Anthropology EXAM 2

Gregor Mendel

Gregor Mendel

Father of genetics. Worked with a variety of pea plants. He looked at texture, color,, etc. Goal was to understand how traits are passed on.

Particular Inheritance

Each trait is determined by a pair of discrete particles (alleles).

Laws of segregation

Allele pairs segregate from one another. Each pair is inherited at random.

Independent assortment

Alleles for different genes are inherited independently of one another.

Genes

A stretch of DNA that produces a protein product. Only functional segment of DNA that is transcribed.

Alleles

The particular DNA sequence in that segment of the genome.

Genotype (Homozygous)

When a person has two identical versions of a gene, one from each parent.

Genotype (Heterozygous)

When an organism has two different versions of the same gene.

Phenotype

A set of observable characteristics of an individual resulting from the interaction of its genotype with the environment.

Dominance

Expressed even in the presence of different allele. Ex: Brachydactyly

Recessiveness

Expressed only when an individual has two copies of the same allele. Ex: Albinism

Chromosomes (autosome)

Are not sex chromosomes. There are 22 autosomes and are paired with sex chromosomes. They look the same in both genders.

Chromosomes (sex chromosome)

Carry genes that determine an individuals sex.

Haploid

A single set of chromosomes in an organism’s cells.

Diploid Cells

Receive half of their chromosomes from their father, and half from their mother.

Meiosis

special type of cell division that produces gametes (sperm and egg cells)

Fertilization

The process of a sperm and egg uniting to create a zygote (diploid cell).

Crossing over

Cellular process that occurs during meiosis when chromosomes of the same type line up.

Recombination

The process of exchanging genetic material between organisms, which results in offspring with different trait combinations than either parents.

Brachydactyly

Genetic condition that causes fingers and toes to be shorter than normal relative to the length of other parts of the body.

Pedigrees

A diagram that shows how a trait or health condition is passed down through generations within a family.

Folk Heredity

Cultural ideas about heredity, not entirely scientific. Scientists believed that undesirable behaviors and acts were connected to a recessive allele. They connected this to people in poverty.

Henry Goddard (The Kallikak Family)

Believed that people inherit feeble-mindedness and should reproduce accordingly.

Eugenics (Positive)

Encourage reproduction another the genetically advantaged. So, wanted the reproduction of the healthy, the intelligent, and the successful.

Eugenics (Negative)

Suppressed reproduction among people that were considered inferior.

Charles Davenport

Founded the eugenics record office and the American eugenics society. Promoted sterilization and wanted to prevent those who were deemed unfit to produce.

Madison Grant (Passing of the Great Race)

Published a book called “The passing of the great race. Also drew connections between the ideas of eugenic and race.

Buck v. Bell

Carrie and Emma Buck were sterilized without their knowledge. Despite both being deemed feeble-minded, they went on to be in good standing academically.

DNA (deoxyribonucleic acid)

Made up of letter strings. Has 3.2 billion nucleotides. It is how traits are passed along from parents to offspring, which depends on the DNA structure

DNA Replication

Allows DNA to be duplicated easily. Anytime there is a new cell being created in the body DNA replicating is occurring. This is a process that take advantage of the DNA

DNA polymorphisms (another way of saying genetic variation)

• Single nucleotide substitution: single letter change in the DNA sequence.

  Ex: TCGCATA → TCGTATA

• Indel: Extra nucleotide (insertion or deletion)

  Ex: TCACATA → TCGCTATA

  TCGCATA → TCGCTA

• Duplication: a cell copies its DNA before dividing.

  Ex: TCGCATA → TCGCACATA

• Inversion: something gets cut out flipped 180 degrees and then put back (put back backward0

  Ex: TCACATA → TCFTACA

• Translocation: a chunk of chromosomes gets removed, and then

  attached to a new place.

• Microsatellite: a string of DNA from 1-6 letters that will be repeated over again

Human genome

Depending on the male’s age depends on how many genes from the father were given to the children. Includes both nuclear and mtDNA.

Transcription

Creates single stranded RNA based on the double stands DNA.

RNA

• single stranded

• contains ribose sugar

RNA Processing

mRNA modification.

• Cap

• tail

• splice

Exon vs. Intron

Exon: the nucleotide sequence you keep.

Intron: the nucleotide you don’t need, so they get cut out.

Translation

Cell proteins using the genetic information carried in messenger RNA (mRNA)

Codons

A sequence of three DNA or RNA nucleotides that corresponds to a specific amino acids or stop signal during protein synthesis.

The genetic Code

A set of rules that living cells use to translate genetic material into proteins.

Amino acids

An organic compounds that contain both amino and carboxylic acid functional groups.

Proteins

Molecules made up of amino acids.

This includes:

• Structural

• Transport

• Enzyme

• Nutrient

• Defense

• Regulatory

Pleiotropy

One gene influences multiple traits.

