Behavioral Neuroscience: Exam 1 Flashcards
Cartesian Dualism
The idea that the universe consists of two elements: physical matter and the human mind (soul, self or spirit). The mind and brain are viewed as separate entities.
Watson
A behaviorist who believed that all behavior was the product of learning (nurture).
Ethology
The study of animal behavior in the wold, focuses on intrinsic (nature) behaviors.
Evidence of Evolution
- Fossil evidence of evolution.
- Structural similarities among living species, suggesting common ancestors.
- Impact of selective breeding.
- Direct observation of evolution in progress (finches of the Galapagos Islands changed dramatically after one season of drought).
Evolution of Vertebrates
- Chordates have dorsal nerve cords***
- Vertebrates are chordates with spinal bones
Evolution of Amphibians
- Bony fishes leave the water briefly
- Advantages include fresh water and new food sources
Evolution of Reptiles
- Lay shell covered eggs, covered by dry scales
- Can live far from from water
Evolution of Mammals
- Develop mammary glands to nurture young
- Eventually no longer lay eggs, raise young in mother’s body
- Humans emerge from the order primates
Emergence of Humankind
- Humans belong to family Hominids, genus Homo
- First homo species emerged from Australopithecus 2 million years ago
- Homo sapiens emerged 200,000 years ago
Homologous Structures
Similar structures due to a common evolutionary origin.
Analogous Structures
Similar structures without a common origin (Ex: Birds and Bees, both developed wings from separate origins).
Convergent Evolution
The evolution of similar solutions to the same environmental demands by unrelated species.
Evolution of the Human Brain
- There is no relationship between brain size and intelligence
- Brain size is generally correlated with body size
- More informative to look at relative size of different brain regions
- The human brain has increased in size during evolution
- Most of the increase in size has occurred in the cerebrum
Gene
Genetic material, composed of DNA (Deoxyribonucleic acid).
Chromosome
Slender thread inside a cell’s nucleus that carries genes.
Genotype
Our genetic makeup.
Phenotype
Our observable traits.
Dominant Gene
Gene that masks other genes’ effects. When it is present it dominates.
Recessive Gene
Gene that is expressed only in the absence of a dominant gene.
Dichotomous Traits
A phenotypic (observable) trait that exists in one form, or another, but never in combination (Ex: eye color).
True-Breeding Lines
Interbred members always produce offspring with the same trait.
Mendel’s Experiment - Essay Question
Mendel had a true-breeding line of brown peas and a true-breeding line of white peas in his garden. He decided to plant one of his white pea plant seeds in the brown planter. When he returned he found that all of the offspring where brown. Once the brown offspring reproduce he found that 25% of the offspring have white seeds. Created the logical explanation for recessive and dominant genes.
Why does the first generation have no white seeds? Why does the second generation have white seeds?
Homozygous
2 identical alleles (BB, ww)
Heterozygous
2 different alleles (Bw)
Chromosomes
- Genes are located on chromosomes in the nucleus of each cell
- Humans have 23 pairs of chromosomes, with an allele on each chromosome
Meiosis
A process of cell division that yields cells with just 23 chromosomes (splitting). This is how you get separate egg and sperm cells - only cells in your body that only have 23 chromosomes, not 46.
Gametes
Egg cells and sperm cells.
Zygote
Fertilized egg cell that has 23 pairs of chromosomes.
Mitosis
A form of cell division that yields daughter cells that have 23 pairs of chromosomes (copying).
Epigenetics - Short Answer
Your genes and your environment are always interacting, your environment is constantly changing the expression of your genes. All of your phenotypic traits are the result of your genes being influenced by your environment.
Nucleotide-Bases - Short Answer
The four building blocks of life:
- Adenine - only connects to Thymine
- Thymine
- Guanine - only connects to cytosine
- Cytosine
DNA Replication
As the two strands of the original DNA molecule unwind, the necleotide-bases on each strand attach free-floating complementary bases. Once the unwinding is complete, two DNA molecules, each identical to the first, will have been created.
Sex Chromosomes
The 23rd pair of chromosomes. The first 22 pairs are called autosomal.
Female = XX Male = XY
Sex-Linked Traits
Influenced by genes on the sex chromosome. Dominant traits on the X chromosome will be seen more commonly in females, recessive ones in males.
Gene Expression - Essay Question
- Strand of DNA unravels around the specific gene.
- mRNA leaves nucleus and attaches to ribosome in the cell’s cytoplasm.
- Ribosome synthesizes protein according to 3-base sequences (codons) of mRNA (translation).
Regulation of Gene Expression
- Enhancers: Stretches of DNA that determine whether particular structural genes initiate the synthesis of proteins and at what rate.
- Transcription factors: Proteins that bind to DNA and influence the extent to which genes are expressed.
- Epigenetics: The pattern of actual gene expressions, vs. the genes possessed is most important.
Mitochondrial DNA
Mitochondria have their own DNA. Mitochondria are the energy-generating structures found in the cytoplasm of all cells. Mitochondrial DNA may be responsible for some disorders.
- Mitochondrial DNA never splits.
- The only way it changes is through mutation (only mutates through exposure to radiation).
Minnesota Twin Study
A study of twins reared apart showed that identical twins are more similar to each other than fraternal twins on all psychological dimensions. Identical twins have a higher correlation of IQ scores.
Multiplier Effect
Genetically similar individuals seek out similar environments.
Nervous System
A communication network consisting of nerve cells, both inside and outside of the brain and spinal chord. Consists of the central and peripheral nervous system.
Central Nervous System (CNS)
Consists of the brain and the spinal chord. Bony protective Armour.
Peripheral Nervous System (PNS)
Refers to all of the nerves that are located outside of the brain and the spinal chord. The PNS serves to bring information into the CNS and carry signals out of the CNS.
Somatic Nervous System
A subdivision of the peripheral nervous system. Controls the body and voluntary responses.
Autonomic Nervous System
A subdivision of the peripheral system. Controls involuntary and automatic responses.
Afferent Nerves
Brings information IN to the CNS.
Efferent Nerves
Brings information OUT of the CNS.
Sympathetic Nervous System
Part of the PNS and a subdivision of the autonomic nervous system. Causes you to startle, heart pace, sweat, fires rapidly in response to threats in the environment.
“Fight or Flight”
Parasympathetic Nervous System
Part of the PNS and a subdivision of the autonomic nervous system. Allows you to feel comfort.
“Rest and Relax”
Meninges
Layers of tissue between the brain and the skull - three layers.
Pia Mater
The first layer of the meninges located closest to the brain - this is the softest layer. Adheres to the CNS surface.
Arachnoid Membrane
The second and middle layer of the three meninges. This is a web-like layer that contains cerebrospinal fluid (CSF) and blood vessels.
Dura Mater
The third layer of the meninges located closest to the skull. This is the hardest layer - tough outer membrane.
Cerebrospinal Fluid (CSF)
Fluid that serves as a cushion. Also located inside the brain and circulates through all of the ventricles - useful for transporting sodium throughout the brain. CSF is made by the choroid plexus.
Blood-Brain Barrier
Tightly packed cells of blood vessel walls that prevent entry of many molecules and pathogens to the brain. However, oxygen, carbon dioxide and fats can pass through the barrier freely.
What is the chemical protection and the physical protection of the brain? - test question
The chemical protection of the brain is the blood brain barrier, and the three physical protections of the brain are the skull, meninges and cerebrospinal fluid (CSF).
Neuron
Specialized cells that receive and transmit electrochemical signals - come in many shapes and sizes.
Cell Body
The metabolic center of the neuron - filled with cytoplasm.