Lab Quiz 3

Question 1

Which phase of the M-Phase lasts the longest?

Answer 1

Interphase.

Question 2

What are the different phases of mitosis in order?

Answer 2

Prophase, metaphase, anaphase, telophase.

Question 3

What are the phases of the cell cycle in order? Briefly, what happens in each?

Answer 3

G1 (growth), G0 (function), S-Phase (DNA synthesis), G2 (Preparation for division), M-Phase (Reproduction), Cytokinesis (Cell division).
All are grouped into the Interphase except for the M-Phase and Cytokinesis.

Question 4

What is the duplication of bacteria, mitochondria, and chloroplasts called?

Answer 4

Binary fission.

Question 5

During what phase does the centrosome duplicate?

Answer 5

Gap 2.

Question 6

During what phase do the mitochondria and chloroplasts duplicate?

Answer 6

Gap 2.

Question 7

What happens during prophase?

Answer 7

The nucleoli disappear, the nuclear membrane breaks down, centrosomes migrate to opposite poles, chromosomes start to become visible.

Question 8

What are the stages of meiosis in order? Briefly describe each.

Answer 8

Prophase I: Homologous pairs form. Crossing Over occurs Metaphase I: Homologous pairs line up on metaphase plate. Anaphase I: Homologous pairs are pulled apart. Telophase I: Cells separate into haploid daughter cells.

Prophase II: Chromosomes condense. Metaphase II: Chromosomes line up at the metaphase plate. Anaphase II: Chromatids are pulled apart. Telophase II: 2 haploid cells divide into 4 haploid cells, nuclear membranes reform.

Question 9

When does crossing over occur during meiosis?

Answer 9

During prophase I.

Question 10

What happens during Metaphase in Mitosis?

Answer 10

In Mitosis, metaphase is when chromosomes line up on the metaphase plate.

Question 11

What happens during Metaphase in Meiosis?

Answer 11

In Meiosis, metaphase I is where homologous pairs line up on the metaphase plate. Metaphase II is when sister chromatids line up on the metaphase plate.

Question 12

What happens during Anaphase in Meiosis?

Answer 12

In Meiosis, anaphase I is when homologous pairs are pulled apart. Anaphase II is when sister chromatids are pulled apart.

Question 13

What happens during Anaphase in Mitosis?

Answer 13

In Mitosis, anaphase is when the sister chromatids are pulled apart.

Question 14

What happens during Telophase in Meiosis?

Answer 14

In Meiosis, telophase I is when 2 cells are formed from the first cell. Telophase II is when these 2 cells are further divided into 4 cells.

Both of these phases are marked by the reformation of the nucleus. Nucleoli also start to reappear, sometimes only in Telophase II though.

Question 15

Describe the appearance of all of the M-Phases under the microscope.

Answer 15

Interphase: Nucleoli can be seen.

Prophase: Nucleus becomes darker, chromosomes can start to be seen.

Metaphase: Chromosomes are lined up at the center of the nucleus.

Anaphase: Chromosomes are pulled to opposite poles.

Telophase: 2 nuclei can be seen, the cell is about to divide.

Question 16

What is the region where cells divide in the onion root cell called?

Answer 16

The meristem

Question 17

Why is DNA more susceptible to chemical damage during metaphase and anaphase?

Answer 17

Because the nuclear membrane has broken down.

Question 18

What could be seen in the fish blastodisc cell in metaphase that could not be seen in the onion root cell?

Answer 18

The aster, which are the spindle fibers connecting the centrosome to the plasma membrane.

Question 19

How many degrees of freedom are there if there are 4 possible options?

Answer 19

3 degrees of freedom.

Question 20

What are genotypes and phenotypes?

Answer 20

The Genotype represents the chromosomes or genetic material of a specimen.

The Phenotype is what can be observed. Ex. Red Eyes.

Question 21

What are the two eye colors for fruit flies?

On what gene does the eye color reside?

Which are the dominant and recessive genes?

Answer 21

Red and White.

On the X sex chromosome.

X^w for white eyes is recessive, while X⁺ for red eyes is dominant.

Question 22

If a male Drosphila has white eyes, what is his genotype?

If a male Drosphila has red eyes, what is his genotype?

Answer 22

X^wY

X⁺Y

Question 23

What is the phenotype of a X^wX⁺ Drosphila?

How would we describe this genotype in words?

Answer 23

A X^wX⁺ Drosphila is a red eyed female.

Heterozygote.

Question 24

What is the proper name of the fruit fly?

Answer 24

Drosphila melanogaster

Question 25

What is the genotype of a white eyed female Drosophila? How can this genotype be described in words?

Answer 25

X^wX^w This is homozygote recessive.

Question 26

What is the critical probability value?

Answer 26

5% or 0.05

Question 27

What is the name of the hypothesis we made at the beginning of the lab. Can it be prooved?

Answer 27

The null hypothesis. It can only be rejected or not rejected, never prooved.

Question 28

How many autosomal and sex chromosomes do the fruit flies have?

Answer 28

3 pairs of autosomal and 1 pair of sex chromosomes.

Question 29

Analyze this population and give a hypothesis on the genotype of the parents. Explain. All males have white eyes, all females have red eyes.

Answer 29

Female parent: X^wX^w Male parent: X⁺Y Since all females will have gotten the X⁺ from their father, and the red allele is dominant, all females will have red eyes. In order for all males to have white eyes, they must all have gotten a X^w from their mother. In this case, the mother is Homozygote recessive.

Question 30

What product was used to make the flies fall asleep?

Answer 30

Fly Nap^TM

Question 31

What type of microscope was used to observe the fruit flies?

Answer 31

A stereomicroscope.

Question 32

How are male Drosophila differentiated from females.

Answer 32

Size: Males are smaller than females. Body Color: Men have a black posterior, while females are _usually_ striped. Shape: Men have a more rounded caudal tip to their abdomens than females. **Males have sex combs on front legs, females do not!**

Question 33

What happens when the probability is 5%?

Answer 33

The null hypothesis is rejected.

Question 34

On which segment of the male Drosophila's leg is the sex comb located?

Answer 34

Tarsi I.

Question 35

Approximately how long was the male Drosphila leg

Answer 35

1.25 mm

Question 36

What are the components of the Drossophila Larva? Describe each briefly

Answer 36

Posterior Spiracles: end of trachea sticking out of the back Trachea: Two long tubes that go from head to tail. Mouth Parts: hooks where the mouth is. Body Segments: 11 little lumps on the side of the larva. Salivary Glands: Two big patches behind the mouth.