,Zoology
Chapter 1: Life: Biological Principles and the Science of Zoology
General properties of Living Systems:
1. Chemical uniqueness
2. Complexity and hierarchical organization
3. Reproduction
4. Possession of a genetic program
5. Metabolism
6. Development
7. Environmental interaction
8. Movement
MRS. GREN
Chapter 2: Origin and Chemistry of Life
2.4 Origin of Living systems
Earliest form of life ~ 4 billion years ago
Catalytic RNA (ribozymes) can mediate processing of messenger RNA and can catalyze
formation of peptide bonds. The earliest enzymes probably were catalyzed by their RNA.
Autotrophs produce their own food from inorganic sources. Heterotrophs must obtain their
food supplies from their environment.
Photosynthesis: 6 CO2 + 6 H2O → C6H12O6 + 6 O2
Oxidative metabolism: recovering energy stored in the bond energy of glucose produced
by photosynthesis.
2.5 Precambrian life
~542 million years ago
Cambrian explosion: appearance of many species
Cyanobacteria: oxygen-producing bacteria.
Prokaryotes contain a single, large molecule of DNA not located in a membrane-bound
nucleus, but in a nucleoid.
Eukaryotes have cells with membrane bound nuclei containing chromosomes composed
of chromatin, including proteins called histones, RNA and DNA.
Endosymbiosis theory: anaerobic bacteria developed a nucleus and other intracellular
membranes from infoldings of the cell membrane.
Chapter 6: Organic Evolution
6.2 Darwinian Evolutionary Theory: The Evidence
Radioactive decay can be used to determine the age of fossils.
Phylogeny: branching tree which shows descent from a common ancestor.
Homology: the same organ in different organisms under every variety of form and function.
They provide evidence of a common ancestor.
,Multiplication of Species
Reproductive barriers prevent different species from interbreeding.
● Allopatric speciation
○ Separation of geographical areas prevents interbreeding
○ Vicariant speciation (climate or geological change)
○ Founder event (individuals establish a new population where no individuals
of their species are located yet)
Hybridization: production of hybrids by intercrossing two different populations.
Mating barriers can be premating (impair fertilization) or postmating (impair growth and
development, survival or reproduction of the hybrid).
● Non Allopatric speciation
○ Sympatric speciation: different individuals within a species become
specialized for occupying different components of the environment.
○ Parapatric speciation: intermediate allopatric and sympatric speciation, as
their geographical ranges border each other, but the species don’t quite cross
this borderline.
Adaptive radiation: evolution of several ecologically diverse species from a common
ancestral species.
Punctuated Equilibrium
Phyletic gradualism: a long series of intermediate forms connecting the phenotypes of
ancestral and descendant populations.
Punctuated equilibrium: explains discontinuous evolutionary changes observed throughout
geological time. A small fraction of the evolutionary history of a group contributes most of the
morphological evolutionary change observed.
Natural selection: adaptation, including developmental, behavioral, anatomical and
physiological attributes that enhance an organism’s ability to use environmental resources to
survive and reproduce.
Exaptation: the utility of a structure for a biological role that was not part of the structure’s
evolutionary origin. (e.g. wings adaptations for thermoregulation but exaptations for flight)
Neo-Darwinism: revised theory, in which the modifications of an organism during its lifetime
do not change its heredity.
Chapter 9: Architectural Pattern of an Animal
9.2 Animal body plans: Animal symmetry
Spherical symmetry: plane passing through the center divides a body into equivalent, or
mirrored, halves. Rare in animals, best suited for floating and rolling.
Radial symmetry: can be divided into similar halves by more than two planes passing
through the longitudinal axis (tubular, vase or bowl shapes).
Biradial symmetry: mirrored halves when two planes through a longitudinal axis.
Radial and biradial are usually sessile, freely floating, or weakly swimming organisms:
radiata.
Bilateral symmetry: can be divided along a sagittal plane into two mirrored portions. They
are better fitted for directional (forward) movement: bilateria.
Bilateral symmetry is associated with cephalization.
, Chapter 10: Taxonomy and Phylogeny of Animals
10.1 Linnaeus and Taxonomy
Kingdom, phylum, class, order, family, genus, and species.
Classification: defined by possession of an essential characteristic
Systematization: constitute a system of common descent.
Linnaeus → binomial nomenclature: Genus + species epithet
10.3 Taxonomic characters and phylogenetic reconstruction
Homology: character similarity that indicates common descent
Homoplasy: character similarity that does not indicate common descent
From the ancestral character state, derived character states arise.
All ingroup character states that are absent from appropriate outgroups are considered
derived.
A clade is a fundamental unit of phylogenetic grouping of species: ancestral lineage and all
species descended from that lineage.
Synapomorphy: derived character shared uniquely by all members of a clade.
Plesiomorphic: character states ancestral for a taxon.
Symplesiomorphy: the sharing of ancestral states among species.
Cladogram: nested hierarchy of clades forming a branching diagram.
Phylogenetic tree: branches represent real lineages that occured in the evolutionary past.
Comparative morphology: examination of varying shapes and size of organismal
structures, including their developmental origins (macro and micro).
Comparative biochemistry: uses sequences of amino acids in proteins and the sequences
of nucleotides in nucleic acids to identify variable characters for constructing a cladogram.
Comparative cytology: uses variation in the numbers, shapes, and sizes of chromosomes
and their parts to obtain variable characters for constructing cladograms (living organisms).