Lecture 17 Flashcards
Name 4 important things about animals:
- Eukaryotic cells (*no CW)
- Multicellular
- Heterotrophic
- Reproduce sexually
Are animals motile?
YES
Thanks to the nervous and muscle tissue unique to animals, what do they allow animals to do?
- respond quickly and appropriately to changes in the environment
Name all 3 types of body symmetry:
1) Asymmetry
2) Radial symmetry
3) Bilateral symmetry
What is Asymmetry?
body that cannot be divided into
symmetrical body parts (not symmetrical)
Give an example of Asymmetry:
Sponges
What is Radial symmetry?
any cut along the central body axis
results in similar halves (like cutting a pie)
Give an example of Radial symmetry:
Jellyfish
What is Bilateral Symmetry?
only one cut along one plane (2 mirror-image halves)
Give an example of Bilateral symmetry:
Lizard, cow, …
Can animal make their own food?
NO
What does this mean?
Animals are Heterotrophic
What does Heterotrophic mean?
need to ingest food
What is the purpose of digestion?
to break down edible organic nutrients
Name the 2 ways of digestion:
- Intracellular digestion
- Extracellular digestion
Which one occurs INSIDE cells
Intracellular digestion
What does Intracellular digestion consist of? (involves the creation of what?)
involves the creation of FOOD VACUOLES
How are food vacuoles made? (what process)
trough phagocytosis
How are the food vacuoles broken down?
breakdown via hydrolytic enzymes in lysosomes
Intracellular digestion is only found in WHAT?
the sponges
What is extracellular digestion then?
Breakdown of food OUTSIDE cells
Where does extracellular digestion take place?
in a compartment that is continuous with the outside of the animal’s body
What is this continuous compartment with outside of body for humans?
the digestive tract in humans
Where is there most of the absorption happening? + and via what blood vessel
Absorption of food via capillaries in
small intestine
True or False: Animals don’t need to exchange materials with their environment
FALSE, they need
What do cells need? (2)
a continuous supply of nutrients & wastes
must be eliminated
What happens if this does not happen?
it imposes limitations to their body plan
What are 2 general solutions to this problem?1
1) have a body size and shape such that most cells are in direct contact with the environment (single cell layer)
2) have a circulatory system
What are the 2 ways of circulation:
1) Diffusion
2) Circulatory system
Simple animals that lack an internal transport system rely on what?
Diffusion
What do some simple animals lack that necessitates reliance on diffusion?
An internal transport system.
What diffuses directly between individual cells and the environment? (*w/o an internal transport system)
nutrients, gases, and chemical wastes
Name three types of simple animals that rely on diffusion
Sponges, jellyfish, and some small worms (e.g., roundworms and flatworms like Planaria)
Why is diffusion effective only over small distances?
Because it is rapid only over small distances
Give an example of a unicellular organism that relies on diffusion
Unicellular organisms, such as bacteria or protozoa
How are cnidarians adapted for diffusion?
They have 2 layers of cells in constant contact with the environment.
What are the advantages of diffusion for simple animals?
Simplicity and direct exchange with the environment without complex transport systems.
Explain why sponges can rely on diffusion for their transport needs.
Sponges have a porous body structure that allows water to flow through, bringing nutrients and removing wastes directly.
NEXT (circulation)
Why did larger, more complex organisms evolve circulatory systems?
To meet the requirements of their cells that could not be met by diffusion alone
What is the primary function of the circulatory system in complex organisms?
To give almost every cell access to substances present in the external environment
How does the circulatory system benefit cells in complex organisms?
It provides access to necessary substances
What are the necessary substances, give examples:
nutrients and oxygen
How does the circulatory system integrate most other body systems?
respiratory (O2 & CO2), digestive (absorption) & urinary (transportation of waste products)
What are the 2 types of Circulatory Systems
a) OPEN Circulatory System
b_ CLOSED Circulatory System
How does an open circulatory system function in terms of bathing tissues?
It bathes the tissues directly
What is the collective term for blood and interstitial fluid in an open circulatory system?
Hemolymph
Describe the path of hemolymph in an open circulatory system:
The heart pumps hemolymph into vessels with open ends, spilling out into large spaces and diffusing back into the circulatory system.
What are the large spaces called?
sinuses
What happens to hemolymph after it spills out of the open ends of blood vessels?
It fills up large spaces called sinuses.
Name two groups of animals that have an open circulatory system.
Arthropods (including insects and arachnids) and most mollusks.
How does hemolymph return to the heart in an open circulatory system?
It diffuses back into the circulatory system, eventually reaching the heart.
What is a key characteristic that distinguishes an open circulatory system from a closed one?
blood + interstitial fluid = hemolymph.
Why might an open circulatory system be advantageous for arthropods and mollusks?
simpler and less energy loss and maintenance compared to a closed circulatory system.
Name 3 invertebrates that have a closed circulatory system
segmented worms, squid and octopuses
Name 4 vertebrates that have a closed circulatory system
birds, reptiles, amphibians, mammals
Finish the sentence: Animals lacking circulatory systems generally lack WHAT?
lack respiratory systems
Individual cells rely on what?
on diffusion directly with environment
Which part of an animal is where gases are
exchanged with the environment?
The respiratory surface
What is the movement in and out with the chemicals?
the movements of CO2 (out) and O2 (in) across the respiratory surface occur entirely by diffusion
The surface has to be 3 specific things, name them
- moist
- large
- thin
Why does the surface have to be large?
b/c it maximizes the rate of gas exchange
Why does the surface have to be moist?
so gasses can diffuse rapidly
What does the respiratory system include (for all types of animals)?