Polygenic traits

A trait influenced by multiple genes.

Regulation of gene expression

A set of mechanisms that cells use to increase or decrease the production of specific gene products.

Sickle cell trait

A genetic trait caused by a single genetic strand. It is assumed that this is a disease connected solely to black people. This isn’t true.

Thalassemia (Alpha)

Deficiency in production of alpha global chain.

Thalassemia (Major)

Reduced production of beta globes chain.

Hox genes

Influenced by early embryo development. Plays a part in determining what each part of the embryo gets developed. Ex: the head, neck, etc.

Human variation in height

There’s a connection between height and environment. People who live in colder climates are shorter than people who live in hotter climates.

Cormic index

Sitting height ÷  Standing height

Human variation in weight/ body mass

Body weight is also connected with climate. People usually have more body mass in colder climates than people who live hotter climates. Metabolic heat production is proportional to body weight/volume.

Bergmann’s rule

Organisms living in colder climates have larger, heavier bodies (total body mass is greater).

Allen’s rules

Appendage length is shorter in colder climates and longer in warmer climates.

Skin function:

• Dermis: Inner layer of the two main layers of the skin.

• Epidermis: Outside layer and made up of cells called keratinocytes.

• Keratinocytes: Produce keratin, which is a tough, protective protein.

• Melanocytes: Produces and contains the pigment called melanin.

Epigenetic (DNA methylation)

A type of epigenetic modification that regulates gene expression.

Hardy-Weinberg equilibrium model

Describes a relationship between allele and genotype frequencies in a non-evolving population.

Mutation

Random change in the DNA sequence which can cause certain traits to become present, usually occurs from a transcription error.

Genetic essentialism

The belief that genes are linked to certain behaviors, conditions, or social groups.

Alternative splicing

Generates several proteins from one gene.

Population genetics

The genetic composition of a population and how its allele frequencies change over time and across space.

Non-random mating

Assortative mating, which is mating influenced by a phenotype with a genetic basis.

Mitochondrial DNA (mtDNA)

Generates energy/powers the cells. mtDNA is passed down from the mother.

Gene Flow

The transfer of genes from one population to another.

Monogenic

Traits that stem from a single gene.

Antigens

Proteins recognized by the immune system and capable of stimulating production of antibodies.

Antibodies

Proteins in the blood serum that react to foreign antigens and protect the body by binding to those antigens.

Karl Landsteiner

Conducted experiments with blood to explain why some blood samples clumped and others would not when reacting with each other, responsible for the ABO blood group system.

ABO blood group

A and B are dominant alleles, O is a recessive allele.

ABO blood types and selection

AA, AO, BB, BO,AB,OO

Duffy blood group

• Three co-dominant alleles: Fy^a, Fy^b, Fy^c (Fy^4)

• Alleles coding for specific antigens on the red blood cells.

• Allele frequencies reflects selection for resistance to malaria caused by plasmodium

  vivax

Hemoglobin

A protein in Red blood cells that carries oxygen. Has an alpha globin and beta globin.

Melanin

• Plays a roles in absorbing and scattering uv radiation

• Prevent radiation from getting deeper into the body due to it being the things that can

  destroy DNA

• Two types of melanin: eumelanin and pheomelanin

Skin color

• Constitutive skin color: genetically-determined melanin pigmentation produced without any influence of solar radiation.

• facultative skin color: short lived tanning that result from exposure to UV radiation

Genetic basis of skin color

• The color of your skin has no influence on how many melanocytes you have. It depends on how much melanin one has.

• Darker skin = equal distribution of melanin (more melanin)

• Lighter skin = less melanin

Evolutionary hypotheses for skin color variation

Melanin pigmentation evolved to regulate UV exposure

Erythroblastosis fetalis

a rare pregnancy complication that occurs when the mother’s antibodies destroy the fetus’s red blood cells.

Molecular mimicry

One of the leading mechanisms by which infectious or chemical agents may include autoimmunity. It occurs when similarities between foreign and self-peptides favor an activation of autoreactive T or B cells by a foreign-derived antigen in a susceptible individual.

Blood

• Erythrocytes: Red blood cells

• Leukocytes: White blood cells

• Serum: Fatty acids

Phylogeny

Diagram showing the common ancestors of a set of DNA sequences.

Deme

The breeding population; group of interacting individuals who can potentially mate and interbreed

Agglutination

The clumping of cells due to antibodies binding to antigens.

Genetic drift (bottleneck, founder effect)

Refers to genes randomly changing in frequency all by chance. Genotypes may disappear entirely.

Rhesus Blood group system

• Two phenotypes: RH+ and RH-

• If you have Rh+, you have RH antibodies, but no RH antigens are attached to the blood cells.

• If you have RH-, you have no RH antibodies, but has the RH antigens on the red blood cells