1.Understand Concepts, Principles = Applications of Classical and Molecular Genetics

ROUGH DRAFT

Competency 0012

1.Understand concepts, principles = applications of classical and molecular genetics.

A. Analyze the significance of Mendel’s pea experiments.

• Brought an experimental and quantitative approach – science as a process.
• By law of segregation, 2 alleles for a character are packaged into separate gametes.
• By law of independent assortment, each pair of alleles segregates into gametes independently.
• Mendelian inheritance reflects rules of probability.
• Discovered the particulate behavior of genes.

<Dominant allele: in a heterozygote, the allele is fully expressed.

<Recessive allele: in a heterozygote the allele that is fully masked.

Mendel cross-pollinated purple flowering pea plants with white flowering pea plants.

<Law of segregation: Independent assortment: specific application of the same general rules of probability for genetic analysis.

II. Analyze genetic inheritance problems involving genotypic and phenotopic frequencies.

<Phenotype: physical and physiological traits of an organism (appearance).

<Genotype: Genetic make-up of an organism, .thetype of genes an organism has for a trait

An organism’s appearance does not always reveal its genetic composition.

Population Genetics

Key – vocab

Key – concepts & principles

1. Allele – an alternate form of a gene

2.Gene pool – the total aggregate of genes in a population at any one time. It consists of all alleles at all gene loci in all individuals of the population.

3.Gene – a discrete unit of hereditary information consisting of a specific nucleotide sequence in DNA that codes for a trait.

4.Genetic drift – changes in the gene pool of a small population due to chance.

5.Genotype – the genetic make-up of an organism

6.Hardy-Weinburg Theorem – states that frequencies of alleles and genotypes in a population’s gene pool remain constant over the generation unless acted upon by agents other than sexual recombination. (The sexual shuffling of alleles due to meiosis and random fertilization has no overall effect on the overall genetic structure of a population. Provides a baseline for tracking deviations in a population over a succession of generations - (describes a gene pool in equilibrium) - non-evolving population)

7.Microevolution – a generation-to-generation change in a population’s allele or genotype frequencies.

8.Five causes of microevolution

A. Genetic drift – changes in the gene pool of a small population due to chance.

B. Gene flow-genetic exchange due to the migration of fertile individuals or gametes between populations.

C. Mutation – a change in an organism’s DNA. For any one-gene locus, mutation alone does not have much quantitative effect on a large population. Although mutations at a particular gene locus are rare, the cumulative impact of mutations at all loci can be significant.

D. Natural selection – differential success in the reproduction of different phenotypes resulting from the interaction of organism with their environment.

Competency 0013

Analyze adaptations as products of variation and natural selection.

Natural selection – Differential success in the reproduction of different phenotypes resulting from interaction of organisms with their environment.

Variationsresult from:

• mutations
• genetic recombination (sexual reproduction)
• environmental selection effects

Effect of Selection:

• Stabilizing selection acts against extreme phenotypes and favors the more common variants; i.e., stabilizes the status quo, i.e. human birth weights in 3-4 kg range. Smaller and larger babies have a greater infant mortality.
• Directional selection is most common during environmental changes or through migration. This shifts the frequency curve fora variation by favoring initially rare phenotypes, i.e.,size of bears in Europe increased with each glacial period of ice agesand decreased during warmer interglacial periods.
• Diversifying selection – occurs when environmental conditions are varied in a way that favors individuals on both extremes, i.e., finch population with two bill sizes.

Competency 0013

Analyze proposed mechanisms of evolution: (e.g., embryology, biochemistry, anatomy) in terms of evolutionary theory.

• Biogeography – geographical distribution of species
• Fossil record provides fossil evidence of changes in organisms over time
• Comparative anatomy - provides anatomical evidence of evolution – homologous structures aresimilar characteristics resulting from common ancestry, i.e., forelimbs of mammals arise from the same embryonic skeletal structures but are modified for different uses.
• Comparative embryology – closely related organisms go through similar stages in embryonic development, i.e., embryos show homology during development that are modified as adult structures (gill slits)

-Ontogeny – the embryonic development of an organism

-Phylogeny – evolutionary history of a species or related organisms

• Molecular biology – tools and techniques used to study evolutionary relationships based on DNA and proteins. A common genetic code among organisms is evidence that all life is related.

