Exam 3

A diploid cell has_______ the number of chromosomes & a haploid cell has _______ the number of chromosomes

two sets / one set

An organism’s traits are determined by the specific combination of inherited _____.

genes

Identical copies of chromatin held together by cohesin at the centromere are called _____.

sister chromatids

The four major stages in order during mitosis are:

prophase, metaphase, anaphase, telophase

At which of the cell-cycle checkpoints do external forces have the greatest influence?

G1 checkpoint

Many of the negative regulator proteins of the cell cycle were discovered in what type of cells?

cancer cells

The mitotic spindles arise from which cell structure?

centrosome

Which of the following events does not occur during some stages of interphase?

separation of sister chromatids

A gene that codes for a positive cell-cycle regulator is called a(n) _____.

proto-oncogene

Which eukaryotic cell-cycle event is missing in binary fission?

karyokinesis

Define the Diaphysis of a long bone.

The shaft (central elongated body) of the bone

Define the Epiphysis and Metaphysis of a long bone.

The ends of the bones

What and where is the Medullary Cavity

The hollow area inside inside the diaphysis (shaft) of a long bone

Where exactly is red bone marrow located in a long bone, and what does it do?

In the epiphysis/metaphysis (ends); it produces blood cells

Where is the yellow bone marrow located and what is the function

In the medullary cavity (shaft); it acts as a reservoir for fat/lipids (energy storage)

Which 5 body regions do human long bones orginate

arms, legs, hands, feet, and the clavicles

endochondral ossification

The embryonic process where cartilage templates are gradually replaced by bone tissue to form long bones

total vertebrae in the human spine, what shape do they form?

33, they form a natural S- shaped curve from the side view

Name the Cervical region location and its exact number of vertebrae.

neck; 7 vertabrae

Name the Thoracic region location and its exact number of vertebrae.

mid back ; 12 vertebrae

the Lumbar region location and number of vertebrae

lower back; 5 vertebrae

the Sacral region of the spine and bone count

5 fused vertebrae located below the lumber spine

The Coccygeal region of the spine and bone count

3-4 fused vertebrae forming the tailbone

Attachment of the mitotic spindle fibers to the kinetochores is a characteristic of which stage of mitosis

prometaphase

Unpacking of chromosomes and the formation of a new nuclear envelope is a characteristic of which stage of mitosis?

telophase

Separation of the sister chromatids is a characteristic of which stage of mitosis?

anaphase

The chromosomes become visible under a light microscope during which stage of mitosis

prophase

The fusing of Golgi vesicles at the metaphase plate of dividing plant cells forms what structure?

cell plate

order of events in mitosis

The kinetochore becomes attached to the mitotic spindle. Sister chromatids line up at the metaphase plate. Cohesin proteins break down and the sister chromatids separate. The nucleus reforms and the cell divides.

What is the main prerequisite for clearance at the G2 checkpoint?

accurate and complete DNA replication

If the M checkpoint is not cleared, what stage of mitosis will be blocked?

anaphaseWhich protein is a positive regulator that phosphorylates other proteins when activated?

Which protein is a positive regulator that phosphorylates other proteins when activated?

cyclin-dependent kinase (Cdk)

Which negative regulatory molecule can trigger cell suicide (apoptosis) if vital cell cycle events do not occur?

p53

___________ are changes to the order of nucleotides in a segment of DNA that codes for a protein.

gene mutations

A mutated gene that codes for an altered version of Cdk that is active in the absence of cyclin is a(n) _____.

oncogene

Which molecule is a Cdk inhibitor that is controlled by p53

p21

FtsZ proteins direct the formation of a _______ that will eventually form the new cell walls of the daughter cells

septum

Mendel performed hybridizations by transferring pollen from the _______ of the male plant to the female ova.

anther

Which is one of the seven characteristics that Mendel observed in pea plants

seed texture

Imagine you are performing a cross involving seed color in garden pea plants. What F1 offspring would you expect if you cross truebreeding parents with green seeds and yellow seeds? Yellow seed color is dominant over green

100 yellow seeds

Consider a cross to investigate the pea pod texture trait, involving constricted or inflated pods. Mendel found that the traits behave according to a dominant/recessive pattern in which inflated pods were dominant. If you performed this cross and obtained 650 inflated pod plants in the F2 generation, approximately how many constricted-pod plants would you expect to have?

217

A scientist pollinates a true-breeding pea plant with violet, terminal flowers with pollen from a true-breeding pea plant with white, axial flowers. Which of the following observations would most accurately describe the F2 generation

75 violet, 75 axial

The observable traits expressed by an organism are described as its ________.

phenotype

A recessive trait will be observed in individuals that are ________ for that trait

homozygus

If black and white true-breeding mice are mated and the result is all gray offspring, what inheritance pattern would this be indicative of?

incomplete dominance

Therefore, ABO blood groups are an example of

multiple alleles and codominance

In a mating between two individuals that are heterozygous for a recessive lethal allele that is expressed in utero, what genotypic ratio do you expect to observe in the offspring

1:2:0

If the allele encoding polydactyly (six fingers) is dominant, why do most people have five fingers?

The polydactyl allele is very rare in the human population.

A farmer raises black and white chickens. When the first generation of eggs hatch, all the chickens are black with white speckles throughout their feathers. What should the farmer expect when the eggs laid after interbreeding the speckled chickens hatch?

50 mix, 25, black, 25 white

Assuming no gene linkage, in a dihybrid cross of AABB x aabb with AaBb F1 heterozygotes, what is the ratio of the F1 gametes (AB, aB, Ab, ab) that will give rise to the F2 offspring

1:1:1:1

The forked line and probability methods make use of what probability rule?

product rule

How many different offspring genotypes are expected in a trihybrid cross between parents heterozygous for all three traits when the traits behave in a dominant and recessive pattern? How many phenotypes?

27 genotypes; 8 phenotypes

Labrador retrievers’ fur color is controlled by two alleles, E and B. Any dog with the ee__ genotype develops into a yellow lab, while B_E_ dogs become black labs and bbE_ dogs become chocolate labs. This is an example of _____.

epistasis

Which of the following situations does not follow the Law of Independent Assortment

Men are more likely to experience hemophilia than women.

X-linked recessive traits in humans (in Drosophila) are observed

in more males than females

The first suggestion that chromosomes may physically exchange segments came from the microscopic identification of

chiasmata

Which recombination frequency corresponds to independent assortment and the absence of linkage

.50 a recombination of 50% is the max possible

Which recombination frequency corresponds to perfect linkage and violates the law of independent assortment?

0: 2 genes are never separated by a crossover event, (travel 100% together)

Which of the following codes describes position 12 on the long arm of chromosome 13?

13q12

q=

long arm

p=

short arm

in agriculture, polyploid crops (like coffee, strawberries, or bananas) tend to produce

larger yields

Assume a pericentric inversion occurred in one of two homologs prior to meiosis. The other homolog remains normal. During meiosis, what structure—if any—would these homologs assume in order to pair accurately along their lengths?

they must bend into a loop

The genotype XXY corresponds to

Klinefelter syndrome

Abnormalities in the number of X chromosomes tends to have milder phenotypic effects than the same abnormalities in autosomes because of .

X inactivation

By definition, a pericentric inversion includes the .

centromere

Which scientific concept did Charles Darwin and Alfred Wallace independently discover

natural selection

Natural selection requires

resource competition, physical variation, and uneven reproductive success. out preforming others

example of a phenotype

any observable trait of an organism

Convergent evolution

when unrelated species independently evolve similar traits