and CO2 - barrier to environment: prevents desiccation, protection from host digestive enzymes and environmental dangers
55
functions of the blastocoelom list
shape and support - space for organs - circulation of digested nutrients, O2, and CO2 - movement -- part of the hydrostatic skeleton
56
Nematode Parasite: Ascaris
the largest nematode parasite in the human intestine - soil transmitted parasite - live in warm and moist places - adult worms live in the small intestine and mate with each other - the female produces eggs and they get released through the host's feces - the developing embryos get swallowed and the larvae hatch - then the larvae invade the wall of the intestine and get put in the lungs - larvae mature in the lungs and then move to the throat and get swallowed *when they reach the small intestine, they develop into adult worms and the cycle starts again
57
Female Roundworm Reproductive Anatomy
the female has 2 ovaries and they are the smallest diameter tube - the eggs are produced in the ovaries (tubes) - the eggs get passed to larger tubes = oviducts and get stored there - 1 oviduct for each ovary - the eggs from each oviduct move into a separate uterus - the sperm and egg unite in the uteri - then a shell forms around the fertilized egg and development starts *2 uteri come together to make a single vagin a - the vagina is a short tube *the mouth at the top of the worm and the vagina below it *embryos leave the female's body through the vagina
58
Mouth Placing
the mouth is at the anterior tip of the worm - the anterior has 3 lips (1 dorsal, 2 ventral) - there are receptors for touch, chemosensory pressure, and vibration on the lips
59
Male Ascaris Anatomy
the digestive system is the same as the female (mouth, pharynx, intestine, and anus) ***only one of each of the male reproductive structures instead of 2 like in the female - the testis are the smallest structure - sperm produced in the testes - the sperm is stored in the seminal vesicle - the spicule places the sperm into the female vagina
60
Guniea Worm
preventable disese that affects poor people in Africa - the person drinks water with a water flea that is infected with a nematode - then the water flea is digested which sets the larvae free - the nematode matures then mates - the female nematode causes blister on lower leg (when the person puts their leg in the water, the larvae get released)
61
Guinea Worm Global Eradication Program
President Jimmy Carter launched the program to eradicate the Guinea worm
62
Benefits of Nematodes
they help with the soil and environment - they release nutrients in the soil for plant growth nutrient cycling: they eat and digest organisms, and the excess nutrients get released into the soil so plants can use them
Bio 102 - LAB
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