MidTerm Exam #1 Flashcards
What is this courses main question?
What does it mean to be human?
How do we study the question: What does it mean to be human?
Anthropology
Anthropology
The study of humans
What are the 4 subsidies of anthropology?
- linguistic anthropology
- Social anthropology
- Archaeology
- Biological anthropology
What area of anthropology are we focusing on in this course?
Paleoanthropology
Where do humans fall on the tree of life?
- animals
- mammals
- primates
- apes
- HOMO SAPIENS
Bipedalism
locomotion on two feet
facultative bipedalism
temporary locomotion on two feet in specific situations
habitual bipedalism
primarily bipedal, but is easily capable of other forms of locomotion
Obligate Bipedalism
exclusively bipedal, no practical alternative
Human complex langauge
- humans communicate in over 7,000 spoken languages
- all languages are transmitted through social learning
- all languages have complex grammar and syntax rules and infinite vocabulary
Dimorphism
a trait that occurs in distinct forms between members of the same species (Di=two, morph= shape)
Sexual Dimorphism
traits the occur between different genders within a species (male vs. female)
humans have reduced sexual dimorphism
How many teeth does the modern human have?
32 teeth (including canines, molars, premolars, and incisors)
Human Brain
human brains are larger than other mammals or primates, and grows way slower than other primates.
Precocial
born in an advanced state and able to feed itself and move independently almost immediately.
Altricial
born helpless and requiring significant parental care.
Material culture
human societies modify and engage with physical objects, tools, and resources
Humans are sweaty apes because:
humans have less body hair
humans have more sweat glands
Globally Distributed
Species encounter and adapt to diverse environments and use different sets of complex tools in each environment
Phenotype
an organism’s observable physical trait
Phenotypic Diversity
a change in phenotypes that arises from the interaction of environment and genetics
Phenotype examples
Skin, eye, and hair color
size and physical form
Evolution
change in heritable characteristics of biological populations over successive generations
evolution occurence
Occurs at the population level over time.
(traits can very between individuals but on populations evolve)
Evolution is Directional. T or F?
False!
Species change depends on their environmental context with no pre-determined direction. Evolution is NOT linear, progressive, or pre-determined.
Biocultural
Biological and Cultural
Humans are Biocultural. T or F
True
(our biology influences our culture and vice versa)
Stabilizing Selection
natural selection that occurs when average traits have more reproductive success. (medium/average beak size)
Directional Selection
natural selection that occurs when one extreme of a trait has more reproductive success. (either a bigger or smaller beak is better)
disruptive selection
natural selection when both extremes of a trait have more reproductive success. (both a larger and smaller beak are better than an average beak)
What is natural selection?
survival of the fittest
has 4 necessary conditions (overproduction, genetic variation, struggle to survive, and differential reproduction)
Overproduction
when a species has to many offspring then what can survive to maturity, which creates competition for limited resources.
Genetic Variation
there is a variation of a trait between individuals within a population and this trait has to be able to be passed down to offspring
Struggle to Survive
Conditions where the variating trait is used and becomes helpful and key to surviving in that environment and obtaining limited resources
Differential reproduction
Success of a differentiated trait being passed down to the next generation in a population through reproduction.
Evolutionary fitness
Having the ability to pass down genetic traits through reproductive success to your offspring
Reproductive Success
an individuals ability to have offspring that can survive and then have their own offspring
Where is DNA found in the cell?
The Nucleus
Where is DNA found in the eukaryotic cell?
Mitochondria: Mitochondrial DNA
Nucleus: Nuclear DNA
Are humans eukaryotes?
Yes!
almost all of our cells have two kinds of DNA
Chromosomes
discrete structures containing nuclear DNA; has 23 pairs in humans
Homologous Chromosomes
Chromosomes that carry information for the same traits; 1 from father and 1 from mother
Diploid #
full complement of chromosomes; found is somatic cells
Haploid #
half set of chromosomes; found in gametes
Somatic Cell
the cells that make up humans bodily tissues other than the reproductive tissues (ex: heart, skin or brain); each diploid somatic cell carries two copies of your genome
Gametic cell
the human bodies reproductive cells; includes sperm and eggs. Each haploid gametic cell carries one copy of your genome
What is the structure of DNA?
DNA molecules are made of two chains of nucleotides
Nucleotide
phosphate, sugar and a base
Base
adenine (A), thymine (T), cytosine (C), and guanine (G)
A + T and C + G
Structure of DNA
- nucleotides link into chains to form a single strand of DNA
- Phosphate-sugar “backbone” provides structure for the molecule
- Bases (A,T,C,G) are the units of genetic information
What’s the cause of the twisting shape in DNA?
the electro-chemical properties
Gene
A specific segment of DNA, made up of a sequence of nucleotide base pairs
Allele
a specific version or variant of a gene (ex: ice cream being a gene, different flavors would be alleles).
