Exam 3 Flashcards
What is morphogenesis?
The combination of gastrulation and organogenesis that results in an organism’s shape and body orientation.
What is the cortical granule
Structure in the egg that releases enzymes during fertilization that harden the zona pellucida and digest binding proteins on sperm to prevent polyspermy.
What is the zona pellucida/jelly coat?
structure in the egg that contains glycoproteins that protect the inner contents of the ovum until the acrosome reaction of fertilization and helps prevent polyspermy.
What is the vitelline layer?
Protects and gives shape to the egg yolk, protecting it from the egg white.
What is the acrosome?
Organelle in the sperm head that contains enzymes that will degrade the zona pellucida, allowing the sperm to reach the egg plasma membrane.
What is the fertilization envelope?
A layer that prevents additional sperm from reaching the egg; the egg’s “slow block”
What is special about the cleavage stage?
Cell division in the zygote does not equal an increase in size.
What are blastomeres?
Smaller cells within the zygote
When does a zygote become a blastula?
After over 100 blastomeres have been produced.
What is considered to be the first embryonic tissue?
the blastoderm
What is the fluid or yolk filled cavity that the blastoderm surrounds?
the blastocoel
What is the mammalian blastula called?
The blastocysts
What is the trophoblast?
The outer cell mass of a blastocyst
What will the inner cell mass become?
the embryo
What will the trophoblast become?
the embryonic placenta
Where do the morula and blastocyst stages take place?
The uterus. After that, all other processes happen in the uterine tube.
What are intrinsic factors?
Information inherited from the mother cells free-floating cytoplasmic molecules
What are extrinsic factors?
Information received from the cells surrounding environment
Define lateral, medial, dorsal, ventral, anterior, and posterior
left-right-back-front-head-feet
What are cytoplasmic determinants?
mRNA proteins found in the egg prior to fertilization
What is yolk polarity?
The area with the least amount of yolk will become the anterior of the embryo
What is induction in mammal embryo development?
cell-cell communication
What is the process of cleavage?
Rapid, multiple rounds of mitotic cell division where the overall size of the embryo does not increase.
What is the blastula?
The developing embryo following cleavage
What is gastrulation?
The dramatic rearrangement of cells in the blastula to create the embryonic tissue layers.
What is organogenesis?
the process of organ and tissue formation via cell division and differentiation.
What are the 3 germ layers?
endoderm, ectoderm and mesoderm
Describe the endoderm
Form the guts of the embryo
What is the opening that forms the endoderm? What does it become in protostomes? what does it become in deuterostomes?
The blastopore….mouth…anus.
Describe the ectoderm
Completely surrounds the embryo and gives rise to the nervous system and the epidermis.
Describe the mesoderm
In between endo- and ecto-derm, gives rise to muscle cells and connective tissues
Which amniotes lay eggs?
Birds and reptiles
What are extra-embryonic tissues? What are the 4 extra-embryonic tissues?
tissues derived from the embryo that are not part of the body of the developing embryo.
Chorion, amnion, allantois, yolk sac
describe the chorion
surrounds the embryo and yolk sac, facilitating the exchange of 02 and co2 between the embryo and the external environment.
Describe the amnion
Inner amniotic membrane that surrounds the embryo and encloses the aqueous environment the embryo develops in
Describe the allantois
Stores nitrogenous waste produced by the embryo and facilitates respiration with the chlorion
Describe the yolk sac
Encloses the yolk and transports nutrients from the yolk to the embryo.
Does the nervous system originate from endo-, meso-, or ectodermal tissue?
Ectodermal
What will go on to become the nervous system?
the Neural plate
What is the notocord?
a rod-shaped mesodermal structure that signals the neural plate cells to form the neural tube and later forms part of the discs between vertebrae.
What does the neural tube give rise to?
the brain and spinal cord
What are neurons?
Specialized cells that can send and receive chemical or electrical signals
What two structure form the myelin sheaths?
Oligodendrocytes and Schwann cells
What are neurotransmitters?
chemical messengers that communicate between adjacent neurons
what are the 3 different classes of neurons in the CNS?
sensory, motor and interneuron
Describe sensory neurons
AKA affarent, get info about whats going on outside the body and bring that info to the CNS so it cna be processed
Describe motor neurons
AKA efferent, get info from other neurons and convey commands to muscles, organs and glands.
Describe interneurons
Only found in the CNS, they connect one neuron to the next, sending and receiving info between neurons.