Competency 0014

Factors that contribute to speciation - origin (evolution) of a new species

Allopatric speciation is caused by:

• Geographical isolation – divides a population into two isolated populations which eventually diverge
• Adaptive radiation – evolution of several species with diverse adaptations from a common ancestor. Occurs in association with island chains such as the Galapagos Islands.

Sympatric speciation – occurs when species originate in the geographical midst of the parent species. Caused by a reproductive barrier between individuals of the mutant and the parent species.

Factors leading to Reproductive Isolation (the idea that organisms of the same species interbreed and populations belonging to different species do not interbred)

(Understand that a zygote occurs when the sperm of one organism fertilizes the ova of an organism of the same species, and restores the diploid number of chromosomes)

• Pre-zygotic barriers to reproduction impede mating between species and prevent fertilization of ova when members of different species do attempt to mate
• Habitat Isolation – two species that live in different habitats encounter each other rarely (and will prefer mates of their own species)
• Behavioral Isolation – courtship behaviors and sexual signals are species specific
• Temporal Isolation – Breeding typically occurs at differing times between related species preventing cross species mating
• Mechanical Isolation – Related species are anatomically incompatible for mating
• Gametic Isolation – Gametes of different species will rarely fuse to form a gamete at all.
• Post-zygotic Barriers occur when a sperm of one species does fertilize an ova of a different species, the hybrid zygote will seldom develop into an offspring

-Post-zygotic Barriers

- Reduce hybrid viability

- Reduce hybrid Fertility

- Hybrid Breakdown.

Competency 015

Taxonomy: Classification of Organisms

I. Linnaeus

A. Binomial nomenclature

1. Common

B. Taxonomy filing system for grouping species (broader to specific)

1.Domain

2.Kingdom

3.Phyla

Subphyla

4.Class

5.Order

6.Family

7.Genus

8.Species

1. Evolutionary history (Phylogeny)

Phylogenetic Trees – diagrams that trace evolutionary history

a)Monophyletic tree – a single ancestor gives rise to all species in that taxon and to no species in any other taxon

b)Polyphyletic – members of a taxon are derived from two or more ancestors not common to all members of the taxon

c)Prophylactic – a taxon excludes species that share a common ancestor that gave rise to the species in that taxon

Convergent evolution – adaptations in species from different evolutionary branches may come to resemble one another if they have similar ecological roles and natural selection has shaped analogous adaptations

Analogy – similarity of structure between two unrelated species, attributed to convergent evolution

The more removed two structures are the less likely it is they evolved independently (example-skills of the chimp can be compared to human skills)

III.Classify organisms

Fossil Record

Similar characteristics

Homology (likeness related to shared ancestry)

Analogy – similarity due to convergent evolution

Molecular biology compares macromolecules as well as anatomical features

a)Protein comparisons of amino acid sequences of two species

b)DNA, RNAcomparisons of genes or genomes of two species

1. Restriction mapping – uses restriction enzymes to cut a sequence of DNA into fragments, electrophoresis separates the sequences based on their length. Two samples of DNA can be compared for similarity in the locations of restriction sites.
2. DNA sequence analysis compares the actual nucleotide sequences of DNA segments between two species.

c)DNA Hybridization - Identifying and comparing homologous DNA sequences in two species using DNA sequencing. Measures the degree of homology between 2 single strands of DNA obtained from different sources

d)Molecular clock – rate of evolution seems to be constant over time. Analysis of mutation rate in proteins and nucleic acids suggests time of divergence from a common ancestor.

Competency 015

Taxonomy – the identification and classification of species, the study that arranges organisms in categories that reflect phylogeny.

Binomialnomenclature – two-part name assigned to each species, the scientific name of a species consisting of the genus and the species.

Genus – The first word of the binomial name to which the species belongs. Capitalized

Species – The second word of the binomial refers to one species within the genus.The species is expressed in lower case. The grouping “species” refers to a specific kind of organism. All members of a species possess similar anatomical structures and are able to interbreed.

Taxonomy classification:

a)Species – groups of a specific kind of organism

b)Genus – groups of related species

c)Family – groups related genera

d)Orders – groupsrelated families

e)Classes – groups related orders

f)Phyla – groupsrelated classes

g)Kingdoms – groups phyla

h)Domain – groups kingdoms

Taxon – The name of a taxonomic unit at any of the above levels.

