Post on 19-Dec-2015
TOPIC 7: Genetics
Gregor Mendel bred pea plants and observed their characteristics such as shape, color, etc.
Sexual vs. Asexual Reproduction
To go through Sexual reproduction, organisms need to use meiosis to create sex cells
Asexual Reproduction-not combining genetic material from two different sexes, usually creating exact copy
Genetics VOCABULARY Fertilization – joining male & female
reproductive cells Self pollination – pollen from one plant
fertilizes egg cell from the same plant Pure breed (true-breeding) – if self
pollination produces offspring identical to the parent
Cross pollination – pollen from one plant fertilizes egg of another plant
Heredity – how traits get passed from one generation to the next
GENETICS – scientific study of heredity P generation – parent generation
F1 – first filial – offspring of the P generation F2 – second filial – offspring of the F1
Dominant – allele shows up alone
Recessive – hidden allele unless there are 2
Genotype – genetic makeup (alleles)
Phenotype – physical appearance
Homozygous – 2 same alleles
Heterozygous – 2 different alleles
Y=yellow
yy=green
YY or yy or Yy
Yellow or green
yy or YY
Yy
How to Punnett
Non Mendelian Patterns of Inheritance
Some alleles are neither dominant nor recessive but are controlled by other factors
Such as Incomplete dominance Codominance Multiple alleles
Incomplete Dominance
One allele is not dominant over the other, instead the heterozygous genotype shows an intermediate phenotype
Types of Inheritance Incomplete Dominance
Traits are not dominant or recessive. The traits “blend” together to make a new color/trait.
Codominance
In the heterozygous genotype, both alleles are seen
Codominance
Black Feathered Chicken
White feathered chicken
Checkered feather chicken
Multiple Alleles
Some genes have more than 2 possible alleles
The INDIVIDUAL only carries 2 alleles though
Polygenic Traits A trait controlled by 2 or more genes with
a wide variety of phenotypes
Types of Inheritance Sex-linked
The trait is carried on the sex –chromosome (x-chromosome) so the inheritance is different for males and females.
Males inherit one gene from mother on X
chromosome and an unaffected Y from
father.
Females inherit an X from their father and
an X from their mother.
Genetics of Hemophilia
H=normalh= hemophilia
Sex linked=only on X chromosome
More common in males? Females?
What are the genotypes of each person?
TOPIC 8: Evolution
Process of change in a species over time
Charles Darwin – theory of evolution by natural selection Populations change in
response to environmental pressures and they become adapted to new conditions and they change over time.
Natural Selection
Allelic Frequency=Bell Curve
Adaptation – any heritable characteristic that increases an organism’s ability to survive and reproduce (it’s advantageous)
New adaptations come from mutations
Microorganisms under stress have more mutations and therefore evolve
What is a speices?
Morphological Species Concept Biological Species Concept
Speciation
Convergent Evolution
Divergent Evolution
Artificial Selection
Coevolution
Isolating Mechanisms
Separating 2 populations further and further until they can no longer interbreed to produce fertile offspring
Therefore going through speciation and forming a new species.
Geographic Isolation
Physical boundary
Reproductive Isolation
Occurs (one way) because species mate at different times
Behavioral Isolation
Differences in behavior, courtship, coloring, morphology, etc.
In the case pictured, the species became isolated by the food they became accustomed to eating.
Reproductive Isolation
Founder Effect/Bottleneck
Evidence for Evolution
Fossils Biogeography Homologous structures Analogous structures Vestigial structures Embryology Genetics and molecular biology
Fossils Record shows that species have gradually
changed over time
Biogeography
Distribution of life forms over a geographical area
Similar species share a common time & place
Homologous structures
Inherited and shared by related species
Analogous Structures
Body parts that share a common function but NOT a common structure
Vestigial Structures
Inherited from ancestors but have lost all or most of their original function
Embryology Similar
patterns of embryological development
Genetics and Molecular Biology
Genes nearly identical in almost all organisms
Similarities in Amino Acid Sequences
TOPIC 9: ECOLOGY Ecology – study of
how organisms interact with each other and their environments
Ecosystem Factors
BIOTIC – living or used to be living
Ex: bear, oak tree, bacteria, dead leaf
ABIOTIC – never been living
Ex.: sun, wind, rocks, water
Food Web
Heterotrophs – consumers of energy
Primary, secondary, tertiary, quaternary
Autotrophs – producers of energy
Photosynthesis or chemosynthesis
Food Web
Depicts the flow of energy through an ecosystem
Where do the decomposers belong?
Detritivores & Decomposers
Detritivore Consume non-
living organic matter, such as leaf litter, waste products, dead bodies
AKA scavengers Examples:
millipedes, condors
Decomposer Breaks down non-
living matter into simpler parts that can be reused.
Examples: bacteria, fungi
Energy in an Ecosystem Trophic level – feeding level of an
organism Amount of available energy decreases as
you move up in trophic level (10% Rule)
The Water Cycle
The Carbon Cycle
Nitrogen Cycle
If you recall the nitrogen cycle, only bacteria can convert nitrogen gas to a useable form, conversely, they are also the only organisms that can return it to the atmosphere.
Too much Nitrogen=Algal Blooms
An increase in the algae population in a body of water is referred to as an algal bloom.
This is not good for the other organisms living in that type of ecosystem. The water is difficult to see through, and the algae use all the dissolved oxygen so fish can no longer breath
Community Interactions
habitat = food, water, space, shelter, required for an organism to live
Niche = how organisms use its habitat to survive and reproduce
Resources = necessity of life; water, nutrients, light, food, space
Limiting factor = any chemical or physical factor that limit the existence, growth, abundance or distribution of an individual or population
Competition
Organisms of the same of different species attempt to use the same resource in the same place at the same time
Predation (+/-)
Interaction in which one organism captures and feeds (predator) on another (prey)
Symbiosis
Relationship in which 2 organisms live closely together
Parasitism (+/-)
One organism (parasite) relies on another (host) for nourishment or other benefit
Mutualism (+/+)
2 or more species benefit
Blind pistol shrimp dig burrows for goby fish who keep watch over them
Commensalism (+/0) Relationship where one species benefits
and another is unaffected
Endemic (Native) vs. Non native Species
Endemic Species found in its
originating location and is generally restricted to that geographical area
Non-Native Species Normally living
outside a distribution range that has been introduced through either deliberate or accidental human activity Can become
INVASIVE
The road to extinction…
Threatened – decrease in numbers could become endangered if no actions are taken
Endangered – population is dropping, may become extinct
Extinct – completely disappears from its area on the planet
Succession
A series of predictable and orderly changes within an ecosystem over time
The Greenhouse Effect=Good
Intensified Greenhouse Effect=
What can we do about Global Warming?
World Population Growth Patterns
Biological Magnification of DDT
Ozone “Hole” Over Antarctica CFCs
Alternatives to Pesticides
1.
2. Genetically engineer plants to taste bad to organisms
Can we sustain life on earth?
GOOD LUCK!!
Get a good night’s sleep! Eat a healthy breakfast (or a pop tart)
Read all directions and answer the question they ask!
Trust your instincts!!!