Fine spines (s), smooth fruit (tu), and uniform fruit color (u) are three recessive traits in cucumbers whose genes are linked on the same chromosome. A cucumber plant heterozygous for all three traits is used in a testcross. The progeny from this testcross are:S U Tu 2
s u Tu 70
S u Tu 21
s u tu 4
S U tu 82
s U tu 21
s U Tu 13
S u tu 17__
Total 230
a. Determine the order of these genes on the chromosome.
b. Calculate the map distances between the genes.
c. Determine the coefficient of coincidence and the interference among these genes.
d. Draw the chromosomes of the parents used in the testcross.

Answers

Answer 1
Answer:

Answer and Explanation:

We have the number of descendants of each phenotype product of the tri-hybrid cross.

  • S U Tu 2
  • s u Tu 70
  • S u Tu 21
  • s u tu 4
  • S U tu 82
  • s U tu 21
  • s U Tu 13
  • S u tu 17

The total number, N, of individuals is 230.

In a tri-hybrid cross, it can occur that the three genes assort independently or that two of them are linked and the thrid not, or that the three genes are linked. In this example, in particular, the three genes are linked on the same chromosome.

Knowing that the genes are linked, we can calculate genetic distances between them. First, we need to know their order in the chromosome, and to do so, we need to compare the genotypes of the parental gametes with the ones of the double recombinants. We can recognize the parental gametes in the descendants because their phenotypes are the most frequent, while the double recombinants are the less frequent. So:

Parental)

  • s u TU (70 individuals)
  • S U tu (82 individuals)

Double recombinant)

  • S U Tu (2 individuals)
  • s u tu (4 individuals)

Comparing them we will realize that between

s u TU (parental)

s u tu (double recombinant)

and

S U tu (Parental)

S U TU (double recombinant)

They only change in the position of the alleles TU/tu. This suggests that the position of the gene TU is in the middle of the other two genes, S and U, because in a double recombinant only the central gene changes position in the chromatid.

So, the order of the genes is:

---- S ---- TU -----U ----

In a scheme it would be like:

Chromosome 1:

---s---TU---u--- (Parental chromatid)

---s---tu---u--- (Double Recombinant chromatid)

Chromosome 2

---S---tu---U--- (Parental chromatid)

---S---TU---U--- (Double Recombinant chromatid)

Now we will call Region I to the area between S and TU and Region II to the area between TU and U.

Once established the order of the genes we can calculate distances between them, and we will do it from the central gene to the genes on each side. First We will calculate the recombination frequencies, and we will do it by region. We will call P1 to the recombination frequency between S and TU genes, and P2 to the recombination frequency between TU and U.

P1 = (R + DR) / N

P2 = (R + DR)/ N

Where: R is the number of recombinants in each region, DR is the number of double recombinants in each region, and N is the total number of individuals.  So:

  • P1 = (R + DR) / N

        P1 = (21+17+4+2)/230

        P1 = 44/230

        P1 = 0.191

  • P2= = (R + DR) / N

        P2 = (21+13+4+2)/230

        P1 = 40/230

        P1 = 0.174

Now, to calculate the recombination frequency between the two extreme genes, S and U, we can just perform addition or a sum:

P1 + P2= Pt

0.191 + 0.174 = Pt

0.365=Pt

The genetic distance will result from multiplying that frequency by 100 and expressing it in map units (MU). One centiMorgan (cM) equals one map unit (MU).

The map unit is the distance between the pair of genes for which one of every 100 meiotic products results in a recombinant product. Now we must multiply each recombination frequency by 100 to get the genetic distance in map units:

GD1= P1 x 100 = 0.191 x 100 = 19.1 MU

GD2= P2 x 100 = 0.174 x 100 = 17.4 MU

GD3=Pt x 100 = 0.365 x 100 = 36.5 MU

To calculate the coefficient of coincidence, CC, we must use the next formula:

CC= observed double recombinant frequency/expected double recombinant frequency

Note:

  • observed double recombinant frequency=total number of observed double recombinant individuals/total number of individuals
  • expected double recombinant frequency: recombination frequency in region I x recombination frequency in region II.

CC= ((2 + 4)/230)/0.174x0.191

CC=(6/230)/0.0332

CC=0.7857

The coefficient of interference, I, is complementary with CC.

