Human Bio- Unit 3

MRSA

Methicillin Resistant Staphylococcus aureus

Normal Flora

Bacteria living on/in humans

Colonized

If you carry a bacterium, but you aren’t sick, you are…

Virulent

Description of staph strands that cause sever damage

Drug-resistant bacteria

It can emerge immediately after the antibiotic is developed

Beta-Lactam

Antibiotics that interfere with the bacteria’s ability to synthesize a cell wall

W/o beta lactam antibiotics

Water flows into the cell (osmosis) and creates hydrostatic pressure, but the wall stays intact

W/ beta-lactam antibiotics

Water flows into the cell (osmosis) and creates hydro static pressure, rupturing the weakened cell wall, killing the cell

Binary fission

An asexual way of reproduction that bacteria uses to create daughter cells

Population

A group of individuals in the same species living together in the same area

Genetic variation

The genetic differences between members of a population

Gene transfer

When pieces of DNA pass between bacteria

Evolution

A change in the frequency of alleles in a population over time

fitness

an organisms ability to survive and reproduce in a particular environment

Natural selection

The higher survival and reproduction rate of individuals with a certain trait in a population

Directional selection

The environment favors an extreme phenotype

Stabilizing selection

the environment favors the middle of the phenotypic spectrum

Diversifying selection

the environment favors both ends of the phenotypic spectrum

Population genetics

The study of the genetic makeup of a population and how it changes over time

Gene pool

The total collection of alleles within a population

Allele frequency

the relative proportion of an allele within a population

Non-adaptive evolution

A random change in the allele frequencies of a population

Mutations

Random changes in the DNA of an individual

Genetic drift

Random change in allele frequencies in a population between generations

Mutations and Genetic drift

Mechanisms of non adaptive evolution

Founder effect

A small group of settlers split from the population and establish a new one (genetic drift)

Bottleneck effect

Occurs when the population is suddenly reduced to a small number of individuals (genetic drift)

Gene flow

The movement of alleles between populations as individuals leave and enter and breed with other populations

inbreeding

Mating between closely related members of a population

Biological species concept

A species who’s members can inbreed and produce fertile offspring

Reproductive isolation

Mechanisms that prevent certain species from mating

Ecological isolation

Species that live in a different environment (reproductive isolation)

Behavioral isolation

Species that have different mating activities (reproductive isolation)

Gametic isolation

Species that have incompatible gametes (reproductive isolation)

Temporal isolation

Different mating/fertility time frames (reproductive isolation)

Mechanical isolation

incompatible mating organs (reproductive isolation)

Hybrid inviability

Species gametes unite, but the zygote doesn’t survive (reproductive isolation)

Hybrid infertility

Offspring are viable but not fertile (reproductive isolation)

Speciation

New species developing due to the prevention of gene flow and the separation of populations

The Theory of Evolution

What Darwin called descent w/ modification

Evidence of Evolution

Primordial soup, fossil record, homology, biogeography

Fossil Record

fossils arranged by age, showing change over generations

Vertebrate forelimb homology

The #, order, and structure of forelimbs are all similar in vertebrates

Homology

Showing a common ancestor

Embryological homology

Early embryos of vertebrate animals all look similar

Vestigial structure

Structures that show no function

Molecular homology

All living organisms share DNA/genetic code, however the sequence differs between species

Biogeography

The study of the natural geographic distribution of species

Pangea

The one landmass before the continents formed

Taxonomy

The organization of classifying organisms

Taxonomy categories

Domain, supergroup, kingdom, phylum, class, order, family, genus, species

Phylogeny

The evolutionary history of a group of organisms

Phylogenic tree

represents phylogeny

70,000

how long ago did humans start migrating

Melanin, folate, vitamin D

Components of skin color

Genetic

What decides skin color?

Melanocytes

Cells that produce melanin

Melanin

The pigment in skin and hair

Folate (folic acid)

We need it for basic cellular functions

Not enough vitamin D

What causes bone distortion?

Mitochondrial eve

The common ancestor of all modern humans, found in Africa

Hominid

Any living/extinct primate belonging to the hominidae family

Bipedalism

Ability to walk upright on 2 legs w/ free arms (human characteristic)

Large Brain

Provides the ability for complex language and problem solving (human characteristics)

Positive Selection

The mutation has greater reproductive success in the environment

Negative Selection

The mutation as less reproductive success int he environment

Neutral selection

The mutation does not influence reproductive success in the environment