BIO 140.01 - Module 2: Structure of DNA and the Human Genome

Blending hypothesis

Hypothesis that says traits and attributes from two parents blend together

Particulate hypothesis

Hypothesis that says parents pass on discrete on-bleeding heritable units onto their offspring

Particulate hypothesis

Gregor Mendel proposed what hypothesis

Gregor Mendel

Father of Genetic

Pea plants

Gregor Mendel studied heredity using ___

Paired unit factors, dominance/recessiveness, segregation, independent assortment

Mendel established four postulates: ___,___,___,___

Walter Sutton, Theodor Boveri

Two scientists who suggested that unit factors were contained in chromosomes

Frederick Griffith

Performed transformation experiments on bacterial cells

Transformation

Refers to the genetic alteration of a cell by direct uptake of extracellular material

Streptococcus pneumoniae

Virulent/non-virulent strains of ___ used by Griffith

Smooth

Virulent strains were ___ (smooth/rough) under the microscope

Rough

Non-virulent strains were ___ (smooth/rough) under the microscope

Avery, McLeod, McCarthy

Scientists who performed degradation experiments to demonstrate DNA as the transforming agent

Hershey, Chase

2 scientists who used a T2 bacteriophage to determine whether DNA or protein carried genetic information

False

T or F: The T2 bacteriophage consists of a protein capsid surrounding an RNA core.

False

T or F: The protein capsid of the T2 bacteriophage enters the bacterial cell to transfer genetic material.

Watson, Crick

2 scientists who published proposed structure of DNA

Rosalind Franklin

Scientists whose x-ray image showing the helical structure of DNA (Photograph 51) were central to Watson and Crick’s discovery of the DNA structure

False

T or F: Deoxyribonucleic Acid is composed of DNA nucleotides linked together by n-glycosidic bonds

5’ to 3’

Directionality of DNA

False

T or F: DNA is composed of two strands running in the same direction

Hydrogen bond

What kind of bonding can be found between base pairs

Erwin Chargaff

Scientist who observed Adenine (A) pairs with Thymine (T), and Cytosine (C) pairs with Guanine (G) in nearly equal amounts in DNA

Primary

(DNA structure) Sequence of nucleotides

Secondary

(DNA structure) Base complementation with opposite strand through H-bonds

Tertiary

(DNA structure) 3-D Helical conformation, right-handed helix

B

Most common conformation of DNA as observed by Watson and Crick

A

More compact conformation of DNA that occurs in dehydrating conditions

Z

Conformation where DNA adopts a left-handed helix and occurs in high-salt environments

Triple helix

Conformation that can occur during DNA recombination and repair

0.34 nm

Height between base pairs

3.4 nm

Pitch length of a DNA helix

10 bases

1 turn in DNA has how many bases

2 nm

Diameter of a DNA helix

False

T or F: The overall charge of DNA remains to be nonpolar despite the phosphate groups carrying a negative charge

True

T or F: The polarity of DNA resulted to major and minor grooves

Major groove

Major binding site for enzymes and proteins in DNA

True

T or F: High temperature, urea, and alkalines are considered to be denaturants

False

T or F: Melting point of DNA is determined by AT content

False

T or F: Renaturation re-establishes the phosphodiester bonds between base pairs

True

T or F: You can anneal complementary strands between a human and a mouse to form a hybrid strand even if they are from different organisms

True

T or F: The average length of DNA is 9 million kilometers

False

T or F: Prokaryotic cells have more DNA than eukaryotic cells

Tertiary

DNA helix is the ___ structure

Quaternary

The chromatin to chromosome is the ___ structure

DNA strand

The most basic level of chromatin organization is the ___

DNA around histones

1st level of chromatin organization

Solenoid Fiber

2nd level of chromatin organization where nucleosomes are packed into helical coils

Looped domains

looping solenoid fibers attach to a protein scaffold

Chromatid

3rd level of chromatin organization where looped domains are coiled into a helical structure

