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Adaptation = a new and beneficial trait. Adaptations increase the ability of an organism to survive in its environment and produce offspring.
Adaptations (new beneficial traits) arise from spontaneous mutations. Creatures don’t choose to change!
Amino acids = there are 21 different kinds of amino acids that make protein. (These are like bricks.)
The subunits that join together to make proteins.
Alleles
Alleles
Allele = A factor or letter that makes up a gene. An allele is a different form of a gene. 2 alleles make up one gene.
"B" and "b" are different alleles.
Alleles = "B" and "b" are different alleles.
Autosomal = refers to genes that are not found on the sex chromosomes.
Autosomal chromosomes are ones that are not XX and XY.
Autosomal conditions affect both males and females.
Anticodon = A sequence of 3 letters found on TRNA that pairs with the codon of MRNA.
Bases = parts of DNA that make up your genetic code. These are known as nitrogenous bases. The bases are Adenine, Thymine, Guanine, and Cytosine.
A matches with T and G matches with C.
The sequence of bases makes up your genetic code.
Carrier = a person who has a recessive allele and a Dominant allele.
In the case of Tay Sachs, a carrier would have this genotype: (Nn); the recessive allele is harmful.
A brown-eye person who has a hybrid gene (Bb) can also be considered a carrier because the person carries the recessive allele for blue eye color, (b).
Chromosomes
Chromosomes
46 chromosomes are found in human cells.
Genes are carried among chromosomes. Chromosomes are made of DNA and hold the alleles of your body. They and the genes determine how a baby's body forms during pregnancy and how the body functions after birth.
Codon = A sequence of 3 letters on MRNA that code for amino acids.
A codon can also tell when to start and stop translation.
Color Blindness = a sex-linked recessive condition where people cannot see colors in a normal way. The condition mostly affects males.
Crick: Francis Crick and James Watson = Discovered DNA's famous double helix structure. Published in 1953. They won the Nobel Prize in 1962.
Cystic Fibrosis = Autosomal recessive. Mucous in lungs... Death in the 30s.
Cytoplasm = The part of the cell that lies outside of the nucleus. It is comprised of the cytosol and the organelles.
Darwin, Charles = developed The Theory of Natural Selection that states "those individuals who possess superior physical, behavioral, or other attributes are more likely to survive than those which are not so well endowed."
Dihybrid = a creature with two hybrid genes. For instance, (Aa, Bb) is a dihybrid cow.
A dihybrid always makes 4 different kinds of gamete:
Big-Big
Big-small
small-Big
small-small
DNA = The main instructions that explain how to build the body.
(Deoxyribose Nucleic Acid) DNA makes up alleles, genes and chromosomes.
Dominance = This is one of Johann Gregor Mendel’s laws. In his studies with pea plants, Mendel notices that pure tall plants bred to pure short plants resulted in tall hybrid plants. Tallness was dominant to shortness.
TT * TT ==> TT
TT * tt ==> Tt
Tt * Tt ==> TT, Tt, Tt, and tt
Dominant = an allele that overpowers another is dominant.
For instance, B overpowers and masks b. Brown eyes are dominant to blue eyes.
Down Syndrome
Down Syndrome
Down syndrome is a condition in which a person has an extra 21st chromosome. Typically humans have 46 chromosomes.
The condition occurs when homologous chromosomes do not separate properly during meiosis.
Franklin, Rosalin = Her x-ray crystallography work with DNA was used (without her knowledge) to crack the structure the DNA double helix.
Enzyme = A type of protein that controls the rate of a biochemical reaction.
Eukaryote: these organisms have a distinct nucleus and organelles have membranes.
Eukaryotes include all living organisms other than eubacteria and archaebacteria.
You are a eukaryote.
Evolution = any process of change over time.
Evolution is a change in the traits of living organisms over generations, including the emergence of new species.
Since the development of modern genetics in the 1940s, evolution has been defined more specifically as a change in the frequency of alleles in a population from one generation to the next.
Evolution is a change in the heritable traits of a population over many generations.
Evolution is caused by:
Evolution is caused by:
Mutation (good, bad, or neutral)
Variation
Natural Selection
Fitness (Reproductive Success)
Fit = An organism that produces a large number of offspring is deemed fit.
(Fitness has nothing to do with the size or strength of the critter-it is all about passing genes on. Bunnies are fit. Frogs are fit.)
Gamete = means sperm or egg. Germ Cell. In humans, a germ cell contains 23 chromosomes.
Gene = Every trait is controlled by a gene. A human has roughly 20,000 genes. Genes are controlled by 2 factors called “alleles”. Each allele comes from a parent. Bb, NN, and ee represent three genes.
Genotype = All the genes of a beastie equal the genotype of the beastie. (Genes an organism possesses). Here is a genotype of a mythical creature with 8 genes.
(Aa, Bb, cc, DD, ee, Ff, GG, hH)
Germ Cell- An egg or sperm cell. A gamete. In humans, a germ cell contains 23 chromosomes.
Helix = Is a three-dimensional curve. It is like a spiral staircase.
Hemophilia = sex-linked recessive. Males get it most often. XN Xn = carrier female. Xn Y = affected male.
Heterozygous = this means alleles of a gene are "different".
Aa is heterozygous.
Bb is also heterozygous. See hybrid.
Homozygous = when alleles of a gene are "the same”.
BB, nn, and ee are all homozygous.
Huntington's Chorea = Autosomal Dominant.
People die at 40 +... Jerky muscular motions
Hybrid = means alleles of a gene are "different" (Hh)
See heterozygous.
Hydrogen Bonds = connect bases in the DNA molecule. The bond results between a positive hydrogen atom in one molecule and an electronegative atom in the other.
