Biology: Genetics Terms Flashcards

Terms Definitions
four chromatids
the obsereved type
division of nucleus
may skip a genereation
Klinefelter Syndrome
1 in 1000
Small testies
Reduced facial and pubic hair
Taller and Sterile
meiotic non-dysjunction most frequently occurs during Meiosis 1. what is not separating properly
required to initiate transcription
RNA Polymerase
polymerizes ribonucleotides into RNA
as chromosome separation proceeds, chiasmata move toward the ends of the tetrad
Traits from parents express equally
replication fork
point of DNA separation
method of transformation; dissolve cell wall, electrical pulse to create channels, and regrowth of cell wall
Gemmules carry information from various parts of the body to the reproductive organs, from which they are passed to the embryo at the moment of conception. Persisted until the late 1800's.
XXY sterile male, cannot reproduce
if the two alleles are different
pre-zygotic isolating mechanisms
1)geographic isolation2) ecological isolation (tree/base of tree)3)Temporal isolation (species reproduce in different seasons/times of the day)4)behavioral isolation (a bird sings better than another)5)mechanical isolation (structural differences)6) prevention of gamete fusion
process in which mRNA is synthesized/formed from the DNA template.
Micro array
Technique in which single-stranded cDNA or DNA is placed on a gel, and unknown sequences are added to see where they line up.
phenomenon of a single gene determining a number of distinct and seemingly unrelated characteristics
first stage of mitosis
dna coils tightly
microtubules  form
membrane breaks down
nucleolus disappears
what are darkly staining, non-coding regions of a csome called?
variable number tandem repeats; highly variable among individuals; used as DNA fingerprints in forensics
percentage of individuals with a particular genotype that express the phenotype expected of the genotype
two-point testcross
cross between an individual heterozygous at two loci and an individual homozygous for recessive alleles at those loci.
An illustration in which the chromosomes of a cell are arranged according to their size.
What did Mendel experiment with?
Pea plants.
having two similar complements of chromosomes.
the gentic makeup or combination of alleles   
bacteria that can grow on minimal medium
Chromosomal Abnormalities
diffrent from normal number of chromosome ot normal arrangement of genes on chromosome
Form of cell division that produces two cells, each of which has the same complement of chromosomes as the parent cell.
gene with only 1 wild type allele
(agouti mouse)
Chromatin Structure: 
30 nm fiber
nucleosome-beads. DNA wrapped around 8 histone proteins. Little nuclease cuts beads into ~200 bp. More nuclease ~147 bp
chromatosome-nucleosome and histone H1. the h1 acts as a clamp and binds the DNA to the histone (20 bp).
30 nm fiber-this stucture is formed by histones folding on themselves 
annealing rate
rate at which fragmented DNA reconnects
Set of pathways that break down molecules into smaller units and release energy
Responsible for sealing up nicks in DNA
multiple gene pairs for the same phenotype
multiple factors that contribute to a trait either biological or environmental
continous trait that varies of a range measurement
quantitative trait that is controlled by two or more genes
production of gametes in a male animal
What type of cancer may be inherited?
heterozygous mutations can be used to locate genes via?
A retinal tumor that is 90% penetrant
amino-acyl synthetase
catalyzes amino acid addition to tRNA
Phenotypes that vary within a species
Variable traits
Chromosomal mutation
mutation that occurs at the chromosome level resulting in changes of the gene distribution to gametes during meiosis: caused when parts of chromosomes break off or rejoin incorrectly
male and female sex cells, sperm and eggs
Define "Meiosis"
cuts chromosomes in 1/2 by seperating homologs
Which of the following RNA types is involved in removal of introns in pre-mRNA?
Multiple Alleles
Genes that have more than two alleles.
Duplicate recessive epistasis
9:7 ratio resulting from gene interaction along a single pathway
linked genes
Genes that are inherited together with the other gene(s) as they are located on the same chromosome.
Second Filial
The first offspring from the first filial cross; second generation from parent generation
A protein that binds to a cis-acting element such as an operator or silencer, thereby preventing transcription from an adjacent promoter
secondary structure
spiral or pleated compilation or amino acid sequence
Induced Mutation
Occurs when an organism is exposed either deliberatly or accidentally to a physical or chemical agent. seen more frequently than spontaneous mutations.
