FINAL EXAM Flashcards
Explain why scientists use scientific names instead of common names
It uses same language (Latin or some Greek) for all names so that it is universally understood
Describe the scientific system of naming organisms
- Scientists use a two-name system called a Binomial Naming System
- Scientists name animals and plants using the system that describes the genus and species of the organism
- The first word is the genus and the second is the species
- The first word is capitalized and the second is not.
Evaluate the role of Linnaeus in creating the modern system of naming organisms
- 18th century taxonomist
- Classified organisms by their structure
- Developed naming system still used today
- Called the “Father of Taxonomy”
- Developed the modern system of naming known as binomial nomenclature
Explain how to write a scientific name using binomial nomenclature
- Genus species
- Latin or Greek
- Italicized in print
- Capitalize genus, but NOT species
- Underline when writing
How does the classifying of living things reflect their evolutionary history
Two species within the same genus likely share a recent common ancestor in their evolutionary history.
List in order, the 7 levels of biological classification
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
Summarize characteristics that biologists use to classify organisms
Physical features, the fossil record, and DNA sequences
Summarize the biological species concept
It determines what organisms are part of a species. According to this concept, a species is defined as a group of organisms that can successfully interbreed and produce fertile offspring.
Explain how a cladogram is constructed
by grouping organisms together based on their shared derived characteristics.
Describe how biologists use cladograms to determine evolutionary histories
By putting emphasis on derived characters and recognizing ancestral characteristics, scientists can compare different phylogenies of the same groups of organisms.
Interpret a dichotomous key
To use the key, the scientist starts at the top, or beginning, and sees which of the two options apply to their organism. Based on their answer, the key directs them to a new question. They continue in this way until reaching an endpoint, the name of an organism.
Identify unifying characteristics of all animals
- eukaryotic
- multicellular organisms
- heterotrophs
Recognize the advantage of multicellularity
- Intelligence and evolution
- organisms are larger
- multiple cells will perform multiple different functions
- longer lifespan
Contrast the body plans of asymmetrical, radially symmetrical, and bilaterally symmetrical animals
RADIAL SYMMETRY
body parts are arranged around a central axis
BILATERAL SYMMETRY
organisms can be divided into two near-identical halves along a single plane
ASYMMETRY
absence of balanced proportions
List three structures derived from mesoderm
muscle, bone, connective tissue
Describe the advantage of a one-way gut
allows for efficient processing of food and absorption of nutrients.
Contrast the three kinds of body cavities
- Acoelomate: no body cavity
- Pseudocoelomate: partial body cavity
- Coelomate: true body cavity
Analyze how animal body plans are related to phylogeny
Anatomical features in animals’ body plans mark the branching points on the evolutionary tree
Summarize the difference between protostomes and deuterostomes
how they develop in the early embryo stages. In protostomes the mouth opening is the first to be formed later followed by the anus. In deuterostomes the anus forms first followed by the mouth. This all occurs in the gastrulation stage.
Distinguish among the stages of embryonic development in animals
Fertilization → Zygote → Cleavage → Morula → Blastula → Gastrula
The zygote undergoes a series of cell divisions (called cleavage) to form a structure called a morula. The morula develops into a structure called a blastula through a process called blastulation. The blastula develops into a structure called a gastrula through a process called gastrulation.
Identify the structures in sponges and their function
Osculum - current of water exits
Spicules - structural support
Mesohyl - maintains sponge’s shape
Porocyte - control the amount of water that enters pores
Pinacoderm - forms an external barrier to protect it from the outer environment
Spongocoel - nutrition
Amoebocyte - regeneration and in transportation of food particles
Inhalant pore - water enters and exits the sponge
Choanocyte - aid the movement of water through the sponge
Evaluate the importance of sponges to humans
Sponges filter the water and improve its quality
Describe the differences among the various types of sponges
Distinguish between asexual and sexual reproduction in sponges
ASEXUAL
- Budding: A part of the sponge grows off the parent, eventually becoming a new sponge
- Fragmentation: A part of the sponge breaks off, settles on the seafloor, and forms a new sponge
- Gemmules: Gemmules are sphere-shaped groups of amoebocytes surrounded by a tough layer of collagen (spongin) and spicules.
SEXUAL
- Sponges are monoecious or hermaphroditic, meaning each sponge forms both sperm and eggs
- Eggs are kept inside the sponge
- Sperm are released into the water that takes it to another sponge of the same species, where it will enter and fertilize an egg
- Egg develops into a larva which is eventually released from the sponge
Describe the two cnidarian body forms
There are two basic cnidarian body shapes: a polyp form, which is attached to a surface; and an upside-down free-floating form called a medusa
Describe the general characteristics of cnidarians
- Radial symmetry
- Hollow gut
- Gastrovascular cavity has a single opening
- Two tissue layers (diploblastic)
- Outer epidermis and inner gastrodermis
- Either polyp or medusa shaped
- Tentacles surround mouth
Summarize how cnidocytes function
Cnidarians have a stinging cell called the cnidoblasts or nematocysts. These cnidoblasts are deployed by the tentacles that end or retract toward the mouth. Each of the cnidoblasts has a capsule with a coiled threat that can be forcefully ejected and contains a toxin or immobilizing prey.
Compare the three classes of cnidarians
ANTHOZOA
- only polypoid
SCYPHOZOA
- predominantly medusoid
HYDROZOA
- the most primitive, both body forms are generally developed
Compare asexual and sexual reproduction in cnidarians
polyps primarily reproduce asexually by budding, however, some produce gametes (eggs and sperm) and reproduce sexually. Medusae usually reproduce sexually using eggs and sperm
Describe the general characteristics of flatworms
- Acoelomate
- Bilateral symmetry
- Show cephalization
- Respiration through skin
- Single opening to digestive tract (pharynx)
Explain how flatworms maintain homeostasis
Compare the three classes of flatworms
TURBELLARIA
- Spade (shovel)-shaped head and two eyespots
- Eat protozoans for scavenge
- Flame cells remove waste
- Are hermaphrodites
- Can reproduce by regeneration
- Are free-living (not sessile)
TREMATODA
- Are parasitic flukes
- Have suckers on both ends of the body
- Can live inside or outside of host
- Nervous and excretory systems like turbellarians
- Hermaphrodites
- Have complex life cycles
CESTODA
- Parasitic
- Tapeworms
- Long, ribbon-like bodies
- Absorbs nutrients from host
- Hermaphrodites