Bio Final

What is the definition of a Gene

A hereditary unit

What are regions of the chromosome called?

Locus

What do genes control?

Specific traits

What is a character?

A heritable feature

What are variants of a feature called?

Traits

What did scientists think happened to genes?

The genetic material from mom and dad blended together (Blending Hypothesis)

What is the genetic hypothesis we go by now called?

Particulate hypothesis

What is the definition of particulate hypothesis?

Parents pass discrete inheritable units called genes

How came up with the Particulate Hypothesis?

Mendel (1822-1884)

What was the significant plant in Mendel’s Expierement?

A garden pea called Pisum Satirum

What were the phenotypes and genotypes of the P-Generation?

PP - Purple (1) and pp - white (1)

What were the phenotypes and genotypes of the F1 generation?

Pp - purple (4)

What were the phenotypes and genotypes of the F2 generation?

PP - Purple (1), Pp - Purple (2), and pp - white (1)

What did Mendel call genes?

Heritable Factors

What was Mendel’s Law of Segregation pt.1?

Alternative versions of genes account for various characters

What is an allele?

An alternative form of a gene

What are the differences between alleles?

A few bases

What was Mendel’s Law of Segregation pt.2?

For each character, an organisms will inherit one allele from both parents

What was Mendel’s Law of Segregation pt.3?

If the two alleles at the locus differ, the dominant one will determine the phenotype

What was Mendel’s Law of Segregation pt.4?

The two alleles you inherit separate during gamete formation

When do the alleles seperate?

Anaphase 1

What is it called when you breed an organism with a mystery genotype with a homozygous recessive individual?

A testcross

How did Mendel discover his first law?

By using a monohybrid cross (looking at single traits)

What did Mendel do to identify his second law?

He looked at a dihybrid cross (2 traits)

What is Mendel’s Law of independent assortment?

Each pair of alleles segregates independently to another pair of alleles

What are combinations of traits that are not seen in parents called?

Recombination phenotypes

What is co-dominance?

The appearance of more than one allele in a phenotype

What is an example of codominance in humans?

Blood type

What does the Law of Probability state?

The laws of segregation and independent assortments reflect the rates of probability

What can we use the rule of multiplication for?

Figuring our the probability of one genotypic/phenotypic outcome

What can we sue the rule of addition for?

Figuring our the probability of multiple genotypic/phenotypic outcome

Which shape on a pedigree represents male?

Square

What shape on a pedigree represents female?

Circle

Autosomal Recessive Disorders

Disorders that only show up in homozygous recessive organisms

Who discovered that embryonic development of sea urchins does not occur unless chromosomes are present in 1902?

Boveri

Who observed the separation of chromosomes into daughter cells during Meiosis in 1902?

Suttan

What is the Theory of Chromosomal Inheritance?

Chromosomes are how heritable traits (genes) are passed from parent to daughter cell

What is true of the law of independant assortment?

It only applies to genes that are on different chromosomes

What are linked genes?

Genes that are on the same chromosome that are inherited together

What are some X-Chromosome linked traits?

Color blindness, hemophilia, congenital diseases, etc.

What are some Y-Linked traits?

Hairy rims of the ears

How many genes are on the Y-Chromosome?

78 genes

How many base pairs are on the y-chromosome?

59 million

How much of the human genome is represented by the y-chromosome?

2%

How many genes are found on the X-Chromosome?

1100 genes

How many base pairs are on the X-Chromosome?

155 million base pairs

How much of the human genome does the X-chromosome represent.

5%

How many genetic disorders are associated with the x-chromosome?

300

Who proposed the idea of x-inactivation in 1961?

Mary Lyon

What does the theory of x-inactivation state?

That one of the X-chromosomes are randomly inactivated

Who preformed experiments on fruit flies in 1900?

Thomas Hunt Morgan

What did Thomas Hunt Morgan discover?

DNA is what houses genetic material

What did Fredrick Griffith do in 1928?

He experimented with a smooth and rough strain streptococcus pneumonia

Which strain of streptococcus pneumonia is harmless?