Metaphase

Chromatids are most condensed during ____

Chromosome

refers to two sister chromatids joined together at the centromere, most notable during metaphase

Gene

Specific sequence of DNA codes that codes for a particular character

Allele

Alternative versions of the DNA sequence of a gene that lead to variations of a character

Locus

Location in the chromosome where each gene is situated

FISH

(Acronym only) Method to determine a gene’s locus by synthesizing a single-stranded DNA with a fluorescent marker

Genome

Totality of genetic information belonging to a cell or organism

False

T or F: RNA carries an organism’s genome

Mitochondrial, chloroplast, plasmid

An organism's genome may include extrachromosomal elements such as: ___,___,___

Exons

Protein-coding regions of a gene

Introns

Non-protein-coding regions of a gene that are removed prior to translation

True

T or F: Only 2% of our entire genome is used

Regulatory DNA sequences

Non-protein-coding sequences of DNA that control gene expression. Some examples of this include promoters, enhances, silencers, and insulators.

Simple sequence repeats

Short sequence of nucleotides that are repeated over again in quick succession and can span millions of nucleotides

Segmental duplication

Large duplicated DNA segments found in multiple locations in the genome. Often involve entire genes or gene fragments (chunk of DNA).

Tandem repeats

DNA sequence that is repeated multiple times consecutively

Satellite DNA

DNA sequences composed of 5-100 bp and can reach 100,000-10,000,000 bp long

Minisatellite DNA

DNA sequences composed of 10-100 bp that repeats every 2-100 bp

False

T or F: Microsatellite DNA is used for DNA fingerprinting

Microsatellite DNA

DNA sequence composed of 1-5 bp and repeats every 5-50 bp

False

T or F: Repeated DNA with non-coding functions are considered to be genes because they get transcribed

Repeated, Coding

___(unique/repeated) DNA with ___ (coding/noncoding) functions code for rRNA and histone proteins

True

T or F: Repeated DNA with coding functions are repeated for faster production

Jumping Genes

Another name for transposons

Barbara Mcclintock

Scientist who discovered transposons by observing genomes that code for pigment production in multicolored kernels

Transposition

Transposon is excised by an enzyme then reinserted in the recipient DNA in a different location

Retroposition

The transposon is not excised but is transcribed into RNA then reverse transcribed into DNA that can insert itself in a new location

False

T or F: Unique sequences are more malleable to change in evolution

True

T or F: According to DNA conservation, conserved genes in evolution indicate they are critical and important for sustaining life

Genetic polymorphisms

Refers to the presence of two or more variations of a specific DNA sequence (gene) in a population

DNA sequence variation

Variation refers to differences in the nucleotide sequences among individuals within a population

Single nucleotide polymorphisms

Nucleotide substitutions and the most common form of DNA sequence variation

False

T or F: Single nucleotide polymorphisms can sometimes cause disease

True

T or F: A variation in eye color that occurs in >1% of a population is a single nucleotide polymorphism.

False

T or F: Copy number variation alters a person’s phenotype such as individual appearance, susceptibility to disease, and response to medication.

Genomic medicine

Method of using an individual’s genetic information to guide medical decisions

Copy Number Variation

Gene duplication and chromosomal duplication is a form of ___

X

Klinefelter syndrome is a genetic condition where a male is born with an extra copy of a ___ (X/Y) chromosome

21

Down Syndrome is a genetic disorder caused by the presence of an extra copy of chromosome ___ (number)

Structural Variation

Gross structural changes in the genome, often involving large segments of DNA at the chromosomal level

Cri du Chat syndrome

This syndrome involves the deletion in the p arm of chromosome 5

Ataxia

This syndrome involves the progressive deterioration of motor skills due to a copy part of chromosome 4 attaching to chromosome 12

Chronic myelogenous leukemia

This condition involves translocation between chromosome 9 and 22