exam 1

Question 1

You work in a lab. You engineer a mutant mouse that doesn’t synthesize a protein important for breakdown of the sugar galactose and study the results. What type of geneticist are you?

Answer 1

Molecular geneticist

Question 2

Which of the following could be used to study the effects of drugs on gene expression?

Answer 2

molecular genetics

Question 3

A cellular structure that contains genetic information is called a ___________.

Answer 3

chromosome

Question 4

_______ is the use of the information in gene sequences to synthesize functional proteins that affect cellular characteristics.

Answer 4

Gene expression

Question 5

Which one of the following is NOT one of the general classes of macromolecules that are necessary for cellular function?

Answer 5

ions

Question 6

Genetic variation is ultimately based upon which of the following?

Answer 6

variations in nucleotide sequence of the DNA

Question 7

Ball pythons of the same species can look very different from one another. In fact, there are at least 26 types of ball pythons, characterized by their color, eyes, and markings. The blue-eyed leucistic ball python has blue eyes and white scales. The bumblebee ball python has black and yellow scales. The coral glow ball python has purple and orange scales. What term best describes these different types of pythons?

Answer 7

Morphs

Question 8

Chronic myelogenous leukemia cells are characterized by the so-called Philadelphia chromosome, which contains part of chromosome 22 fused with chromosome 9. The Philadelphia chromosome is the result of a translocation, in which two chromosomes exchange material. The genetic variation found in chronic myelogenous leukemia is therefore due to

Answer 8

major alterations in the structure of a chromosome.

Question 9

What is the first step that both scientists and students perform to answer questions in genetics?

Answer 9

Gathering background information

Question 10

Genetics is an experimental, as opposed to theoretical, science because ______.

Answer 10

hypotheses are tested by performing experiments

Question 11

Which of the following would contain genetic material that is 100% identical?

Answer 11

sister chromatids

Question 12

During this phase of the cell cycle, the sister chromatids are formed in eukaryotes.

Answer 12

S phase

Question 13

A cytogeneticist would primarily do which of the following?

Answer 13

examine chromosomes using a karyotype

Question 14

The location of a gene on a chromosome is called its _____________.

Answer 14

locus

Question 15

The process of meiosis II is similar to that of __________.

Answer 15

mitosis

Question 16

A species has a diploid number of 36. If meiosis didn’t occur, and gametes were produced by mitosis, each gamete would contain ______ chromosomes, and a fertilized egg would contain ______ chromosome.

Answer 16

36; 72

Question 17

Select the phase when the chromosomes line up in the center of the cell.

Answer 17

Metaphase

Question 18

Cytokinesis in animals occurs through the formation of a ______, whereas in plants a ______ forms.

Answer 18

cleavage furrow; cell plate

Question 19

A pollen grain in a plant represents the ________.

Answer 19

male gametophyte

Question 20

Oogenesis is a gametogenic process in which cells undergo ________ to produce _______.

Answer 20

meiosis; egg cells

Question 21

What aspect of meiosis best explains Mendel’s law of independent assortment?

Answer 21

random alignment of different bivalents during Meiosis I

Question 22

Which situation below would violate the law of independent assortment, as understood by Mendel?

Answer 22

A gene for leaf shape is linked to a gene for petal number nearby on the same chromosome, so their alleles usually segregate together.

Question 23

Mendel’s law of independent assortment states that ______ randomly assort their ______ during the formation of haploid cells.

Answer 23

genes; alleles

Question 24

An individual who has two identical alleles for a trait is said to be ___________.

Answer 24

homozygous

Question 25

The genetic composition of an individual is called its _____________.

Answer 25

genotype

Question 26

If over several generations a character does not vary in a group of organisms, that group can be called a _______.

Answer 26

true-breeding line

Question 27

Which of the following characteristics made the pea plant Pisum sativum an ideal organism for Mendel's studies?

Answer 27

It has the ability to self-fertilize. It was possible to cross-fertilize one plant with another. It has easily identifiable traits.

Question 28

Recall that in pea plants, purple flower color is dominant and white is recessive. If two heterozygous plants are crossed, what is the probability that the first two offspring will have purple flowers?

Answer 28

9/16

Question 29

The chance that a future event will occur is called ____________.

Answer 29

probability

Question 30

In humans, patterns of inheritance are often studied using which of the following?

Answer 30

pedigree analysis

Question 31

Who originally identified a highly condensed structure in the interphase of nuclei?

Answer 31

Barr and Bertram

Question 32

What gene is most responsible for X-inactivation?