I = 1 - CC

I = 1 - 0.7857

I = 0.2143            


Related Questions

What will be the consequence if humans continue to over-hunt elephants for their ivory
1) For each of the genotypes below determine what the phenotype would be. Bobtails in cats are recessive. Normal tails are dominant. TT _____________ Tt _________ tt _____________
For a molecule to be considered organic what elements must be present? A. Carbon only B. Oxygen and hydrogen C. Carbon and hydrogen D. Carbon and oxygen
1. What purpose does the regulatory portion of the gene have? 2. In this simulation, the DNA molecule’s different strands are represented as different colors one blue and one red. What is the significance of the two different strands? Are they both used in transcription? 3. There are two required components to initiate transcription on the gene. What are they, and where do they bind on the DNA strand? 4. How would you know if transcription has been successful? 5. How do negative transcription factors impact transcription? 6.Explain the difference in transcription between Gene 1 and Gene 2. Hypothesize the reason for the difference.
Why did the brown tree snake population on Guam increase unchecked

Who owns the alcoholic beverage of a private club

Answers

The bartender of the Private Club

Answer:

The bartender of the Private Club

Explanation:

someone said that above me and i believe that is right :)

PLS HELP I’m not sure which one it is lol

Answers

Answer:

Option B)

Explanation:

A moon is a celestial body that revolves around a planet.

The others are wrong because, a planet orbits around the sun, not the sun orbiting the planet.

A meteor does not have a fixed orbit, and asteroids orbit around the star near it, in our case, the asteroid belt orbits the sun.

If my answer helped, kindly mark me as the brainliest!!

Thank You!!

A 26-year-old woman is in the clinic today for evaluation of weight gain and fatigue. She is 5 feet 6 inches and weighs 175 pounds. Prior to her pregnancy, she weighed 130 pounds and her maximum weight during pregnancy was 155 pounds. She is now 18 months postpartum and continuing to gain weight despite no change in diet or activity. She reports that the fatigue is getting worse even though her daughter is sleeping reliably through the night and the patient feels she is getting plenty of rest. She takes no other medications and has no significant medical history. Her vital signs today are HR 68, BP 108/60, RR 10, temperature 97° F. The nurse practitioner orders a CBC, TSH, and T4.1. What sources of fatigue is the nurse practitioner evaluating with the CBC, T4, and TSH?2. What other history or clinical findings would be indicative of hypothyroidism?3. The patient’s laboratory values show an elevated TSH and a low T4. What does this mean?4. After starting the patient on thyroid hormone replacement, the nurse practitioner asks the patient to return in 8 weeks to check her TSH level. What is the purpose of this test? What should be done if the test result is abnormal?

Answers

Answer:

Studies based on tsh concentrations would indicate whether the thyroid hormones, which are t4 and t3, are in decline or in deficit.

This deficit may be due to a pathology of the thyroid gland and that is why the tsh study is carried out. The TSH hormone is one that stimulates the thyroid gland through the glandular-nervous axis (CNS), if it is in deficit, you want to say that it is being poorly stimulated.

Other findings of hypothyroidism are overweight, decreased basal metabolism, alterations in the cardiovascular system, and increased blood pressure.

That the TSH hormone is elevated, and there is a deficiency of t4, means that the hormone is suffering from some neoplasm, or some pathology that does not collaborate with the function of the gland, that is, that the axis between the central nervous system and The thyroid gland works perfectly, but what is defective is the gland, the body itself captures this deficit of t4 and stimulates the neuronal pathway even more, releasing more TSH, to overstimulate the thyroid gland and that it can generate the amount of t4 required.

The nurse seeks to know that if by administering t4 and balancing the values of this thyroid hormone, TSH normalizes and returns to its normal value, that is, it decreases and does not overstimulate the thyroid gland.

In the event that TSH does not decrease as expected, there will be a double problem to be solved, one at the nervous level and the other at the glandular level.

On the other hand, if the TSH level normalizes, we could understand that the TSH was increased because it wanted to "solve" the t4 deficit.

Explanation:

The thyroid gland works thanks to the stimulation exerted by the central nervous system through TSH.

The TSH hormone is the one that is responsible for stimulating the exact and fair secretion of t4 and t3, sometimes it tends to increase, due to negative feedback, since the increase in t4 and t3 causes the tsh to decrease and the right balance is reached . In case the hormones secreted by the thyroid are in deficit, this will be captured by the body and will not have this negative feedback, therefore the stimulation of the nervous axis will be increased.