What is white matter?
Myelinated axons positioned inward on the brain
What is gray matter?
Unmyelinated axons and cell bodies usually facing outward.
What composes the CNS
Brain and spinal cord
What composes the PNS?
Peripheral sensory and motor nerves
Describe mechanoreceptors
sensory cell that responds to physical deformation of the cell membrane from mechanical energy or pressure
Describe chemoreceptors
sensory cell that responds to specific molecules
describe photoreceptors
sensory cells that respond to radiant energy (visible or UV light)
describe thermoreceptors
sensory cells that respond to heat or cold
describe nociceptors
respond to noxious stimuli, anything that can cause tissue damage.
Describe a hydrostatic skeleton
type of skeleton that has a closed, fluid filled compartment called the coelom and where movement is provided by muscle that surround the coelom
Describe exoskeletons
an external encasement of hard material made up of chitin and sometimes calcium carbonate.
Describe endoskeletons
skeletons consisting of hard, mineralized structures located within the soft tissue of an organism
Dsecribe ingestion
taking in of food through the mouth
Describe ingestion
mechanical and chemical breakdown of food into smaller organic fragments
describe absorption
the diffusion and intake of nutrients from food into the metabolic systems of the body.
describe elimination
expulsion of undigested food
Describe gastrovascular cavities, or incomplete digestive tracts
One opening, passive digestion and absorption
Describe alimentary canals, or complete digestive tracts
a tube with a mouth and an anus
What does monogastric mean?
Single stomach
How are avian digestive tracts unique?
No mastication, gizzards, crops and cloacas
How are ruminants different and why?
They have multichambered stomachs to deal with the high amount of cellulose in their diet.
What is a hermaphroditic organism?
Has both male and female reproductive organs
What is neurulation?
The fusing of the neural plate into the neural tube
What is parthenogenesis
Reproduction from an unfertilized egg cell.
All cells of an organism find their lineage from the same cell called a…
zygote
What is the general life cycle of animals?
zygote->diploid individual->meiosis->gametes->fertilization
Sequence of embryonic development
fertilization->cleavage->neurulation->-gastrulation->organogenesis
The 3 germ layers of tribloblasts are established during…?
gastrulation
What is the correct sequence of events in embryonic development?
Fertilization->cleavage->gastrulation->organogenesis
Compared to external fertilization, in internal fertilization…?
male gametes have a higher chance to come into close proximity to female gametes
Germ layers are…?
embryonic layers with different developmental potentials.
All cells of an organism find their lineage from a single, fertilized cell. This single fertilized cell is called a…?
Zygote
Does the blastopore occur in just protostomes, just deuterostomes or both?
Both
The type of skeletal system that involves fluid-filled body compartments and does not have any hard structures is called a(n)…
hydrostatic skeleton
The central nervous system of vertebrates consists of…?
the brain and the spinal cord.
How do sensory cells communicate different types of information to the brain?
By using different neurons for different stimuli (i.e. light vs tough)
What class of nervous system cells carry nerve impulses?
Neurons
What class of nervous system cells provide support and protection?
Glial cells
The simplest nervous system found in nature is the nerve net. An example of an organism that senses and responds to its environment with this ancient system would be a…?
jellyfish.
Birds store food in a modified portion of the lower esophagus called the…?
crop.
Cows are able to survive on a diet consisting almost entirely of cellulose because…?
Cows have cellulose-digesting, symbiotic microorganism in their ruemen.
What is the gizzard in birds?
the “stomach”
True or false: smaller mammals typically have a higher ventilation rate than larger mammals?
True
If the efficiency of the alveoli in a human was reduced by 50?
The rate of gas exchange would decrease by 50%
How does oxygen transport to cells in open circulatory systems?
The oxygen diffuses directly across the respiratory surface.
What is the main difference between an open and closed circulatory system?
The structure and design of the vessels
Do grasshoppers have an open circulatory system?
Yes
What are the only vertebrates in which blood flows directly from the respiratory organs to body tissues without first returning to the heart?
Fishes
Animals in which the circulating fluid is physically separated and chemically distinct from the fluid that directly surrounds the bodies cells have a(n)…?
closed circulatory system.
How do birds get rid of toxic ammonia?
Uric acid
What are the excretory organs found in insects?
Malphighian tubes
The three major forms of nitrogenous waste are…?
Ammonia, urea and uric acid
Ecdysis is…?
