gregor mendel bred pea plants and observed their characteristics such as shape, color, etc

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!!!