Competency 0017

Organisms traditionally have been classified into a five kingdom system:

• Monera
• Protista
• Plantae
• Fungi
• Animalia

In the last decade, understanding of evolutionary history suggests to scientists an expanded classification system that places organisms into 3 domains, a taxonomic level above kingdom:

• Domain Bacteria

/ {Prokaryotes

• Domain Archea

• Domain Eukarya

/ {Eukaryotes

• Protista

• Plantae

• Fungi

• Animalia

Characteristicsof Archaeobacteria

1. Extreme environments

a. Salt water

b. Boiling hot springs

2. Differences between bacteria & eukarya

a. Molecular level and nucleic acids

3. In Archaea, absence of:

a. Nucleic envelope

b. Membrane-enclosed organelles

c. Peptidoglycan in cell wall

4.Present

a. Membrane lipids

b. RNA polymerase (several kinds)

c. Amino Acid – methionine

d. No coding (introns) parts of genes – (present in some genes)

e. Response to antibiotics – growth not inhibited (streptomycin & chloramphenicol)

Competency 0017

Viruses

a. Characteristics

1) Nucleic acid (DNA & RNA) enclosed protein coat capsid

2) Diverse in shape

3) Common structural motifs

4) No ribosome or equipment to make own protein

5) Limit host range – lock & key fit between surface proteins

Competency 0017

Monerans –prokaryotic organisms commonly called bacteria.

a.Characteristics:

1)Adaptable

2)Double-stranded circular DNA

3)Divideby binary fission – asexualreproduction

4)Rapid proliferation in favorable conditions.

Differences

1)Eukaryahave linear DNA; translates large amount protein

2)↓ protein than virus.

Competency 0017

Fungi are eukaryotes and most are multicellular. Absorptive nutrition enables fungi to live as decomposers and symbionts. (Except for Yeasts, which are unicellular.) The bodies of fungi are constructed of units called hyphae (ingulae, hypha). Hyphae are minute threads composed of tubular walls surrounding plasma membranes and cytoplasm. The cytoplasm contains the usual eukaryotic organelles. The hyphae form an interwoven mat called a mycelium -the “feeding” network of a fungus.

Hyphae

Plasma membranes

Cytoplasm

Eukaryotic organelles

Mycelium

Competency 0017

Protists are the earliest eukaryotic descendents of prokaryotes. Protists are the most diverse kingdom of all eukaryotes. Protists vary in structure and function more than any other group of organisms. Most of the approximately 60,000 known species are unicellular in structure, but there are some colonial and multicellular species. Because most protists are unicellular, they are justifiably considered to be the simplest eukaryotic organisms. At the cellular level, many protists are exceptionally complex – the most elaborate of all cells.

By itself a protist is an organism as complete as any whole plant or animal. Most are aerobic in their metabolism, using mitochondria for cellular respiration. Most are motile, having flagella or cilia at some time in their life cycles. They are found almost anywhere there is water.

Competency 0018

I. Non-vascular plants (algae, mosses e.g.)

A. Structural characteristics

1. Many grow in tight pack

2. Spongy quality

3. Able to absorb and retain water

4. Short and hug the earth

5. Elongated cells or filaments called rhizoids for the root system.

6. Stem like and leaf like appendages from the upper part

B. Life cycle-Alteration of generations

a. Haploid cell

b. Diploid cell

c. Zygote

C. Functions

a. Stabilizing atmospheric CO2

1) Climate stabilization

b. O2 production (algae)

c. Water movement

1. Imbibed like sponges

2. Diffused throughout plant

II.Vascular plants (Ferns, Angiosperms, Gymnosperms)

1. Ferns: The first Vascular Plants having a vascular system but lack true roots and true leaves
2. Xylem – tissue that carries water to all parts of the plant
3. Phloem – tissue that carries nutrients and products of photosynthesis to all parts of the plant
4. Seed Plants – Adaptations are roots, stems, leaves and seeds allow these plants to survive in land environments
5. Gymnosperms – cycads, gingkos, conifers
6. have naked seeds contained in cones
7. Angiosperms – flowering plants – reproduce sexually with flowers in a process called pollination
8. seeds are protected within a fruit

B. Life cycle of Seed Plants

Show alternation of generations. The sporophyte generation is the plant that is most visible. The gametophyte is very tiny, growing and maturing within the structure of the sporophyte called either a flower or a cone. This adaptation eliminates the need for standing water in the reproductive process.