Answer 32

Xist

Question 33

Dosage compensation offsets the problems associated with differences in the number of _______ chromosomes in many species.

Answer 33

sex

Question 34

An example of a mechanism in which sex is determined by environmental factors is

Answer 34

fertilized eggs incubated at one temperature produce males, whereas eggs incubated at a different temperature produce females.

Question 35

Sex determination in humans and Drosophila is similar in the fact that

Answer 35

males have one X chromosome and females have two X chromosomes.

Question 36

A male that is produced from an unfertilized haploid egg is an example of what type of sex determination system?

Answer 36

haplo-diploid

Question 37

If a gene is located on the X chromosome, but not the Y, it is said to be an example of ________.

Answer 37

sex-linkage

Question 38

Brown spotting of the teeth in humans is caused by a dominant X-linked gene. If a man with normal teeth marries a woman with brown teeth who had a father with normal teeth, then _______ of their daughters will have brown teeth.

Answer 38

50%

Question 39

Glucose-6-phosphate dehydrogenase deficiency (G6PDD) is an X-linked recessive disease. What is the probability that the brother of a girl with G6PDD will also have G6PDD if their mother is unaffected.

Answer 39

50%

Question 40

The first person to experimentally determine that a trait is located on a specific chromosome was ____________.

Answer 40

Morgan

Question 41

If a geneticist describes a trait as being 70% penetrant, what would that mean?

Answer 41

Only 70% of the individuals who have a particular genotype express the trait.

Question 42

An experiment in which plants with the same genotype are raised under conditions that differ in soil quality could evaluate _____.

Answer 42

the norm of reaction

Question 43

If a combination of two or more genes is required to produce a specific trait, it is called a(n) _______.

Answer 43

gene interaction

Question 44

Epistasis occurs when the alleles of one gene mask the phenotypic effects of the alleles of another gene at a different locus. This phenomenon can be observed in the sweet pea, Lathyrus odoratus: C (one purple-color-producing) allele is dominant to c (white) P (another purple-color-producing) allele is dominant to p (white) cc or pp masks the P or C alleles, producing white color Determine the genotypic and phenotypic ratios of a cross between a purple and white sweet pea above.

Answer 44

1 CcPP (purple) : 1 CcPp (purple) : 1 ccPP (white) : 1 ccPp (white)

Question 45

In overdominance, the _______ genotype is beneficial over the _______ genotypes.

Answer 45

heterozygous; homozygous

Question 46

At the molecular level, type A and type B blood differ in which of the following characteristics?

Answer 46

the antigens present on the surface of the red blood cells the type of sugar found in each type the antibodies that are generated against the other type of blood

Question 47

The alleles that cause Huntington disease in humans are an example of ____________.

Answer 47

lethal alleles

Question 48

In rabbits, full coat color (C  ) is the dominant trait. A second allele, chinchilla (c ch ), is recessive to full coat color. Himalayan coat color (c h ) is recessive to chinchilla and full coat colors, and albino (c ) is recessive to all coat colors. If two chinchilla rabbits mate, what coat color is not possible in their offspring?

Answer 48

full coat color

Question 49

If an allele is dominant in one sex and recessive in another, it is an example of ___________.

Answer 49

sex-influenced inheritance

Question 50

The multiple effects of a single gene on the phenotype of an organism is called _______.

Answer 50

pleiotropy

Question 51

What disease is associated with imprinting?

Answer 51

Angelman Syndrome

Question 52

What is the type of inheritance that is based on a reversible modification of genomic DNA that results in the alleles of only one parent being transcriptionally active?

Answer 52

epigenetic

Question 53

How is a chloroplast genome similar to a prokaryotic genome?

Answer 53

They are both circular.

Question 54

What type of inheritance is observed with extranuclear DNA?

Answer 54

Cytoplasmic inheritance

Question 55

Contribution of mitochondria by the sperm cell to the zygote is called

Answer 55

paternal leakage.

Question 56

Diseases associated with mitochondria mutations in humans are usually

Answer 56

degenerative.

Question 57

Which of the following is primarily responsible for the maternal effect?

Answer 57

nurse cells

Question 58

If a snail that has a right hand twist and is DD is mated to a snail that has a left hand twist and is dd what is the expected ratio of progeny?

Answer 58

It depends on which parent snail is female and which is male.

Question 59

The symbiotic relationship where one organism lives inside another species is called

Answer 59

endosymbiosis.

Question 60

Mitochondria are thought to have originated from ______, and chloroplasts likely arose from ______.

Answer 60

purple bacteria; cyanobacteria