Independent Assortment: This is Johann Gregor Mendel’s 3rd law. It states that alleles of one gene separate independently from alleles of another gene. In other words, eye color does not affect a person’s ability to roll his or her tongue.
Mendel, Johann Gregor
Mendel, Johann Gregor
The father of genetics.
1) In 1866 he published a paper that said that traits are controlled by 2 factors. One factor is said to be dominant if it overpowers a recessive factor.
2) These factors (alleles) segregate during the formation of gametes.
3) Alleles assort independently from one another.)
Mitosis = the kind of cell division that splits an original cell into 2 identical daughter cells.
Mitosis causes you to grow. Mitosis replaces old cells.
Interphase is the resting phase. Prophase starts the process. The chromosomes and their copies line up at Metaphase. During Anaphase the chromosomal copies are separated. In telophase, the chromosomes are very far apart. Cytokinesis forms two new cells.
MRNA = This type of RNA matches with DNA and then moves to the ribosome. It is like a photocopy of the DNA. Messenger ribonucleic acid.
MRNA is transcribed from DNA and carries the instructions about how to make a protein to the ribosome.
Mutation
Mutation
An accidental change in a gene that can be either helpful, harmful, or neutral. DNA mutations result in genetic variation within a species.
A change in the DNA instructions. A change in the DNA sequence. The change can be beneficial, detrimental or neutral. It ultimately results in a change in protein. For instance, random genetic mutation gave rise to the dark phenotype of the peppered moth.
Natural Selection = Darwin said that the process that eliminates creatures with inferior traits and preserves those with superior traits is known as natural selection.
Critters with good traits will be selected by nature to survive. Those organisms that survive are more likely to produce offspring with the same advantages for survival thus increasing the population of the organism. Critters with negative traits will die off.
Non-Disjunction:
Non-Disjunction:
When homologous chromosomes fail to segregate properly during meiosis. Down syndrome, Turner syndrome and Klinefelter syndrome result from non-disjunction.
Nucleotide = One of the four DNA chemical submits:
(A + sugar and phosphate),
(T + sugar and phosphate),
(G + sugar and phosphate),
(C + sugar and phosphate).
3 billion nucleotides make up a human's genetic code.
Nucleus
Nucleus
Nucleus (Cell) = This is like the brain of a cell. It is like a reference library because it contains the DNA which explains how to run the cell.
All eukaryotic cells have nuclei.
Phenotype
Phenotype
Phenotype = the way an organism looks. The appearance.
Polydactyly
Polydactyly
This is a condition that results from a dominant allele. The condition is autosomal dominant.
Population
Population
A group of the same species occupying a particular geographic region. The picture to the right shows the range of the alligator population.
Prenatal = means "before birth"
Prokaryotes: Bacteria! These microscopic single-celled organism do not have a distinct nucleus. They don't have membranes or specialized organelles. Prokaryotes include the bacteria and cyanobacteria.
Protein = Skin, antibodies, muscle, hormones, are examples of protein (finished product) A long chain of amino acids. Enzymes, pigments etc.…
Punnett Square
Punnett Square
The Punnett square is a tool still used by biologists to predict the probability of possible genotypes of offspring.
Reginald Crundall Punnett is the creator of this tool.
Recessive = A small, weaker allele is recessive.
Blue eyes are recessive.
Their genotype is represented by the bb genotype.
Reginald Crundall Punnett
Reginald Crundall Punnett
Reginald Crundall Punnett is the creator of the Punnett square, a tool still used by biologists to predict the probability of possible genotypes of offspring.
Ribosome = this is where MRNA matches with TRNA and construction occurs. The site of protein construction. Ribosomes move along the MRNA as it is translated into protein.
Segregation = This is one of Mendel’s laws. Mendel said that all genes are comprised of 2 factors, one from each parent. Chromosomes segregate during meiosis. These factors (alleles) of a gene separate during the formation of gametes (sperm and egg). This ensures that each parent contributes 50% of their genetic information.
Scientific Law = a mathematical way of explaining reality. The following equation shows how energy is conserved.
This is Newton's 2nd. It explains and predicts how masses accelerate when acted on by a net forces.
Scientific Theory = a very detailed explanation based on facts. A theory is repeatedly confirmed by science. It is not a guess or a hunch.
Sex chromosomes = chromosomes that determine gender (XY and XX)
Sex-Linked Recessive Conditions - Hemophilia and Color Blindness are both sex-linked conditions. This means that the recessive allele is carried on the x-chromosome, one of the sex-chromosomes. It also means that males are more apt to show the condition. Sex-linked conditions are x-linked! They are on the x chromosomes.
Somatic Cell = Body cell that contains 46 chromosomes in humans.
Sugar = Deoxyribose sugar. Found in backbones of DNA helix. Attaches to bases (AT, GC). Alternates with phosphate in the backbones.
Tay Sachs = Autosomal recessive. Children die young. Head enlarges...
TRNA = This matches with MRNA and also carries an amino acid. (Transfer RNA is like a truck). Transfer ribonucleic acid. a type of RNA that carries an amino acid to the MRNA on the ribosome.
Trait = is a feature of an organism.
Transcription = The process of copying DNA into MRNA
Translation = The process of converting MRNA into protein.
Trisomy
Trisomy
Trisomy = When three copies of a chromosome are present instead of two. Normally, all chromosomes come in pairs. Down syndrome is the result of three chromosomes of number 21.
Uracil = in RNA, this base matches with Adenine instead of Thymine.
Variation = in any population of critters, some are different from the others. For instance, the variation within the peppered moth population allowed the species to survive under the changing environmental conditions. Variety!
In a population, critters are different – due to mutations. Variation increases the chances that some individuals will survive - ultimately preserving the species.
Watson: Francis Crick and James Watson = Discovered DNA's famous double helix structure. Published in 1953.
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