from quizlet

Question 1

Polymorphic gene

Answer 1

if more than one allele occupies that gene’s locus within a population
( In addition to having more than one allele at a specific locus, each allele must also occur in the population at a rate of at least 1% to generally be considered polymorphic.)

Question 2

2 trait cross; used to determine if an individual is homozygous dominant or heterozygous for either of the 2 traits by crossing with a homozygous recessive individual

Answer 2

dihybrid test cross

Question 3

linkage group

Answer 3

several genes linked together

Question 4

incompletely dominant or semidominant

Answer 4

heterozygotes having different trait (colour) due to only having half the number of functional genes (proteins)

Question 5

allelic series

Answer 5

alleles are placed in order of the severity of their corresponding phenotype

Question 6

penetrance

Answer 6

phenotype is all-or-none and individuals with the same genotype don’t always show the expected phenotype (percentage)

Question 7

multiple genes that contribute to a trait (genes that affect risk of heart attack)

Answer 7

multiple genes that contribute to a trait (genes that affect risk of heart attack)

Question 8

epistasis

Answer 8

genes interacting in complex ways (coat colour in mice)

Question 9

helicase

Answer 9

enzyme that expends energy to unwind DNA

Question 10

Primase

Answer 10

enzyme that adds a short stretch of complementary RNA (primer) which acts as a ragged end so the DNA polymerase (DNA polymerase III) can go to work

Question 11

DNA polymerase I

Answer 11

chews up the DNA primers and uses the newly synthesized DNA as a primer, fills in the gap, participates in the process of prokaryotic DNA replication

Question 12

DNA polymerase III

Answer 12

duplication of the chromosomal DNA

Question 13

how the cell deals with mistakes made by polymerases (3)

Answer 13

1. polymerase has a proofreading mechanism that immediately removes bases that are not complementary to the template strand 2. there is mechanism at work during recombination called mismatch repair 3. there is a mechanism at work the rest of the time called excision repair (
   locates and repairs incorrect sequence by removing a segment of the DNA and then adding the correct nucleotides, works on thymine dimers formed by exposure to UV light)

Question 14

protein synthesis

Answer 14

made by ribosomes, which are in the cytoplasm of eukaryotes

Question 15

amount of base pairs of DNA in humans

Answer 15

3 million

Question 16

gene

Answer 16

constitute of 2 strands of DNA that have different sequences (the reverse complement of each other)

Question 17

2 strategies of survival of phage

Answer 17

virulent phage (undergoes a lytic reproductive cycle) and temperate phage (undergoes a lysogenic reproductive cycle)

Question 18

retroviruses

Answer 18

similar to lysogenic phage; they bend the rules of the central dogma by making a DNA copy from an RNA genome; the DNA copy of the retrovirus can be integrated into the host chromosome and remain there, inactive, for a long time before it starts producing viral particles again

Question 19

bacteria exchanging genetic material

Answer 19

in the form of bacterial sex; bacteria have mutations that confer phenotypes that you can score (identify); mostly auxotrophic phenotypes

Question 20

auxotrophic genotypes

Answer 20

bacteria that can only grow when certain substances are added to their media, like the Beadle and Tatum experiments with Neurospora

Question 21

specialized transduction

Answer 21

when a prophage excises itself from the chromosome, it can be sloppy and pick up a gene from the bacterial chromosome; the bacterial gene becomes part of the virus genome and will be inserted into the chromosome of another bacteria when infected by that phage

Question 22

generalized transduction

Answer 22

sometimes the phage do a poor job of chopping up the bacterial DNA and instead of packaging phage DNA into the virions, they package chinks of bacterial chromosome; when those virions infect another bacterium, the chunk of bacterial DNA gets injected into the infected bacterium and can be incorporated into the chromosome; since adjacent genes are more likely to be transferred together, generalized transduction can be used to map genes

Question 23

transformation

(Bacteria

Answer 23

bacteria can sometimes take up naked DNA floating around in their environment as shown by Griffith; the genomic DNa can then be integrated by recombination; there is a type of non-genomic DNA called plasmids

Question 24

what is added to the 5’ end in processing

Answer 24

a special methylated guanosine cap - helps translation and RNA stability

Question 25

Matrix or stroma (for plants)

Answer 25

space enclosed by the inner membrane in mitochondria/chloroplast; where you find DNA, RNA, and ribosomes