Steps to DNA replication
- the double strands “unzip”
- nucleotides attach to the free bases
- original strands separate completely, each component strand then has a new complimentary strand
- enzymes “proofread” the new strands
whats the error rate of DNA replication?
the error rate is about 1 mistake per billion base pairs (human genome has about 3 billion base pairs)
Mitosis
the process of cell division for somatic cells, which then results in two identical daughter cells.
Diploid retention is retained (full component of chromosomes).
Meiosis
the process of cell division for gamete production, sex cells only require half the number of chromosomes. This process results in four daughter cells.
Gametes are Haploid
The role of gender in Meiosis
Only one chromosome from each parent is passed onto the offspring. For males the result of 4 daughter cells are all continued on to become sperm. But for females only one of the four continues to become an ovum.
Variation in DNA replication
happens when homologous chromosomes crossover and exchange genetic information during meiosis, which creates new combinations of genetic variation to pass onto the next generation
Mutations
errors that happens during the process of DNA replication. Most, but not all, are neutral (aka have no effect on physical traits).
When can mutations be passed down to offspring?
Mutations can be passed down during Meiosis cell division, during the production of gametes.
What’s the primary source of Alleles?
Mutation
Polymorphic
A genetic site where more than one allele can occur
Protein Synthesis
the process where cells create proteins, which all cells need to function. (ex: hormones, enzymes, antibodies, and structures)
Hormones
A protein that acts like a messenger to the body to regulate various physiological processes and behaviors.
Enzymes
A substances produced by a living organism that has the job of speeding up reactions and facilitating the process of DNA replication.
Antibodies
a blood protein produced to counteract specific antigens, such as bacteria or foreign substances in your blood.
Structures
protein that makes up a living organism on multiple levels such as muscles, hair, ligaments, fingernails, eyes, and organs.
What are the two steps to protein synthesis?
Transcription and Translation
Transcription
The first step to protein synthesis, which involves synthesis of messenger RNA (mRNA) from a DNA template.
Translation
The second step to protein synthesis, which involves synthesis of an amino acid sequence (protein) from the mRNA template.
Key to remembering protein synthesis
DNA»>RNA»>protein
DNA versus RNA
DNA:
double stranded
has Thymine (T)
A=T
RNA:
Single Stranded
has Uracil (U)
A=U
Transcription
synthesis of messenger RNA (mRNA) from a DNA template
DNA transcription steps (takes place in the nucleus)
- DNA molecule denatures
- mRNA molecule is built by adding free-floating RNA molecules to the DNA strand
- mRNA strand then breaks away and DNA zips back up
Gene
the DNA sequence that influences a trait by coding for a protein. (for transcription to occur the gene must be turned “on” or expressed)
Splicing
the process in which only the exons end up in the mRNA strand
exon
the coding segment found within the Gene
introns
the non-coding DNA segment that is found within the Gene
Translation
synthesis of amino acid sequence (protein) from the mRNA template
What changes during DNA translation?
-mRNA is read by the ribosome (in triplets, called codons)
-Amino acids chained together to form proteins
What is the two main functions of DNA?
- Replication
- Protein Synthesis
What are the sources of genetic variation?
- Mutation = new alleles
- Recombination = new combinations of alleles
Gregor Mendel
Discovered the principles of inheritance by breeding pea plants. By observing the physical traits of pea plants, he figured out the relationship between genotype and phenotype.
Mendelian Genetics
most of the traits Mendel observed in the pea plants were monogenic.
Monogenic Traits
controlled by a single gene
(in monogenic traits, different phenotypes can be produced depending on which two alleles an organism possesses)
What are the two types of diploid organisms?
Homozygous and Heterozygous
Homozygous
having the same allele at the same genetic locus (BB or bb)
Heterozygous
Having two different alleles at the same genetic locus (Bb)
Dominant Allele
Only one copy of the allele is needed to be expressed in the phenotype
Recessive Allele
Two copies of the allele are needed to be expressed in the phenotype
Punnett Square
A diagram used to visually demonstrate the allele combinations for monogenic traits in offspring from two parents.
How many Genes does a human have?
Approximately 22,333
How are monogenic traits controlled?
By one singular Gene
How are polygenic traits controlled?
By mutliple Genes
Pleiotropic traits
several traits controlled by a single gene
Non-Coding DNA
- only 2% of the human genome contains protein coding genes
- the rest is non-coding DNA which does not produce proteins
- a lot of non-coding DNA is involved in gene regulation
Mechanism of evolution
- mutation
- gene flow
- genetic drift
- natural selection
Mutation
Any alteration in the genetic material or processes.
In evolution we are primarily concerned with those mutations that affect the germline (gametes)
Gene Flow
movement of genetic meterial from one population to another
can occur due to migration between populations