Molting of the exoskeleton
Organisms found in the group ecdysozoans have at least one thing in common. What is it?
Molting
Which phylum includes organisms with a muscular foot, visceral mass, and mantle?
Mollusca
This is the motile stage of cnidarians during which only sexual reproduction occurs.
Medusa
All animals are…?
Multicellular, heterotrophic, and diploid
Which of the following organisms (sea sponges, nematode, planaria, or jellyfish) have specialized cells but no tissue?
Sea sponge
Are earthworms bilaterally or radially symmetrical?
Bilaterally
Are jellyfish bilaterally or radially symmetrical?
Radially
What are the key characteristics of phylum Chordata?
Pharyngeal slits, dorsal hollow nerve cord, notochord, post anal tail
Planaria are what phylum?
Platyhelminthes
What phyla do humans belong to?
Chordata
Which of the following are considered deuterostomes, where the blastopore develops into the anus? Starfish Gorillas Ducks Jellyfish Humans Spiders Rotifers
Starfish, gorillas, ducks, and humans
Animals capable of producing their own body heat by way of metabolism and retaining it are said to be…?
endothermic
Do fish have amniotic eggs?
No
What are tetrapods?
All amphibians, reptiles, birds, and mammals
What are osteichthyes?
Bony fish
What are Mammalia?
Vertebrate animals where the young are nourished with milk from special mammary glands of the mother.
What are Chondrichthyes?
Cartilaginous fish
What are Squamata?
scaled reptiles like lizards, snakes, and snake-like lizards
What clades are endothermic?
Mammalia as well as birds
Chickens are more closely related to crocodiles than stingrays or lizards
Okay. What a dumb fucking question
Why are leech mouths shaped the way they are?
So it can parasitically cling to its host.
What kind of diet might an organism with large canine teeth have?
Carnivorous
Vertebrates are a subphylum within the phylum…?
Chordata
Mammals have a fluid-filled body cavity called a…?
Coelom
The nearest living relatives of crocodiles and alligators are…?
Birds
Reptilian embryos will not dry out in a desert habitat because…?
reptiles produce shelled amniotic eggs
Which of the following characteristics would be true of an epithelium specialized for exchange by diffusion?
Thin with large surface area (maybe, not 100% sure on this)
In general, for mammals, the vessels that carry blood away from the heart in a closed circulatory system are referred to as ______ and vessels carrying blood to the heart are _____. Where veins and arteries meet, _____.
Arteries (away), veins (to), capillaries
Why do birds excrete uric acid instead of the other forms of nitrogenous waste?
As a way to save water and keep their body weight low.
Do to your innate immune system, bacteria are attacked by _____ _____ cells
leukocytes, phagocytic
A new organism is found that is a deuterostome but has radial symmetry. It is likely an…?
Echinoderm (starfish, crinoids, sea urchins, etc)
What are totipotent stem cells?
A single cell that can give rise to all extra-embryonic tissues (totally potent)
What is a pluripotent stem cell?
A stem cell that can develop into the 3 germ layers of the early embryo, but not extra-embryonic tissue
What is a multipotent stem cell?
A stem cell that can develop into multiple specialized cell types in a specific tissue layer.
What are deuterostomes?
An organism where the blastopore develops into the anus.
What are protostomes?
An organism where the blastopore develops into the mouth.
What does it mean to acoelomate?
No body cavity enclosed by the mesoderm
What does it mean to be pseudocoelomate?
Body cavity partly enclosed by the mesoderm, but organs/system not separated.
What does it mean to be coelomate?
Body cavity enclosed, organs/organ systems separated by mesoderm.
What makes an arthropod different from ecdysozoa?
Molting
What are external gills?
Gills that can be pulled inside to an extent and are only protected part of the time.
What are internal gills?
Fully internal gills, able to be exposed but less so than external gills.
What all comprises a system?
Organs (multiple), tissues, cells, etc
What is the difference between a complete digestive system and an incomplete one?
Complete digestive systems have multiple organs and are connected mouth to anus
What is the basal metabolic rate?
Endothermic homeostasis needed to stay alive, not including activity, in endotherms
What is the standard metabolic rate
BMR for ectotherms
What leads to a higher BMR?
High surface area with small size (size shrews)
What are thermoreceptors?
Neurons that sense temperature
What are chemo-receptors?
Neurons that sense chemicals
What are mechanical receptors?
Neurons that sense physical stimuli, as well as things like wavelength.
