Bio 150 genetic variation (idvividuals)

Locus

Locus

Specific physical location on a chromosome where a gene is located

Gene

Segment of DNA that contains instructions for making proteins or functional RNA modules

Allele

Different versions or variants of a gene that can result in different traits

Mutation

Change in the DNA sequence of a gene that can create new alleles or alter the function of existing alleles

Protein

Large molecule made of amino acids that plays various roles in cell structure and function

Haploid

Cell or organism with one complete set of chromosomes

Diploid

Cell or organism with two complete sets of chromosomes

Chromatin

Complex of DNA and protein found within the nucleus of eukaryotic cells that packages DNA into a more compact structure

Chromosome

Thread-like structure made of DNA and proteins that carries genetic information

Base sequence

Specific order of nucleotide bases (adenine, thymine, cytosine, and guanine) along a DNA molecule

Gene expression

Process by which the information in a gene is used to synthesize a functional product, usually a protein or RNA module

Regulation

Mechanisms that control when and how genes are turned on or off

Genotype

All the information stored in an organism's cells

Phenotype

Physical characteristics or traits of an organism

Nonsense mutation

Mutation that changes a specific allele into a stop codon, potentially altering the physical aspects of an organism

Missense mutation

Mutation that changes a specific allele into a different amino acid, potentially altering a physical aspect

Deletion

Chromosomal rearrangement where a piece of a chromosome breaks off and is lost

Duplication

Chromosomal rearrangement where a piece of a chromosome flips and reattaches, resulting in an extra copy

Translocation

Chromosomal rearrangement where a piece of a chromosome breaks off and attaches to a different chromosome

Inversion

Chromosomal rearrangement where a piece of a chromosome breaks off, flips, and reattaches in the opposite orientation

Recombinant genotype

Genotype resulting from chromosomal segregation during meiosis, leading to new combinations of chromosomes

Ploidy

Number of sets of chromosomes in a cell or organism

Alternative splicing

Process of splicing different combinations of exons together to create multiple mature mRNA molecules from one gene

DNA replication occurs

nucleus of a cell

DNA to RNA transcription

During transcription, one strand of a DNA double helix serves as a template for assembling a single, complementary strand of RNA (a transcript)

RNA to protein also known as ________

takes place in cytoplasm, mrna template used to build proteins from amino acids

semi-conservative synthesis

Works like a template, original strand gets replicated

Replication starts with the __________ of the double helix and __________ of new __________ strands on each of the separate DNA strands

unwinding, synthesis ,DNA

In eukaryotes, transcription occurs in the

nucleus

In eukaryotes, translation occurs

outside the nucleus

introns and exons

Introns are removed from the mRNA sequence, while exons remain

mRNA

messenger RNA; type of RNA that carries instructions from DNA in the nucleus to the ribosome

Ribosome

Makes proteins

Proteins

amino acids

genetic code

The nucleotide triplets of DNA and RNA molecules that carry genetic information in living cells.

Different cells transcribe different parts of the DNA also known as

differential gene expression

RNA and _____ differ between cells, but the _______ in each cell is the same

proteins , DNA

Complexity of organisms is a function of number of ______ and differential gene _______ and __________ splicing

genes, expression, alternative

Phenotype

physical traits that are a product of the proteins produced

Differences in _________ may cause differences in __________

genotype, phenotype

Fitness

how well an organism can survive and reproduce in its environment

Mutation creates ______

variation

Mutations in DNA cause

Disorders, cancer, sometimes evolution

true or false: all the mutations that occur in your body's cells are passed on to your offspring

False

somatic cells

make up most of your body tissues and organs/ function

somatic cells are divided by

mitosis

germ cells

reproductive cells that give rise to sperm and ovum

Mutations that occur in germ cells are passed on too_______

offspring

Mitosis occurs in

somatic cells (body cells)

Meiosis occurs in

germ cells aka sex cells

Mitosis chromosomes line up

single file

Meiosis chromosomes line up

double file

Mitosis Daughter Cells are....

identical

Meiosis daughter cells are

genetically different (due to crossing over)

asexual reproduction

Process by which a single parent reproduces by itself

Examples of asexual reproduction

bacteria, protists

single nucleotide polymorphism (SNP)

One base-pair variation in the genome sequence

Null model of evolution

no change in gene pool across generations

Evolution

change in allele frequencies in a population over time

Allele

An alternative form of a gene.

Hardy-Weinberg equilibrium

population large, random mating, no mutation, no migration, no natural selection

Microevolution

Change in allele frequencies in a population over generations.

macroevolution

large-scale evolutionary changes that take place over long periods of time

Heterozygotes often have greater _______ in variable environments

fitness

frequency of heterozygous genotype is ________ with each generation of inbreeding

reduced

How are new species formed?

when populations diverge enough to exhibit species level differences

Ploidy

number of sets of chromosomes in a cell

Taxon

group or level of organization into which organisms are classified

typological thinking

based on the idea that species are unchanging types and that variations within species are unimportant or even misleading

plato

typological thinking

Aristotle

typological thinking + scale of nature

Scale of Nature

fixed species on a continuum from simple to complex

Lamarck

change through time and scale of nature

Darwin and Wallace

Individuals in a population are different; species arise through the process of natural selection

Evolution by natural selection

can be tested experimentally and observationally

Darwin's observations

variation within population, variation passed to offspring, survival and reproduction are not random, organisms reproduce more than can survive

Homologies

Similarities between organisms based on descent from a common ancestor.

Homoplasy

convergent, or parallel, evolution, as when two species with very different evolutionary histories develop similar physical features as a result of adapting to a similar environment

Speciation

the evolution of new species

Natural selection components are variation within_________, some of the variation is __________, the variation affects ______________

populations, heritable, fitness

directional selection

Form of natural selection in which the entire curve moves; occurs when individuals at one end of a distribution curve have higher fitness than individuals in the middle or at the other end of the curve

stabalizing selection

natural selection that favors average individuals in a population; results in a decline in population variation

disruptive selection

form of natural selection in which a single curve splits into two; occurs when individuals at the upper and lower ends of a distribution curve have higher fitness than individuals near the middle

not only survival of the fittest but ___________ of the fittest

reproduction

Adaptation

traits good for the current environment

when humans apply the principles of natural selection, we select for ___________ traits and shape of the populations over time, changes are _________ because we apply __________ pressure

particular, fast, high selection

changes in allele frequency

-gene flow

-natural/sexual selection

-mutation

-genetic drift

When has evolution occurred?

If the gene pool changes or if a new allele is introduce by a mutation

genetic drift

A change in the allele frequency of a population as a result of chance events rather than natural selection. RANDOM

bottleneck effect

A change in allele frequency following a dramatic reduction in the size of a population

non-random mating

mating between individuals of the same phenotype or by those who live nearby

non-random mating leads to no __________ frequency changes, but ___________ of heterozygotes

Allele, loss

Emigration

movement of individuals out of a population

Immigration

Movement of individuals into a population

Individuals do not evolve, _______________ do.

populations

Evolution is not for the ________ of a species

good

Evolution is a response to the current environment and does not anticipate the _______

future

Mutations are ________, natural selection is ________

random, not

Genome

the complete instructions for making an organism, consisting of all the genetic material in that organism's chromosomes

Genes determine what?

character or traits are displayed