- gills
- lungs
- tracheal system (insect)
Where did life start?
in the sea
What are believed to be the closest living relatives of animals?
Choanoflagellate
Is Choanoflagellate an animal, a fungi, a protist or a plant?
A PROTIST
Name the 7 main vertebrate groups in ORDER
- Jawless fish
- cartilaginous fish
- Bony fish
- Amphibians
- Reptiles
- Birds
- Mammals
Give an example + a few characteristics of a Jawless fish:
lack jaws, fins and scales, cartilaginous skeleton (ex. lampreys)
Give an example + a few characteristics of a Cartilaginous fish:
(sharks and rays) have jaws and paired fins, mostly cartilaginous skeleton
Give an example + a few characteristics of a Bony fish:
have jaws, fins, scales, bony skeleton.(ex. lungfish, sturgeon, salmon)
Give an example + a few characteristics of an Amphibian
(frogs, toads, salamanders)
* cold-blooded, breathe through moist
scaleless skin
* often in conjunction with gills or lungs
* four limbs.
Give an example + a few characteristics of a Reptile
(crocodiles, lizards, snakes) cold-blooded, dry scaly skin, breathe with lungs
Give an example + a few characteristics of a bird:
have feathers, wings, no teeth, warm-blooded
Give an example + a few characteristics of a mammal:
have mammary glands, hair, warm-blooded.
Name 3 methods of Asexual Reproduction in Animals:
a) Regeneration
b) Budding
c) Parthenogenesis
What is Regenaration?
a piece of a parent is detached, it can grow and
develop into a completely new individual.
(like Starfish & Planaria)
What is Budding?
New individuals grow out from the parent organism (like Sponge & Hydra)
What is Parthenogenesis?
Development of an unfertilized egg into an adult individual (Daphnia or Whiptail lizards)
Animal sexual reproduction was originally adapted for which type of habitats?
for AQUATIC habitats
TRUE or FALSE: it often lack of physical contact b/w male & female
TRUE
So, how would they create zygotes (fertilized egg)?
sperm and eggs (gametes) released in large numbers and meet (external fertilization)
What is the FIRST terrestrial vertebrate?
The Amphibian
How do they breathe?
Development of lungs (adults) + gas exchange through skin
What did they develop to prevent their bodies from collapsing?
skeletal structure
How does external fertilization happen for amphibians?
female releases eggs in water, male releases sperm amid the eggs
Why do the eggs MUST remain in water?
b/c they will dehydrate
Are invertebrates successful or not on land?
Very successful on land
What do invertebrates have to reduce water loss?
a rigid exoskeleton
Is their fertilization external or internal?
INTERNAL
Do they need water to fertilize?
NO
Insects have evolved spermatophores, what are these?
packages of sperm sealed in capsules
What do they prevent the sperm from doing?
prevents the sperm from shriveling/drying up in the air.
How are invertebrates able to do gas exchanges?
Through their tracheal system
For reptiles and birds, what creates a waterproof barrier?
Scales and feathers
What do they have (organ) for gas exchange?
Efficient lungs
Internal or External fertilization?
INTERNAL fertilization
How does fertilization happen for reptiles and birds?
sperm is deposited directly within female
Do they need water for this?
NO
With the formation of WHAT are they completely independent of water?
with the formation of the Amniotic egg
What do the amniotic eggs (shelled eggs) allow?
allows for multiple births (eggs) AWAY from WATER
Name 4 important organelles within the amniotic egg
1) amnion
2) allantois
3) yolk sac
4) chorion
What collects wastes?
Allantois
What contains nutrients?
Yolk sac
Where does gas exchange happen?
in the Chorion
What is the amnion?
it protects the embryo from injury and dehydration
What is the Shell permeable and impermeable to?
impermeable to water but
permeable to O2 and CO2
What are the 2 main amniotic egg drawbacks?
- insufficient protection from predators
- cannot survive drastic environmental changes (extreme cold)
For mammals, is the fertilization internal or external?
INTERNAL fertilization
How is the development done of the young?
INTERNAL development
How do they secrete milk?
mammary glands
What are 4 characteristics about all mammals:
- mammary glands
- hair
- specialized teeth
- enlarged skull
What are the 3 groups of mammals?
1) Monotremes
2) Marsupials
3) Eutherians
What are monotremes?
Monotremes are a small group of egg-laying mammals consisting of echidnas and the platypus
Where are monotremes found?
found exclusively in Australia and New Guinea
How do monotremes reproduce?
Monotremes lay eggs, and the mothers incubate the eggs.
What is a characteristic retained from their reptilian-like ancestors?
Monotremes retain the characteristic of laying eggs inherited from their reptilian-like ancestors.
How do echidnas feed their young?
young echidna sucks milk from pores in the mother’s pouch, as they do not have nipples.
What are examples of marsupials?
opossums, kangaroos, and koalas.
Where are most marsupials found?
found in Australia and New Guinea, although not exclusively
How do marsupials differ from other mammals in terms of young development?
Marsupials have internal development of young, but the young are born prematurely.
How do marsupials rear their young?
The young marsupials are reared in pouches after birth.
How do young marsupials feed in the pouch?
Young marsupials attach to a nipple in the pouch and stay there until they can forage for themselves.
What are placental mammals also known as?
eutherians
Where does embryonic development occur in placental mammals?
occurs within a uterus
How is the embryo joined to the mother in placental mammals?
by the placenta
What does the placenta consist of?
consists of embryonic and maternal blood vessels.
What processes occur across the placenta in placental mammals? (2)
diffusion and active transport of materials between maternal and embryonic circulation.
What functions does the placenta serve for the embryo?
provides nutrients, exchanges respiratory gases, and disposes of metabolic wastes for the embryo
