Genetics Test 1

Question 1

Be able to describe a virus.

Answer 1

Neither prokaryotic nor eukaryotic. There is even debate on whether they are living or not. Cant replicate alone, it needs to infect a cell.

Question 2

Prokryotes

Answer 2

Unicellular
No nucleus
Not membrane bound
Not s much in them
DNA isnt tightly packed
Single circular chromosome

Question 3

Eukaryotes

Answer 3

Yes nucleus
Can be unicellular or multicellular
Multiple linear chromosomes within nucleus (tightly packed around histones)

Question 4

Understand the implications of the fact that all organisms use similar genetic systems.

Answer 4

All living things use similar genetic systems and are constructed from cells

Question 5

When is something a good genetic model

Answer 5

Small, short lived, lots of offspring, genetic similarity, can be mutated

Question 6

Give some examples of how genetics is important in today’s society.

Answer 6

Help affect traits and health
Important in agruculture (selective breeding and GMOs
Medicine
Development, evolution, etc.

Question 6

Nucleic acids

Answer 6

encode the information required for the creation and maintenance of biological creatures.Nucleic acids are polymers of nucleotides.

Question 7

Know the four nitrogenous bases in DNA and which ones are purines vs. pyrimidines (2 vs. 1 ring) and how this determines constant width of the DNA helix

Answer 7

Purines (2) - adenine and guanine
Pyrimidines (1)- thymine and cytosine
Pairs: adenine and thymine; guanine and cytosine

Question 8

antiparallel

Answer 8

antiparallel - they are the same but go in opposite directions

Question 9

DNA replication requirements

Answer 9

• Template must be single stranded
• Raw materials (dNTPs)
• Enzymes need to read template and assemble raw materials

Question 10

Be able to describe all the various steps of DNA synthesis (general)

Answer 10

Initiation, unwinding, elongation, termination

Question 11

initiation

Answer 11

Initiator proteins bind to origin and separate stands of a small section of DNA

Question 12

Unwinding

Answer 12

• DNA Helicase-
  * Unwinds DNA
  *ssDNA binding protein -
  *Keeps the strands separated
  *DNA gyrase -
  Relieives supercoiling

Question 13

List and explain at least 3 differences between prokaryotic and eukaryotic DNA replication.

Answer 13

Single origin in prokaryotic and several in eukaryotic
The gyrase relieves supercoilding of helicase in prokayriotics and the topoisomerase does it in Eukaryotic
Replication is continuous in prokaryotic and based on cell cycle in eukaryotic

Question 14

Binary fission

Answer 14

starts on specific place on circular chromosome (origin of replication). The origins move away from each other and SMC encircle DNA and help chromosomes from getting tangled in replication. Then cell walls form.

Question 15

Cell reproduction in eukaryotes compared to prokaryotes

Answer 15

Similar to prokaryotes but way more complex.

Question 16

Mitosis

Answer 16

single nuclear division. Newly formed cell is identical

Question 17

Meiosis

Answer 17

two divisions, newly formed cell is half

Question 18

Aneuploidy

Answer 18

An increase or decrease in # of individual chromosome

Question 19

types of anueploidy

Answer 19

nullisomy, monosomy, trisomy, tetrasomy

Question 20

Nullisomy

Answer 20

loss of both homologous pairs of chromosomes

Question 21

Monosomy

Answer 21

loss of a single chromosome

Question 22

Trisomy

Answer 22

gain of a single chromosome

Question 22

Tetrasomy

Answer 22

gain of two homologous chromosomes

Question 23

types of polyploidy

Answer 23

autopoloploidy and allopoloploidy

Question 23

polyploidy

Answer 23

presence of more.than 2.setsofchromosomes (common in plants)

Question 24

translocations on phenotype

Answer 24

Nonreciprocal Reciprocal Balanced Unbalanced

Question 25

Understand fragile sites/hot spots.

Answer 25

Sites that are prime to breakage due to replication stress

Question 26

purines: larger or smaller?

