Sampling methods Daphnia Random samples with a smaller collection beaker 50 ml Since the volume sampled is smaller than the container several samples.

Sampling methods

Daphnia

Random samples with a smaller collection beaker 50 ml

Since the volume sampled is smaller than the container several samples should be taken and then averaged

Sample 1 : 1 daphnia

Sample 2 : 5 daphnia

Sample 1 : 1 daphnia

Sampling Daphnia

Sample 1 : 1 daphnia

Sample 2 : 5 daphnia

Sample 1 : 1 daphnia

7/5 = 2.3 daphnia / 50ml

=.045 daphnia / ml

Total volume = 4000 + 500ml

.045 daphnia / ml * 4500 ml = 210 daphnia

Scientific Revolution

Genetic Engineering refers to the process of moving genes from one organism to another. Having major impact on medicine

and agriculture.

Sampling Hydra

Random grids:

select three grids

count the number of hyra

Hydra/ grid

1

0

0

.33 hydra /grid

30 grids cover the container.

.33 hydra/grid * 30 = 10 hydra

Recombinant DNA is DNA taken from two different sources and fused into a single DNA molecule. Special DNA cutting enzymes, called restriction enzymes, cut the DNA at specific sites.

Recombinant DNA technology has extensive applications in developing pharmaceuticals.

The first drug created using recombinant DNA was human insulin.

Piggyback Vaccine

Transgenic Golden Rice

Other Genetic Techniques Polymerase Chain Reaction (PCR)

Other Genetic Techniques DNA

Fingerprinting

Need a restriction enzyme that will cleave known segments of DNA

Restriction enzymes specific for organism

DNA fragment migration through the gel dependent upon fragment size

Bands do not represent genes

Genomic Time Line

First free-living organism was the bacterium Haemophilus influenzae sequenced in 1995. 1,830,137 base pairs

First eukaryotic genome was baker’s yeast Saccharomyces cerevisiae. 13,000,000 base pairs

First animal was nematode C. elegans (1998). 100,000,000 base pairs

Human Genome Project

1990 American geneticists embarked on attempt to map and sequence entire human genome (3.2 billion base pairs). DNA fragment of unknown sequence

is amplified, mixed with a primer and supply of bases, and four different chain-terminating tags. After heated, mixture will contain series

of fragments of different lengths.

Human Genome Project Fragments separated according

to size by gel electrophoresis. Radioactively labeled and visualized

on x-ray film, and sequences read by humans, or automated systems.

Genomic Strategies Original plan for Human Genome Project

was systematic and conservative using detailed maps of each chromosome and then cloning fragments into bacterial plasmids.

May 1998, Craig Venter proposed shotgun sequencing which skipped the mapping step and chopped the entire human genome. Both research groups finished in June 2000.

Human Genome Characteristics

Geography30,0000-40,000 genes

Fragmented into exons and introns.

Not distributed evenly over the genome.

Chromosome size is not a clear indication of number of genes.

Proteomics

Bioinformatics Utilizing molecular genetics and

powerful computational analysis to predict what sort of protein a particular sequence encodes.

Proteomics Cataloging and analyzing every

protein in the human body. Protein arrays are being developed to

study all an organism’s proteins.

Origin of Life•Three possibilities for the appearance

of first living organisms on earth:– Extraterrestrial origin– Special creation– Evolution

•All life is composed of the organic macromolecules: carbohydrates, proteins, Lipids and nucleic acids.

Origin of life•Scientists suspect first macromolecules

were RNA molecules.•First cells may have aggregated

spontaneously.• Miller and Urey

experiment• Early earth conditions

– No oxygen

– SH2 gas

– NH3

– CH4

• fossil evidence refutes findings

• Environment was not conducive to life originating from the primordial liquid

No ozone may have not been present in high enough amounts

– Bubble model proposes key chemical processes generating the building blocks of life took place within bubbles on ocean’s surface.

•Before 1.7 billion years ago, only prokaryotes found in fossil record.– First microfossils (eukaryotes) appear

in fossil record 1.7 billion years ago.

How Cells Arose•Endosymbiotic Theory

– Energy-producing bacteria formed symbiotic relationship with early eukaryotic cells. Eventually evolved into mitochondria.

Pelomyxa palustris

Evolution of PlantsChapter 16

Outline

•Adapting to Terrestrial Life•Vascular Plants•Seedless Vascular Plants •Seed Plants

– Gymnosperms– Angiosperms

•Flowers– Dicots and Monocots– Seed Dispersal

Stromatolites(fossilized algae and phytoplanton

Adapting to Terrestrial Living

• Green algae that were probably the ancestors of today’s plants are aquatic organisms not well-adapted to living on land.– Had to overcome three challenges:

• Minerals absorption from rocky surfaces• Water conservation• Reproduction on land

Adapting to Terrestrial Living

Adapting to Terrestrial Living

•Mineral Absorption – symbiotic fungi– Plants require relatively large

amounts of six inorganic minerals:•Nitrogen, potassium, calcium,

phosphorus, magnesium, and sulfur.– Mycorrhizae

Adapting to Terrestrial Living

•Water Conservation– Cuticle - watertight outer covering.

•Stomata - gas and vapor exchange.

Adapting to Terrestrial Living

•Reproduction on Land– Due to immobility, gametes must

avoid drying while they are transferred by wind or insects.•Spore Development

– Generation alteration•Sporophytes - diploid generation•Gametophyte - hapolid generation

Evolution of Vascular System

•Terrestrial plants are required to carry water up from roots to leaves, and carbohydrates down from leaves to roots.– Vascular System

•Specialized strands of connected hollow cells.

– Nine of Twelve living plant phyla are vascular.

Nonvascular Plants

•Only two phyla of living plants lack a vascular system:– Liverworts (Hepaticophyta)– Hornworts (Anthocerophyta)

•Simple Vascular Systems– Mosses were first plants to evolve

strands of specialized conduction cells.•No specialized wall thickening.

Evolution of Vascular Tissue

• Appeared approximately 430 mya.– Grew by cell division at the tips of

stem and roots (Primary Growth).

• About 380 mya vascular plants developed a growth in which a cylinder of cells beneath the bark divides, producing new cells around plant’s periphery (Secondary Growth).– Necessary for tall trees with thick

trunks.

Leaf Vascular System

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Vascular tissue

Xylem – water transport Phloem – food transport

Vascular tissue – secondary growth

Seedless Vascular Plants

• Most abundant of the four phyla of seedless vascular plants contain ferns with about 12,000 living species.– Have both gametophyte and

sporophyte individuals, each independent and self-sufficient.•Gametophyte produces eggs and sperm.•Sporophyte bears and releases hapolid

spores.

Seed Plants

• Seed - Embryo cover that offers protection of embryonic plant at its most vulnerable stage.– Male and Female gametophytes

• Male - microgametophytes (pollen grains) arise from microspores.

• Female - megametophytes contain eggs and develop from megaspores produced within ovule.

– Pollination - transfer of pollen.