Heterogametic sex
when they produce two kinds of gametes; in humans and drosophila= males (XY)
Waht is W?
recalibrating allele frequency due to selection
selection coefficient that subtracts from 1
DNA ligase
an important enzyme in DNA replication and repair that seals the DNA backbone by catalyzing the formation of phosphodiester bonds (connects Okasaki fragments)
Restriction Enzymes
These enzymes recognize and cleave DNA at specific sequences
formula that represents a karyotype that has an extra copy of chromosome 13?
2n + 1
transfer of the male pollen grains to the pistol of a flower
proteins that the DNA of eukaryotes is wrapped around for organizational and size purposes.
recessive allele
an allele whose phenotyic effect is not observed in a heterozygote.
Down's Syndrome
- a classic case of trisomy
- caused by trisomy of chromosome 21
- can also be caused by the translocation of a chromosome 21 fragment
- symptoms: short stature, have characteristic facial features, mental retardation, sexually under-developed, have shorter-than-normal lifespans
Triploid Cell
When two sperm fertilize, one ova, at the same time.
Thomas F. Morgan
started experiments to show that some traits were sex-linkedfrom Columbia University
incomplete dominance
when alleles blend to form a third phenotype
law of segregation
law stating that pairs of genes separate in meiosis and each gamete receives on gene of a pair.
RNA synthesis (Eukaryotes)RNA polymerase 1
only synthesizes 2 large rRNA molecules: 18S and 28S
intragenic and extragenic
two different types of suppressor mutations
Allelic Frequency
frequency of all alleles at a locus. To calculate genotype frequency divide the three classes AA, Aa, aa by the total number in sample
AA= 90=.9
Yeast Artificial Chromosome
modified plasmid that contains a yeast centromere and a yeast origin of replication; can carry relatively large pieces of DNA to be inserted into eukaryotic cells
Wild Type
the trait or allele that is most commonly found in natural (wild) populations
The study of how the proteins of a cell or organism work together to control function and determine phenotypes.
What is anagenesis?
evolution within a lineage with the passage of time
-          What is an Hfr cell? Study the figures
-          High Frequency Recombination Cell
-               Designation for an E. coli cell that has an F factor integrated into the bacterial chromosome.  When an Hfr cell conjugates with a recipient (F-) cell, bacterial genes are transferred to the recipient with high frequency.
-               Figure 18.5
Frame Shift Mutation
mutation that causes a change in the reading frame and results in a different protein
(Deletion and Insertion)
single stranded binding protein (SSBP)
complex DNA to keep strands open
Beadle and Tatum
First to show that genes could be involved in the production of enzymes, using Neurospora.
core promoter
set of cis (on the same side)- acting sequence elements needed for the transcription machiner to start RNA synthesis at the correct sit.
Describe the phenotype, cause, incidence, and treatment for Spina Bifida
Failure of midline closure at spine.Risk: 1/1,000.Reoccurrence risk: 3-5 %.Phenotype varies from mild to severe.
Endogenous gene
a gene that is normally present in an organism, in contrast with a foreign gene from a different organism that might be introduced by transgenic techniques
What happends to holliday junction that is fully zipped up?
holliday intermediate of non homologous chromosomes is formed as they disengage to form an X
endonuclease cuts holliday intermediate
What is a hybrid/heterozygous?
consisting of 1 dominant and 1 recessive gene.
leading strand
the strand that is made in the 5' to 3' direction by continuous polymerization at the 3' growing tip (DNA continually extended in 3' direction as double helix opens)
Synonomous Mutations
If a nuc in the 3rd position of a codon undergoes a transition mutation, the same amino acid is still coded for
tandem gene family arrays
genes which code for a product needed in great quantities that are arranged in adjacent repeats along the chromosome
The Gower manuever is a sign of what condition?
Duchenne muscular dystrophy
What are the two key characteristics of stem cells?
They can divide
They can differentiate into one or more cell types.
besides the nucleus where is dna found
at chloroplasts and mitochondria, and for some bacteria plasmids
Quantitative Trait Locus (QTL)
The position on a chromosome of a gene that contributes to a quantitative trait.
How does Abberrant Euploid affect gene balance?
Abberrant Euploid does not affect gene balance
When 2 mutants give a wildtype...
Do complement each other and they are separate genes
Do cycadian rythams depend on external signals?
no, but theyr internal clocks can be thrown off by the external jet lag
what is the telomere problem?
DNA is lost at the ends of the linear eukaryotic DNA because of the removal of primers
You map a mutation in a gene and find that is it located near the 5' end of the mRNA. Where would the changed amino acid be located in the protein
at the amino-or N-terminus of the protein
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