Chapter 11-16 study guide

Question 1

Asexual reproduction

Answer 1

The offspring is genetically identical to the parent

Question 2

Sexual reproduction

Answer 2

The offspring is genetically different from its parents

Question 3

True breeding

Answer 3

The observed trait was the only form present in many generations

Question 4

Monohybrid crosses

Answer 4

Mendels first experiment he found that it is segregation of alleles. F1 generation

Question 5

independent assortment

Answer 5

the genes do not mix they are separate the genes do not mix

Question 6

Segregation

Answer 6

when any individual produces gametes the two copies of the gene separate so that each gamete receives one copy.

Question 7

Dihybrid cross

Answer 7

mendel disscoved this with the f2 generation he discovered independent assortment.

Question 8

Complete dominance:

Answer 8

A kind of dominance wherein the dominant allele completely masks the effect of the recessive allele in heterozygous condition.

Question 9

Incomplete dominance

Answer 9

Incomplete dominance is a form of intermediate inheritance in which one allele for a specific trait is not completely dominant over the other allele. This results in a combined phenotype.Red flower with white flower is a pink flower.

Question 10

Codominance

Answer 10

It occurs when the contributors of both alleles (genes) are clearly visible and do not overpower each other in the phenotype

Question 11

Pleiotropy

Answer 11

When a single allele has more than one distinguishable phenotypic effect.

Question 12

Epistasis

Answer 12

The phenotypic expression of one gene that is affected by another gene.

Question 13

Penetrance

Answer 13

Is the proportion of individuals in a group with a given genotype that actually show the expected phenotype.

Question 14

Expressivity

Answer 14

The degree to which a genotype is express in an individual

Question 15

Why are some phenotypes complex

Answer 15

The environment is affected by the environment, the phenotype is determined by multiple genes.

Question 16

how are the genes in mitochondria and chloroplast different from nuclear genes

Answer 16

They are different because they tend to mutate at a much faster rate, Nuclear genes you inherit from mother and father, In mitochondria and chloroplast you only inherit from your mother. There may be hundreds of mitochondria or chloroplasts in a cell is not diploid for an organelle gene.

Question 17

DNA structure

Answer 17

Double helix Deoxyribonucleic acid, Sugar deoxyribose, a phosphate group, and nitrogen containg base, bases are GCAT. Antiparallel,Nucelotide bases are on the interior while sugar phosphate is on the outside. Base pairs have the same width down the double helix. They are also right handed.

Question 18

Franklin:

Answer 18

X-ray crystallography. To say that DNA is spiral and helical.

Question 19

Crick and Watson

Answer 19

Assembled three-dimension representations. They used known bond angles, and relative molecular dimension. They combined all known info on DNA. There are two polynucleotide chains in the molecule, the nitrogenous bases are interior to two strands =m the phosphate sugar backboard is towards the outside,

Question 20

Griffith

Answer 20

Studied streptococcus pneumonia, demonstrated the phenomenon of bacterial transformation.

Question 21

Meselson-Stahl

Answer 21

They found the semi conservative model. (One Dna strand is New the other strand is an existing strand.)

Question 22

Telomeres

Answer 22

They are repetitive DNA sequence at the end of eukaryotic cells., They DNA repair system from recognizing the ends.

Question 23

How are telomers replicated?

Answer 23

It uses an enzyme called telomerase, and it catalyzes the addition of any lost telomeric sequences in these cells. Telomerase contains an RNA sequence that acts as template for the telomeric DNA repeat sequence.

Question 24

Okazaki fragments

Answer 24

The lagging strand, new stretches of DNA with gaps, requires multiple rimers after each gap. DNA polymerase 3 synthesizes an okanzaki fragment by adding nucleotides to one primer until it reaches the primer of the previous fragment. DNA polymerase 1 removes the old primer and replaces it with DNA. Leaving behind a tiny nick. The enzyme DNA ligase links the fragments making the lagging strand whole.

Question 25

How many DNA repair mechanisms do cells have and what are they?

Answer 25

Proofreading,mismatch repair, and excision repair.

Question 26

Proofreading

Answer 26

DNA polymerase perform it and each time they introduce a new nucleotide in a growing DNA strand. When it recognizes a mispairing of bases, it removes the improperly introduced nucleotide and tries again.

Question 27

Mismatch base repair

Answer 27

A mechanism that scans DNA after it has been replicated and corrects it. Takes out the mismatched base and adjacent based then DNA polymerase fixes its.

Question 28

Excision repair

Answer 28

emoves abnormal bases that have formed because of chemical damage and replaces them with functional bases.

Question 29

PCR

Answer 29

polymerase chain reaction, Amplifies specific DNA sequences, it is separated by heating and the best way for determining the identity of a drop of blood is using PCR.

Question 30

RNA different from DNA:

Answer 30

1) RNA consists of only of one polynucleotide strand, the sugar in RNA is ribose, the nitrogenous bases is the same of DNA except for thymine RNA is uricil it lacks a CH3 group.

Question 31

Beadle and Tatum

Answer 31

They had several mutant strains of neurospora that could not make argine so they place spores of each arg mutant strain on a minimal nutritional medium with and supplements. They concluded that each gene specifies a particular enzyme. Modern definition is each gene is a polypeptide.

Question 32

Central dogma

Answer 32

DNA to RNA to polypeptide.

Question 33

Aminacyle-tRNA synthetases

Answer 33

The charging of each tRNA with its correct amino acid works by enzymes called Aminoacyly-tRNA synthetases, that enzyme has 3 active sites which recognizes 3 molecules one a specific amino acid, atp, and a specific tRNA.

Question 34

DNA to RNA

Answer 34

3’CGG5’- 5’GCC3’ and tRNA anticodon 3’CGG5’ CTA

Question 35

Somatic mutation

Answer 35

mutations occurring in somatic cells.

Question 36

Germ line mutation

Answer 36

mutations that occur in the germ line,like sex cells.

Question 37

Silent mutations

Answer 37

do not affect protein function.

Question 38

Loss of function mutations

Answer 38

affect prtein function, may lead to nonfunctional proteins.

Question 39

Gain of function mutation

Answer 39

leads to a protein with an altered function

Question 40

Conditional mutations:

Answer 40

these are mutations that the environment effects protein function

Question 41

Point mutation

Answer 41

gain,loss, or substitution of a single nucleotide.

Question 42

Chromosomal mutations

Answer 42

change the polisition of a DNA segment.

Question 43

Missense mutations

Answer 43

base subsitituins change the genetic code such that one amino acid subsititues for another in a protein.

Question 44

Nonsense mutations

Answer 44

involves a base subsitituin that causes a stop codon to form somewhere in the mRNA, results in a shortened protein.

Question 45

Deletions in chromosomal mutations

Answer 45

removal of part of the genetic material

Question 46

Duplications

Answer 46

would arise if homolous chromosomes broke at different positions and then reconnected to the wrong partners.

Question 47

Inversions

Answer 47

a segment of DNA may be removed and reinserted into the same location in the chromosome.

Question 48

Translocations

Answer 48

when a segment of a chromosome breaks off and is inserted into a different chromosome.

Question 49

Spontaneous mutations

Answer 49

occur simply because cellular processes are imperfect.

Question 50

Induced mutations

Answer 50

an agent from outside the cell causes permanent change in DNA.