exam 5

Question 1

how can you tell if a pedigree is sex linked?

Answer 1

if males and females aren’t affected equally
x linked dom - more females
x linked rec - more males
y linked - every male, every generation

Question 2

What is Sutton’s Chromosomal Theory of Inheritance?

Answer 2

mendelian genes have specific loci on chromosomes
chromosomes undergo segregation and independent assortment

Question 3

What is genetic linkage?

Answer 3

genes located near each other on the same chromosome that tend to be inherited together - less than 50% recombination frequency

Question 4

What is homologous recombination (crossing over)?

Answer 4

In meiosis I homologous chromosomes swap chunks resulting in new combinations in offspring - the closer genes are, the less likely they are to cross over, so they’re more likely to be inherited together

Question 5

What is nondisjunction and how can it lead to disorders in chromosome number?

Answer 5

Failure of chromosomes to separate from each other - leads to aneuploidy (incorrect number of chromosomes)

Question 6

What are the disorders that aneuploidy causes?

Answer 6

monosomy (2n-1)
trisomy (2n+1)

Question 7

What are some of the errors in chromosome structure?

Answer 7

deletion - removing a chromosome segment
duplication - repeats a segment
inversions - reverses orientation of a segment within a chromosome
translocation - moves a segment from one chromosome to another

Question 8

What are Chargaff’s rules?

Answer 8

base pairing (A+C=G+T)

Question 9

What is the main structure of DNA?

Answer 9

antiparallel, phosphate and deoxyribose sugar backbone, double stranded

Question 10

What is polymerase chain reaction (PCR)?

Answer 10

method to replicate a specific target sequence in DNA, uses heat, includes DNA pol, primers and nucleotides

Question 11

What are the main differences between eukaryotic and prokaryotic DNA?

Answer 11

eukaryotic is linear
Prokaryotic is circular

Question 12

How does the structure of DNA reveal its replication process?

Answer 12

It is semiconservative - two strands come apart and act as a template for the synthesis of a new complementary strand - leading and lagging strand

Question 13

What is the process of DNA replication in prokaryotes?

Answer 13

Replication fork, origin of replication, leading and lagging strands, Okazaki fragments

Question 14

What are the 7 different proteins that help with DNA replication?

Answer 14

Topoisomerase - stress reducer
helicase - unzipping
Single Stranded Binding Protein (SSBP) - stress reducer
Primase - RNA primer
DNA Pol III - synthesize new DNA
DNA Pol I - remove RNA primer and adds DNA
ligase - glues the fragments together

Question 15

What are the roles of telomerase in DNA replication?

Answer 15

it lengthens the telomeres (buffer zone)

Question 16

What are the different types of mutations in DNA?

Answer 16

point - silent, missense (wrong amino acid), nonsense (premature stop)
frameshift - insertion + deletion, alters the reading frame

Question 17

What are some DNA repair mechanisms?

Answer 17

Proofreading - DNA polymerase finds and corrects errors during replication
mismatch repair - one base pair is wrong - fixed by protein
nucleotide excision repair - repairs thymine dimer (nuclease removes, DNA pol synthesizes new DNA, DNA ligase seals it in)

Question 18

What is the central dogma of protein synthesis?

Answer 18

DNA to transcription to mRNA to translation to protein

Question 19

How to nucleotides prescribe the amino acid and proteins?

Answer 19

Codons on the mRNA code for specific acids that create polypeptide chains that make proteins

Question 20

What are the steps of transcription?

Answer 20

Initiation - DNA unwinds, RNA pol attaches to promoter
Elongation - RNA pol aided by transcription factors; RNA made; DNA rewound
Termination - RNA reaches poly a signal or terminator sequence and falls off

Question 21

What is the role of RNA polymerases?

Answer 21

makes a complimentary mRNA copy from DNA template strands and add to 3’ end

Question 22

What is the significance of transcription factors?

Answer 22

They help create mRNA

Question 23

What are the steps in RNA processing?

Answer 23

5’ cap and 3’ poly A tail

Question 24

What is RNA splicing?

Answer 24

Cutting out introns (noncoding regions) and keeps the introns (coding regions)

Question 25

What are the different steps in protein synthesis?

Answer 25

Initiation - small subunit and met tRNA bind to mRNA, large subunit attaches, process takes energy
Elongation - A site, peptide bond, move to P site, empty tRNA exists at E site
Termination - mRNA translate a stop codon, release factor are proteins that bind the stop codon (not tRNA and not an amino acid)

Question 26

What are the roles of ribosomes in protein synthesis?

Answer 26

A site, P site, E site,