The thyroid gland can suffer from metabolism syndromes where hypoactivity or hypothyroidism is detected, or hyperactivity which is also known as hyperthyroidism, although these syndromes are not the only ones, there are also other pathologies such as malignant and benign neoplasms, hashimoto's disease, among others.

based on the phylogenetic tree, identify approximately how many millions of years ago the earliest South Asian river dolphin evolved. Round your answer to the nearest whole number

Answers

About 0.55 million or 550,000 years ago the earliest South Asian river dolphin evolved.

About 0.5 million years ago the South Asian dolphin evolved due to different environmental conditions. South Asian dolphin have very flexible necks due to no fusion of their neck vertebrae. They are using echolocation to navigate and search for prey.

Research indicates that  South Asian dolphin diverged from a common ancestor around 550,000 years ago that lives in the Indus and Ganges basins so we can conclude that the South Asian dolphin evolved around 0.55 years ago.

Learn more: brainly.com/question/23139449

Answer:

26 million years ago

Explanation:

NEED HELP QUICK!!!1). The Miconia plant is not a native plant to Hawaii. Since its introduction into Hawaii 40 years ago, it has become a popular decorative plant. However, this shallow-rooted plant has replaced many of the native deep-rooted plant species and increased the likelihood of landslides on the island. Which is one of the BEST methods of dealing with this invasive plant?

A) The plant should be shared with the smaller islands.

B) The plant should be fed to the native livestock on the island.

C) The plant should be uprooted from all regions in the island.

D) The plant should be cross-bred with deeper-rooted plants.


2). In the Everglades, a system of canals and levees diverts water to urban areas and the Everglades National Park. This water management system has caused changes in the natural flow of the water during the wet and dry season. Wading birds are especially sensitive to wet and dry seasonal changes. How have water cycle disruptions MOST likely affected wading birds?

A) The reduced salinity results in more eggs being laid.

B) The water quality for feeding has been improved by runoff.

C) The release of water dilutes food sources for their young.

D) The higher water levels allow longer-legged birds to survive and reproduce.


3). In Florida, humans have caused more than 2,000 manatee deaths since 1974. Collisions with boats and boat propellers cause roughly twenty-five percent of all manatee deaths. Another significant cause of the declining population is the disappearance of manatee habitats, resulting primarily from coastal development, water quality problems, and the change in water levels caused by Florida’s flood control systems. A constitutional amendment has been proposed that would protect natural systems and biological diversity. Which would be the MOST likely requirement of a constitutional amendment to protect the manatee population?

A) moving manatees to locations outside of the Everglades

B) restricting manatee hunting in the Everglades to certain times of year

C) raising more manatees in captivity

D) placing a limit on speedboat use in manatee habitats

Answers

The BEST method of dealing with the invasive Miconia plant would be to uproot it from all regions of the island (Option C). Water cycle disruptions have most likely affected wading birds by diluting food sources for their young (Option C). The most likely requirement of a constitutional amendment to protect the manatee population would be to place a limit on speedboat use in manatee habitat (Option D).

What is an invasive species?

The invasive Miconia plant is a threat to the native plant species and ecosystem of Hawaii. The plant grows rapidly and has shallow roots, which can cause soil erosion and increase the likelihood of landslides. Sharing the plant with smaller islands or cross-breeding it with deeper-rooted plants may seem like viable solutions, but it is essential to understand that the plant is already invasive and has caused significant harm to the ecosystem. Removing the plant completely is necessary to allow the natural ecosystem to recover and prevent further damage.

Hence, for first question the correct answer is Option C, for second correct answer is Option C, Option D is correct for third question.

Learn more about the  invasive species here

brainly.com/question/9173006

#SPJ3

1) D because even if you rip all them out, the seeds of the plant are still in the ground
2) D because of the current, short-legged birds might get swept away
3) D because all of the other options would most likely not enforced.

The resistant bacterial cells illustrate what characteristic of life? A) All living things respond to stimuli. B) All living things maintain homeostasis. C) All living things adapt to changes in their environment. D) All living things contain genetic material and reproduce.

Answers

Your answer would be C. All living things adapt to change in their environment.
 
For instance, if people continuously take antibiotics, then the bacterial cells will slowly start to learn and evolve in a way where they resist these antibiotics. This is actually an issue and if the current bacterial cells resist our current antibiotics, then scientists will need to create a new anti-resistant antibiotic. 

I hope your answer was satisfyingly answered. :)
The answer is c, All living things adapt to changes in their environment. The nonresistant bacteria dies off because it hasn't adapted, while the resistant bacteria is still ok. It's kind of like the super-flu, but bacterial, not viral.