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Flashcards in Genetics Deck (77):
0

Gregor Mendel

Monk, pea plants bc easy to grow and he can control pollination and traits are easily observable and they make intercourse a lot

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Pollination

Fusion of pollen (sperm) and egg to form a seed

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Alleles

Different forms of the gene for a specific characteristic

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Genotype

Genetic makeup of individual (Tt, DD, Yy)

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Phenotype

Traits that actually appear on a dude (tall, short, sexy, big D)

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Heterozygous

Hybrid, 2 alleles for the trait are different (Tt)

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Homozygous

Pure (no mudbloods) two alleles for trait are the same (TT or tt)

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Law of dominance

Heterozygous individuals will express the phenotype of the dominant alleles (Tt tall will be expressed)

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Test cross

To tell if an individual is pure by crossing with homo recessive (if all babies dominant, homo, if some recessive, hetero)

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Law of segregation

Alleles separate during meiosis and recombine during fertilization (if offspring r diff phenotype than parents...VARIATION)

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Law of independent assortment

Traits are inherited independently of eachother, traits not linked

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Mendel's 3 laws

Law of dominance, law of segregation/recombination, law of independent assortment

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Incomplete dominance

Aka blending, only partially dominant, intermediate phenotype (redXwhiteXpink, RR R'R' RR')

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Codominance

2 dominant alleles equally expressed, ex Roan cattle (red and white)

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Sex determination

Determined by sperm (male: XY+22 pairs of autosomes, female: XX+22 autosomes)

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Sex linked traits

Disorder linked to the X chromosomes (hemophilia/color blindness, most common in makes, only need to get from mom, XX)

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Gene linkage

Genes for 2 diff traits are located on the same chromosome and can be inherited together, ex red hair/freckles (exception to Law of Ind Assort)

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Crossing over

Exchange of genetic material during Synapsis in meiosis GENETIC VARIATION IN GAMETES (if it occurs b/w non-homologous=genetic disease)

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Multiple alleles

>2 alleles for a given trait, ex blood typing has 3 alleles IA IB and i

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Blood typing alleles info

IA=type A; IB=type B; i=type O
Type A and B are codon infant over O, so type O (or i) is recessive

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The double helix was discovered by

Watson and Crick

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What are the purines?

Nitrogenous bases Guanine and Adenine (double linked ring of atoms)

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What are the pyrimidines?

Nitrogenous bases cytosine, thymine, and uracil (single ring of atoms)

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What do hydrogen bonds do?

Hold together the two strands of DNA that run anti-parallel to eachother

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Carbons on the 5 carbon sugar on nucleotides

1' carbon is bonded to nitrogenous base, 3' to the next nucleotide, 5' to the phosphate group

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5 carbon sugar in RNA vs DNA

RNA=Ribose, DNA=Deoxyribose lol whadoyouknow

27

Lemme unzip your genes (with the enzyme..)

Helicase! U hoe untwisting/breaking them hydrogen bonds

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DNA polymerase

Adds new nitrogen bases into the 3' end, forming new stands

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Lagging strand

Made in pieces called Okazaki fragments (more like fragments of my HEART...after watching Clannad :'(

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DNA ligase

Links together Okazaki fragments

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Leading strand

DNA strand that is read in the 3' to 5' direction but is synthesized in the 5' to 3' direction in a continuous matter (original)

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Gene

Segment on DNA, codes for making a PROTEIN (doesn't code for amino acid, codes for SEQUENCE)

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Transcription

DNA>mRNA copying of DNA to synthesize RNA in NUCLEUS

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Translation

mRNA>amino acid sequences MAKING PROTEIN in RIBOSOME (sequence of nucleotides codes for sequence of amino acids)

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Codon

Triplet of nucleotides on mRNA that codes for one amino acid

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Anticodon

Triplet of nucleotides in tRNA

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What is self replicating?

ONLY DNA

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One gene is

One polypeptide

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Hemoglobin is made of how many polypeptide chains?

4

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Attraction and repulsion between what group in the polypeptides?

Carboxyl and amino group

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3 stages of transcription

Initiation elongation termination

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Initiation

RNA polymerase binds to promotor

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DNA promotor (in initiation)

A specific nucleotide sequence in the DNA at the start of a gene; instructs RNA polymerase where to start transcribing RNA (like the "cap")

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Elongation

•RNA polymerase moves along DNA
•Untwists DNA and turns around 10 bases at a time
•Adds nucleotides to the 3' end of the growing RNA
•60 nucleotides/ sec

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Termination

Termination site on DNA i.e AATAAA signals RNA polymerase to stop transcription ("tail")

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Cap and tail

2 ends protects RNA molecule from degeneration

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Gene splicing

Introns: non coding sequence of genes "spliced" out before translation
Exons: the coding region of a eukaryotic gene that is EXPRESSED in genotype

48

Ribosome

Made up of 2 subunits (large/small)
Constructed in nucleoli, contains RNA and protein, 3 binding sites; 1 attach to mRNA and 2 for tRNA

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P-site

Holds tRNA to the growing polypeptide chain after amino acid is added

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A-site

Holds tRNA attached to the next amino acid to be added

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2 tRNA sites

A and P site, A (amino)> P (polypeptide)

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4 stages of translation

Codon recognition
Peptide bond formation
Elongation
Termination

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Elongation

Of polypeptide via movement of tRNA from A to P site on the ribosome, this allows the next codon/anticodon recognition to take place

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Termination

Stop codon reaches A site in the ribosome

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Heredity and the environment: light and chlorophyll

No light, no chlorophyll

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Environmental effect: temp and hair color

Lower temps, hair on Himalayan rabbits will grow back darker

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Identical twin studies

Comparing those separated at birth/not

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tRNA and DNA are

Not complimentary

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mRNA to DNA and tRNA

It's complimentary (opposite)

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Mutation

Any change in genetic material aka base code during meiosis, must be in sex cells (damaged)

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Mutagenic agents

Radiation chemicals X-rays UV rays cause mutations

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Genetic mutation

Change in DNA sequence>change in amino acid sequence in protein

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Big idea

•DNA determines amino acid sequence
•Amino acid sequence determines protein shape which determines function

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Point mutation

One nucleotide is changed for another MINOR (occurs in one gene)

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Frame shift mutation

Addition or deletion of one or more nucleotides that shifts the whole reading DEVASTATING (occurs in one gene)

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Chromosomal mutations

Can be detected by looking at a Karyotype (picture of chromosomes)

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Nondisjunction

Chromosomes don't separate properly during meiosis (anaphase)
Results in one extra/one less chromosome
i.e Down syndrome (trisomy 3 21st chromosomes)

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Polyploidy

Extra set of chromosomes- plants, positive, increases survival/more hardy 3N, 4N

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Deletion and Addition (insertion)

Portion of chromosome lost/added

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Inversion

Section of chromosomes switched upside down

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Translocation

Section of chromosome transferred to another during cross over

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Nucleotide parts

Circle=phosphate, house=sugar, rectangle=nitrogenous base

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Does the mRNA or tRNA codon correspond to AA (amino acid)

mRNA

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Essential amino acids..

Must be acquired from external food source

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In semi conservative DNA replication..

Each strand of the double helix serves as a template for the synthesis of its new partner

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Hemophilia

Recessive mutation, x linked, improper blood clotting, cannot see with Karyotype

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Sickle-cell anemia

Red blood cells sickle shaped, homozygous, Karyotype=3 in the 21st