Rough strain

Which strain of streptococcus pneumonia is harmful?

Smooth strain

What happens when a s-cell came into contact with a living R-Cell?

The r-cell would transform into a s-cell

Who were the scientists that added onto Griffith’s work in 1944?

Oswald Avery, Maclyn McCarty, and Colin Maclead

What exactly did Avery, McCarty and Maclead discover in 1944?

Transformation only occurred with DNA that was active (the mice lived)

What is the technical definition of transformation?

The change of genotype or phenotype due to the acclimatation of foreign DNA

What is the definition of a virus?

RNA/DNA that’s enclosed in a simple protein

What did Alfred Hushey and Martha Chase discover in 1915?

The genetic material of a T2 phage is DNA

How did Hushey and Chase reach their conclusions?

They used radioactive material to follow phage DNA and phage protein after they’ve interacted with a cell

What was the result of the Hushey and Chase phage expierement?

They found the DNA in the cell and the phage protein in the seperate liquid

What is true about an organisms form in biology?

The function determines the form

Who officially designed the double helix of DNA in 1953?

Watson and Crick

What did the double helix model earn Watson and Crick in the 1970’s?

A noble peace prize

Who discovered that DNA composition varies between species in 1950?

Edwin Chargaff

What was the first Chargaff rule?

The base composition of DNA varies between species

What was the second Chargaff rule?

In any organism, the number of Adenine and Thiamine are equal and the number of Guanine and Cytosine are equal

When were Chargaff’s rules considered important?

When the double helix model came about

How did Rosalind Franklin and Maurice Wilkins study molecule structure?

X-Ray crystallography

Why was Franklin’s x-rays significant?

They produced a picture of the DNA model that Watson and Circk later used to make their model

How does x-ray crystallography work?

The x-rays deflect as they pass through the crystallized fibers of DNA

How many bonds exists between A and T?

2

How many bonds exist between G and C?

3

How is DNA replication a semi-conservative replication?

Because the strands are complimentary, so one double helix can produce 2 daughter strands

How many nucleotides a second can we replicate?

50

How many nucleotides a second can a bacteria synthesize?

500

What structure represents the specific sequence of DNA that initiates replication?

The Origin of Replication

What is the enzyme that unravels the DNA?

Helicase

What does the unraveling of DNA create?

A replication bubble

What is the y-shaped structure at the start/end of the replication bubble called?

The replication fork

What enzyme relieves tension caused by the helicase?

Topoisomerase

What proteins stabilize the single-stranded DNA to keep them from realigning?

Single-strand binding proteins

What is the nucleic acid sequence of RNA that provides a starting point for DNA synthesis?

Primer

What enzyme synthesizes the primer?

Primase

How long is the primer?

5-10 nucleotides long, which is short

Which enzyme is responsible for adding DNA nucleotides and creating the daughter strand?

DNA Polymerase 3

Which enzyme removes primers and replaces them with DNA?

DNA polymerase 1

What direction do the DNA polymerase 3 and Primase work?

5’ to 3’

What are the two types of daughter strands called?

The leading strand and the lagging strand

How does DNA polymerase act on the leading strand?

It directly follows the helicase

What are the segments called in the lagging strand?

The Okazaki fragments

What does each okazaki fragment have its own of?

A primer that gets replaced by DNA polymerase 1

How are the okazaki fragments sealed together once the primers have been removed?

DNA Ligase

Eukaryotic chromosomes are linear, what does this mean for DNA polymerase?

The 5’ ends can’t be repeated by DNA polymerase, producing shorter chromosomes each replication

How do our chromosomes combat the loss of DNA due to the linear structure of our chromosomes?

Telomase, ends of our chromosomes with no important information

Do the telomeres completely solve the problem of smaller and smaller chromosomes each replication?

No, they can only postpone the inevitable

What happens in transcription?

The DNA template strand becomes mRNA, tRNA, and rRNA

What happens in translation?

the mRNA becomes a 1st degree protein