Test 1

4.5 Billion years old

How old is the Earth?

3.5-3.8 Bilion years old

How old is life on Earth?

Over 600 million years ago

How long have animals been around?

the ability to: reproduce, homeostasis, communication, and response to change

Life on Earth can be defined as…

Eukaryotes, multicellular, and heterotrophs

What are shared traits of animals?

Theory 1: living world is always changing, and changes are passed on through heredity

Theory 2: common descent

Theory 3: multiplication of species over time

Theory 4: gradualism (phenotypic changes occur slowly and gradually)

Theory 5: natural selection (as a mechanism)

What are Darwin’s theories?

similarity attributable to common origin i.e. similarities between (groups of) organisms are explained by a shared common ancestor who passed on the trait

What is homology?

Traits shared by organisms, but due to similar life styles, not a recent common ancestor (wings in insects, birds, and bats)

What is homoplasy?

Two steps: (1) genetic phenotypic variation generated as the result of mutations, genetic recombination, gene shuffling, etc.

(2) sorting: survival of different traits (fitness)

How does natural selection work?

Changes in allele frequencies that lead to different traits within a population over time

What is microevolution?

Changes that lead to new species or taxa over time

What is macroevolution?

Genetic code (ATCG) being universal, and making up all forms of life

Evidence for single origin of life?

(1) Selection (natural and sexual)

(2) Genetic Drift: chance events

(3) Gene flow: migration of alleles (individuals) out of, into, or between populations

(4) Mutations

List the four evolutionary forces

Change of allele frequencies in a population over time

Definition of evolution (modern context)

(1) Protoplasmic: complete organism that can perform all functions of life

(2) Cellular: cells are not capable of independent existence, cells are differentiated and have specific functions

(3) Cell-tissue: aggregation of similar cells into patterns of layers that perform common function

(4) Tissue-organ: aggregation of tissues into larger functional units

(5) Organ system: organs work together to perform a function

Name the five grades of hierarchal animal complexity, and briefly describe them

(1) medial: midline

(2) lateral: sides

(3) ventral: lower (belly)

(4) dorsal: upper (back)

(5) anterior: toward the front

(6) posterior: toward the back

(7) proximal: describes a body part that is close to a point of attachment than another body part

(8) distal: describes a body part that is farther away from a part of attachment than another body part

(9) transverse plane: cross section, anterior and posterior

(10) frontal plane: divides in ventral and dorsal

(11) sagittal plane: divides in left and right

List the terms for body symmetry and what they refer to (11)

zygote →mitosis →(1) morula (ball of cells, no cavity yet)→ (2) blastula (fluid filled cavity and blastoderm)→ (3)gastrula (one side pushes inward and becomes a gut cavity)

Describe the names given to the formulation of body cavities, and briefly describe what they refer to

(1) endoderm: inner layer

(2) ectoderm: outer layer

(3) mesoderm: middle layer

List the 3 germ layers and describe where they are referring to

Diploblastic: Diploblasts possess only two germ layers (endoderm and ectoderm)

Triploblastic: Triploblasts possess a third layer in addition to the two other layers (mesoderm)

What are diploblastic and triploblastic organisms

ASK BECKERSSSS

Describe the development of body cavities

Mesodermal cells completely fill the blastocoel. The cell filled room is called the parenchyma

Define acoelomate

Mesodermal cells line outer edge of blastocoel; two cavities: blastocell (=pseudocell) and gut

Define pseudocoelomate

Mesodermal cells grow as pouches that eventually pinch off and form a true coelom

Define entercoely

Mesoderm cells fills blastocell with band of tissue that then opens up in center and then forms true coelem

Define schizocoely

Embryonic blastopore develops into the mouth, and a second opening later forms the anus. Undergo spiral cleavage

Define a protostome and the type of cleavage they have

Blastopore develops into the anus, while the mouth forms later as a second opening. Undergo radial cleavage

Define a deuterostome and the type of cleavage they have

Epithelial, connective, nervous, and muscle tissues

What are the four types of tissues?

(1) Morphological (typological) species concepts

(2) Biological species concept

(3) Genetic species concept

What are the 3 species concepts?

species are defined by morphological features (shape, size, color, etc)

Problems: species show variation, and do change through time to some degree

Define the morphological species concept, and problems with it

Species are groups of interbreeding natural populations that are reproductively isolated from other such groups (viable and fertile offspring)

Problems: extinct species, asexual reproduction

Define the biological species concept, and problems with it

Geneticist’s equivalent of the morphological concept, but genetic similarity is used

Problems: how much genetic difference constitutes separate species?

Define the genetic species concept, and problems with it

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

List the 7 taxonomic ranks in sequence

Character that was present in common ancestors of all species in taxon

What is an ancestral trait?

Variants that arose later in the group

What is a derived trait?

Derived characteristic shared by all members of a clade. Just a new trait

Define synapomorphy

Ancestral shared characteristic of taxon. Old trait

Define symplesiomorphy

This is a monophyletic grouping. Taxon includes most recent common ancestor and all descendants of that ancestor

What kind of phyletic groups are highlighted yellow? Explain it

This is a paraphyletic grouping. Taxon includes most recent common ancestor but not all descendants of that ancestor

What kind of phyletic groups are highlighted blue? Explain how it works.

This is a polyphyletic grouping. Taxon does not include most recent common ancestor of all members of the group. Group has at least two separate origins, traits that are similar evolved independently

What kind of phyletic groups are highlighted red? Explain how it works.