Competency 0019

Characteristics, functions and adaptations of animals

1. Contrast and compare life cycles of vertebrates and invertebrates

Vertebrates – Backbone

Phylum: Chordata. Classes: Mammals, birds, reptiles, amphibians, fish /

Invertebrates – without a backbone

Phyla: Porifera (sponges); Cnidaria (hydra, jellyfish); Platyhelminthes (flatworms, flukes, tapeworms); Nematoda (roundworms); Mollusks (clams, snails); Annelids (earthworms); Arthropods (spiders, insects); Echinoderms (sea stars, sea urchins); Invertebrate Chordates (tunicate)

• Sexual reproduction
• Land based
• Larger size, active lifestyle
• ↑ fuel req, amniotic eggwas areproductive adaptation enabling survival on land
• amniotic egg develops in reproductive tract of female
• Neural crest, cephalization, vertebral column, closed circulatory system

/ Sexual and Asexual reproduction techniques.
Hermaphrodite forms in some species
Many are marine creatures
Increasing complexity through the phyla
Great diversity

2. Processes of Life: Order (organization – cell, tissue, organs, organ system), growth and development, energy utilization(feed, respire, internal transport, excretion), response to environment, homeostasis, movement, reproduction

3. Metabolic rates of animals– amount of energy it takes to maintain each gram of body weight is inversely related to body size, i.e., the smaller the animal the higher the metabolic rate.

Metabolism definition – the totality of an organism’s biochemistry

Harvest chemical energy from food ingested

Energy measured in calories or kcal

Competency 0026 – sub area I – Ecology

Population– individuals of a single species that simultaneously occupy the same geographic area, rely on the same resources, are influenced by similar environment and have an ↑ degree of interacting with others.

Density – the # of individuals per area.

Dispersion – The pattern of spacing among individuals.

Community – All organisms that inhabit a particular area or the different species that live close enough together to have potential interaction.

Factors affecting population size and growth rate

1. Birth rates, death rates

2. Exponential model of population growth describes an idealized population with unlimited resources(a theoretical construct because no environment has unlimited resources)

3. Logistic model of population growth describes the maximum population size (carrying capacity) that a particular environment with its finite resources can support with no net increase or decrease over a long period

Population growth curve:

COMPARISON OF TWO MODELS OF POPULATION GROWTH
Exponential Model / Logistic Model

• No limitation on population increase

/

• Considers ↑ and ↓ density

• No limit on resources

/

• Relative to the carrying capacity of the environment

• ↑ density = ↓ resources

Relationships among organisms with population density

• ↑ predation
• competition for limited resources
• stress relative to crowding
• build up of toxins

The result of any of above →↓ growth rate.

Competency 0027 – Key Terms

Ecosystem
Tropic structure
Tropic level
Primary producers
Primary consumers
Secondary consumers
Tertiary consumers
Detritivores
Detritus
Denitrification
Food chain
Food web
Production
Consumption
Decomposition
Primary productivity
Gross primary productivity / Productivity
Net primary productivity
Biomass
Standing crop biomass
Limiting nutrient
Secondary productivity
Biomass pyramid
Turnover time
Pyramid of numbers
Biogenochemical cycle
Nitrogen fixation
Ammonification
Long-term ecological research (LTER)
Biological magnification
*Greenhouse effect

Competency 0027

Ecosystems – major communitiesof organisms – all the organisms in a given area along with nonliving factors with which they interact: a biological community and its physical environment: i.e., rainforest terrarium

Biomes – a major type of ecosystem that covers a large geographic region and that is largely determined by climate, usually classified according to predominant vegetation, and characterized by organisms adapted to the particular environments.

Trophic level – a level in a food chain.

Trophic structure – the feeding relationship in an ecosystem. Trophic structure determines the route of energy flow and the pattern of chemical cycling in an ecosystem.

Herbivores – organism that eats plants.

Consumer – organism that eats other organisms.

Producers – organism that uses the energy from sunlight to make organic food molecules from CO2;and H20 and other inorganic raw materials, i.e, a plant, algae or autotrophic bacteria.

Autotrophs – organism that makes its own food, sustains itself without eating other organisms or their molecules. Plants, algae and photosynthetic bacteria are examples. An autotroph is a producer organism.

Heterotrophs – organism that can’t make its own organic food molecules and must obtain them by consuming other organisms or their organic products, i.e., a consumer or a decomposer in a food chain.