Transcript Sampling Daphnia

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.
Random grids:
Sampling Hydra
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
 Geography
 30,0000-40,000 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
• fossil evidence
refutes findings
• Environment was
– No oxygen
not conducive to
No ozone may have
– SH2 gas
life originating
not been present in
– NH3
from the
high enough amounts
– CH4
primordial liquid
– 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 Plants
Chapter 16
Outline
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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).
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
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.