Chapter 11 Flashcards
Animals
multicellular eukaryotes
all are heterotrophs and acquire nutrients by ingestion
Movement
a characteristic of all animals
Movement can refer to
- beating of cilia or the waving of tentacle to capture prey
- locomotion, movement from place to place
Some animals like hydra or sponges are
sessile, meaning they don’t move
The hydra (phylum Cnidaria) feeds by
moving it tentacles and stinging prey that swims near enough to touch
Some mollusks have a mantle which
secretes a shell that offers protection
Some arthropods, like crabs and grasshoppers, have an exoskeleton
consisting mostly of the polysaccharide, chitin, which does not grow with the animal and must be shed periodically
Exoskeletons
protects the soft body inside
in combination with muscles, it enables the animal to move rapidly
Animals, like the nematodes (roundworms). flatworms (planaria), and annelids (earthworms) have a
hydrostatic skeleton, a closed body compartment filled with fluid
-muscles change the shape of this fluid-filled compartment enabling the animal to move from place to place
Chordates, like frogs, cats, and humans, have an
endoskeleton made of bone and cartilage that grows as the animal grows
Bones are connected to each other at joints by
ligaments while tendons connect bones to muscles
Remember
endo vs exo skeleton
endoskeleton grows the animal
exoskeleton does not
Most life exists only within a fairly narrow range from
0 C - 50 C
What’s the most stable environment and experience the least fluctuation in environmental temperatures?
the ocean
Temperatures on land
fluctuate enormously
The size of ears in a jackrabbit can be correlated to
the climate it lives in
Jackrabbits ear’s in cold vs. warm
C: small ears close to the head to minimize heat loss
W: long ears to dissipate heat from the many capillaries that make their ears appear pink
How else can animals regulate body temperatures ?
by changes in behavior
Snakes
warm itself in the sun and cool off by hiding in the shade
Bees
swarming in a hive raises the temperature inside the hive
Dogs
pant and sweat through their tongues
Elephants
lack sweat glands but wet down their thick skin with water and flap their ears, which are rich in capillaries
Humans
shiver/jump around to keep wamr
Animals on a cold prairie in winter
huddle to decrease heat loss
Ectotherm
means heated from outside
closest in meaning to cold-blooded
Endotherm (Homeotherm)
the scientific word for warm blooded
-maintaining a constant body temperature despite changes in the environmental temperature
Which animals are endotherms/homeotherms?
birds and mammals
Being ‘warm-blooded’ requires
enormous energy
How did being warm-blooded give birds and mammals an edge in ancient Earth when the dominant animal was the reptile?
mammals and birds can be active at any time while reptiles can only be active when the temperature permits it
Excretion
removal of metabolic wastes
these include water, CO2, and nitrogenous wastes
3 different types of nitrogenous wastes
ammonia
urea
uric acid
Ammonia
- very soluble in water and highly toxic
- excreted generally by organisms that live in water, including hydra and fish
Urea
- not as toxic as ammonia
- excreted by earthworms and humans
- in mammals, it’s formed in the liver from ammonia
Uric Acid
- pastelike substance that that is not soluble in water and therefore not very toxic
- excreted by insects, many reptiles, and birds, with a minimum of water loss
Organism: hydra
Structure:
Nitrogenous Waste:
none
ammonia
Organism: platyhelminthes (planaria)
Structure:
Nitrogenous Waste:
flame cells
ammonia
Organism: earthworms
Structure:
Nitrogenous Waste:
nephridia (metanephridia)
urea
Organism: insects
Structure:
Nitrogenous Waste:
malpighian tubules
uric acid
Organism: humans
Structure:
Nitrogenous Waste:
nephrons
urea
Where does digestion occurs in cnidarians like hydra and jellyfish?
gastrovascular cavity which only has 1 opening, the mouth
The animal (hydra-cnidarians) has a 2-way digestive tract meaning
food enters the same opening as waste exists
Hydra-phylum cnidaria
Cells of the gastrodermis (lining of the gastrovascular cavity or gastrocoel)
secrete digestive enzymes into the cavity to aid in extracellular digestion (where the main part of digestion occurs)
Since the cnidarians are animals, their cells
contain lysosomes that carry out intracellular and extracellular digestion
What is the basic body plan of the hydra? of the jellyfish?
polyp
medusa
Symmetry of cnidarians
primitive and radial
Cell layers of Cnidarians
2 cell layers, ecto and endoderm
layers are held together by mesoglea (middle glue)
Why doesn’t the hydra need a circulatory system?
every cell is in direct contact with its environment
All cnidarians have cells called cnidocytes that contain
stingers, called nematocysts
Explain the nervous system of cnidarians
response to environment is controlled by a primitive nervous system, a nerve net, where impulses travel in all directions from any site
-as a result, entire animal responds to a single stimulus
How do cnidarians reproduce?
sexually and asexually by budding
What’s budding
a bud is a genetically identical but miniature version of the parent that forms within or on the parent, ultimately it breaks free
The digestive tract of the earthworm is
a long, straight tube
Earthworm digestion - Step 1
mouth ingests decaying organic matter along with soil
Earthworm digestion - Step 2
from the mouth, food moves to the esophagus and then to the crop, where it is stored
Earthworm digestion - Step 3
the gizzard which consist of thick muscular walls, grinds up the food with the help of sand and soil, which were ingested along with the organic matter
Earthworm digestion - Step 4
the rest of the digestive tract consists of the intestines where chemical digestion and absorption occur
What is absorption in earthworms enhanced by?
the presence of a large fold in the upper surface of the intestine, called the typhlosole, which greatly increases the surface area
How does the exchange of respiratory gases work in earthworms?
occurs passively by diffusion through the moist skin
earthworm are said to have an external respiratory surface because diffusion of these gases occurs at the animal’s surface
Earthworm’s Circulatory System- heart
-heart consist of 5 pairs of aortic arches that pump blood through arteries, veins, and capillaries
Why do we think the earthworm has a closed circulatory system?
since blood never normally leaves these blood vessels
The brain of the earthworm consists of
2 dorsal, solid, fused ganglia that connect to a solid, ventral nerve cord
The earthworm has paired ________ ub every body segment to remove the nitrogenous waste urea
nephridia
Earthworm reproduction
earthworm is a hermaphrodite
Grasshopper’s Digestive Tract
consists of a long tube consisting of a crop and a gizzard
Grasshopper has specialized mouthparts for
tasting, biting, and crushing food
Grasshopper has a gizzard that contains
plates made of chitin that help grind food
Grasshopper digestive tract is also responsible for removing
nitrogenous waste uric acid from the animal
-malpighian tubules
Grasshopper circulatory system - heart
-heart is tubular and animal lacks capillaries
Grasshopper has an
open circulatory system where blood normally leaves the artery and moves through interconnected sinuses or hemocoels (spaces surrounding the organs)
Arthropod blood doesn’t carry
hemoglobin or oxygen
Grasshopper/Arthropods&Crustaceans Respiratory system
internal respiratory surface because exchange of oxygen and CO2 occurs inside the animal
In an internal respiratory surface,
air enters the body through spiracles and travels through a system of tracheal tubes into the homecoels or sinuses, where diffusion occurs
In arthropods and some mollusks, oxygen is carried by
hemocyanin, a molecule similar to hemoglobin but with copper, instead of iron, as its core atom