Answer 26

larger

Question 27

pyrimadines: larger or smaller?

Answer 27

smaller

Question 28

Sugar how does it look:

Answer 28

pentagon ish looking thing

Question 29

Part in DNA that is a circle w two lines connecting to smaller circles on the edge-

Answer 29

Phospherdiester bond

Question 30

Number of base pairs per turn-

Answer 30

10

Question 31

Number of bonds per base pair

Answer 31

AT=2; GC=3

Question 32

elongation

Answer 32

* Primase - This syntehsises short stretches of RNA nucleotides. * DNA polymerase - DNA polymerase(s) synethsies the leading and lagging strands and removes RNA primers This requires primase to act before because it creates a foundational template for polymerase. It is important to know that it can only add to the 3’ end of DNA. * DNA liagase - DNA liagase takes care of Okazaki fragments by forming phophodiester bonds between them. Since DNA synthesis can only in the 5’ to 3’ direction, this is where ligase comes in to play.

Question 33

monohybrid

Answer 33

cross happening in the F1 generation offspring of parents differing in ONE trait only

Question 34

DNA vs RNA sugar

Answer 34

In DNA, the sugar is deoxyribose, while in RNA, the sugar is ribose.

Question 35

dihybrid

Answer 35

a cross that happens in F1 generation offspring differing in TWO traits

Question 36

Griffith’s experiment

Answer 36

Genetic info was passed from dead to living cells. This was called transforming principle

Question 37

Avery, MacLeod, McCarty

Answer 37

Clear that substance in transforming principle carries genetic info, but what substance carries that info, DNA, RNA, or protein? Result: transforming principle only happened w/DNA present soooo DNA must carry genetic info

Question 38

Hershey-Chase

Answer 38

DNA is the genetic info in bacteriophage (through color labeling and blending. Which does it spread to bacteria in?)

Question 39

Base Pairs:

Answer 39

Adenine + thymine Guanine + cytosine

Question 40

chromatin

Answer 40

DNA + histone proteins. helps package DNA smaller

Question 41

histones

Answer 41

the histones are proteins that help support DNA

Question 42

Euchromatin vs. heterochromatin

Answer 42

Euchromatin * less condensed * found on chromosome arms * has many genes * has unique sequences * often transcription Heterochromatin * tightly condenced * found at centromeres, telomeres, and other specific locations * has few genes * has repeated sequences * infrequent transcription

Question 43

nucleosome

Answer 43

sequence w/eight histones

Question 44

telomeres

Answer 44

A telomere is a region of repetitive DNA sequences at the end of a chromosome. Telomeres protect the ends of chromosomes from becoming frayed or tangled. Each time a cell divides, the telomeres become slightly shorter.

Question 45

Centromere

Answer 45

Where sister chromatids connect (this is where kenetichore is located)

Question 46

chiasmata

Answer 46

a structure that forms between a pair of homologous chromosomes by crossover recombination and physically links the homologous chromosomes during meiosis.

Question 47

when does crossing over happen

Answer 47

prophase 1

Question 48

Autopoloploidy

Answer 48

More than two sets of chromosomes often due to failure of cell division. same parent specific

Question 49

Allopolyploid

Answer 49

more than two sets of chromosomes from two different species (think of a mule)

Question 50

Nonrecombinent

Answer 50

same as parents

Question 51

Recombinant

Answer 51

not same as parents

Question 52

independent assortment

Answer 52

genes are independent of each other (meaning if you get one, you wont necessarily get the other)

Question 53

linked genes

Answer 53

near each other on a chromosome and thus inherited together more often.

Question 54

why are worms ideal for genetic models?

Answer 54

* small (and easy to acquire and manage) * short-lived (makes it easier to study faster) * around 70% genetically similar to humans

Question 55

leading strand

Answer 55

going to be continuous. 5' to 3'.

Question 56

lagging strand

Answer 56

fragments w polymerase. opposite direction as replication fork