Biology Exam 4

What is a monophyletic group

a collection of organisms that share a common ancestor and all of its descendants

What two synapomorphies distinguish the monophyletic group of vertebrates

vertebrae and cranium

What side of the body would one expect the vertebrate to form?

the dorsal side

When and where was the latest great migration

south america, 15,000

What is Amniota

Amniota is a lineage of vertebrates that includes all tetrapods other than amphibians.

Amniotes signature synapmorphy and adaptation is:

the amniotic egg

When were tetrapods first identifiedd in the fossil record

about 20 million years ago

Almost all of the reptiles living today do not use internally generated heat to regulate their body temperature—this is called

ectotherms ( outside-heated )

Birds regulate their body temperature using——

endotherms—- inside-heated; maintaining a high body temperature by producing heat in their tissues

What two subphyla in Chordata are invertebrates

Cephalochordate and Urochordata

Lanceletes are a part what subphyla

Cephalochordata —-phyla chordata

Lancelets feeding

suspension feeding- adults extend their head out of sediments, pumping water through the mouth and trapping food particles in mucus on pharyngeal slits

Urochordates examples

sea squirts, salps, and larvaceans

Urochordates reproduce by

most release both eggs and sperm, but some retain eggs for internal fertilization; some form large colonies via asexual budding

What structures are homologous to pharyngeal gill slits and are present in all vertebrate embryos

Pharyngeal pouches

In early vertebrates, the front region of the brain name and function is…

Forebrain and sense of smell

n early vertebrates, the middle region of the brains name and function is…

the midbrain and vision

In early vertebrates, the back region of the brain’s name and function is…

the hindbrain and balance and some species hearing

What adaptive radiation gave rise to today's diversity of mammalian orders didnt take place until after what event?

The extinction of dinosaurs

Among vertebrates, what are the most species-rich and ecologically diverse lineages are

ray-finned fishes and the tetrapods

What are the three monophyletic groups of mammalia

monotremata, marsupiala and Eutheria

What is the adaptive advantage of a nerve net in radial symmetric animals

it allows them to sense prey approaching from all sides of the body

Primary example of a nerve net demonstrated in cnidarian

anemone

Cephalization is

the concentration of neurons and sense organs in a head region

What type of symmetry and nervous system promote movement in a single direction?

Bilateral symmetry and central nervous system

Ovoviviparous offspring are

housed within but NOT nourished by the mother; nourished from the egg

Oviparous offspring are

nourished by the egg and not housed within the mother

Viviparous reproduction is

housed within and nourished by the mother

What is the distinguishes a coelomate from a pseudocoelomate?

Coelomates have a body cavity completely lined by mesodermal tissue, whereas pseudocoelomates dont

What characteristic traditionally applies to protostome development

the blastopore becomes the mouth

development of the mouth before the anus

deuterstomes are names for

the embryonic development of the anus before the mouth.

How do flagella of choanocytes work

they beat in a coordinated way to produce a water current that flows through small pores in the body cavity and out through a single large opening

What is the Shannon diversity index an estimate of

species richness, abundance, and eveness

The principle of competitive exclusion states that:

two species that have exactly the same niche cannot coexist in a community

Which of the following studies would a community ecologist undertake to learn about competitive interactions?

 

I) Selectivity of nest sites among cavity-nesting songbirds

II) The grass species preferred by grazing pronghorn antelope and bison

III) Stomach analysis of brown trout and brook trout in streams where they coexist

All of the above, investigate competitive interactions among species

competition for nesting sites, herbivore resource and prey resource

Why was Pisaster ochraceus used as a keystone species by Robert Paine

sea stars are top predators that have a large impact on the community via there massive consumption of mussels.

What is Batesian mimicry

one species does not posses a certain defensive trait, yet are not dangerous

What is the bottom-up limitation hypothesis

it refers to population regulation being dictated by resource such as plants..assuming that plants offer poor nutrition and are well defended

Niche differentiation can result in

character displacement

What is the difference between primary and secondary succession

Secondary succession occurs when the disturbance leaves the soil intact, whereas primary succession occurs when there is no intact soil

Primary succession is

he process of completely starting an area over with nearly all organisms being removed, even those present in the soil.

occurs on rock outcrops, beach dunes, and the exposed substrate as glaciers retreat.

Secondary Succession occurs

when the soil and some species stay intact following the disturbance.

following a disturbance such as a fire or land that was cleared for agriculture and is subsequently abandoned.

What taxon is more closely related to Bacteria, archea or eukarya

neither, they are equally related

Compare Homology and Homoplasy

Both are evolutionary processes that explain how different species have similar traits

Contrast homology and Homoplasy

homology refers to traits derived from a common ancestor while homoplasy indicates traits with similar functions or appearances but different evolutionary origins

compare Mass and Background Extinctions

exctinction is when a species or other taxonomic group is wiped out, removed from the tree of life

contrast mass and background extinctions

mass extinctions are rapid and affect many species globally while background extinctions are gradual affecting fewer species locally

Genetic Drift and Gene Flow compare

both are evolutionary process that drive changes in allele frequencies

Genetic Drift and Gene flow contrasted

Genetic drift is random changes in allele frequencies; it is important in small populations and tends to reduce genetic variation

. Gene flow is the movement of alleles between populations. may increase or decrease genetic variation

What is the sister group of animals/eukaryotes?

choanoflagellates

Animals form a monophyletic clade with what key traits:

Multicellularity, with cells that: lack cell walls, have an extensive ECM, life cycle is diploid dominant

Extracellular matrix are

fiber composites for structure

The First node in the animal kingdom is

multicellularity,

lack cell walls

have an extensive ECM

Collagen cable-like proteins dominate the ECM

Choanoflagellates are

protozoans, that have a single flagellum with ring of tentacles

colonial organisms

What is the most ancestral group of animals

Sponges