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0
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1answer
40 views

Reassociation of DNA

What is the order in which this DNA samples would would reassociate ? e.coli DNA plasmid DNA viral DNA satellite DNA DNA-RNA hybrid This is a homework question and I have not been given any ...
-1
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1answer
91 views

cellular respiration

What are the effects of addition of these chemicals to actively respiring cells ? Which of them would lead to INHIBITION of aerobic respiration ? Would cytochromes be actually taken up by cells ? ...
5
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1answer
59 views

Shade-loving Plants

In shade-loving plants, the light compensation point is reached at low irradiance because: A. Leaves have more chlorophyll per reaction center B. These plants have greatly reduced respiration rates ...
3
votes
1answer
176 views

Hypotonic or Hypertonic solution and why?

A doctor needed to administer 5% albumin to a patient. Albumin is normally administered dissolved in 0.9% saline solution. Since the physician did not have any 5% albumin solution, he diluted 25% ...
0
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1answer
68 views

Lizards are sometimes called cold-blooded because they depend on their surrounding temperatures to keep them warm.

Predict how the composition of the cell membrane of a lizard might change from winter to summer. Justify predictions. Can someone please help me figure this out. Does it have to do with fluidity?
0
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1answer
52 views

Male behaviour during breeding season

The mountain blue bird build nests to attract females and exhibit aggression towards other males during breeding season. Which of the following is likely to give the birds maximal evolutionary ...
0
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0answers
15 views

Osmoregulatory Acclimatization in amphibians

If a frog is gradually exposed to increasing concentration of salts can they acclimatise or will they die of exosmosis ?
1
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1answer
70 views

Which is the correct statement on proteins?

I need help with one of the questions on my biochemistry assignment Choose the correct statement on proteins: a) proteins are folded by alpha-helix b) proteins can preserve their function even if ...
2
votes
2answers
109 views

Hardy Weinberg Equilibrium after 5 Generations

1 There is a population not at HWE where red eye = $a^+$ (dominant) and white eyes = $a^-$. if $a^+/a^+ = 0.6$ $a^-/a^+ = 0.1$ $a^-/a^- = 0.3$ what are the frequencies of the $a^+$ and $a^-$ ...
3
votes
1answer
180 views

Possible Genotypes of 4 Alleles of Adh

There are four alleles of Adh which are Adh-1, Adh-2, Adh-3 and Adh-4. Their respective frequencies are 0.11, 0.84, 0.01 and 0.04. What are the Hardy-Weinberg frequencies of the possible 10 ...
0
votes
2answers
49 views

3 fates of this matter

When an animal eats something, it obtains matter and energy right? But, what are the 3 possible fates of the matter and 3 possible fates energy. I don't understand what they are even asking. What ...
2
votes
1answer
95 views

Genetics problem-Height of a plant

An inbred strain of plants has a mean height of 24cm. A second strain of the same species also has a mean height of 24cm. When these plants are crossed the F1 are also 24cm in height.However, when the ...
3
votes
1answer
85 views

Why are centrioles aligned at 90 degree with each other?

The centrioles are aligned at 90 degree with each other. What is the function of this?
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0answers
31 views

What are the characteristic structures of bacillus M. tuberculosis and what they cause?

I answered to this question: In most forms of the disease, the bacillus M. tuberculosis spreads slowly and widely in the lungs, causing the formation of hard nodules (tubercles) in the ...
0
votes
1answer
45 views

Which fish will have more developed gills?

A fish lives at the depth of 1000-2000m and another at the depth of 200-700m. Which of them would have a more developed gill system ?
0
votes
1answer
29 views

How to Diagnose this hepatitis A, B and C case?

Male patient who is working in the hospital and may be infected with contaminated blood had hepatitis with genome IA 5 years ago. His hepatitis A at that time was confirmed with the rise of anti.HAV ...
1
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2answers
45 views

Is this necrotizing skin infection caused by Staphylococcus aureus?

A 5-year-old boy returns from summer camp with several minor cuts and abrasions on legs. He has fever and extensive cellulitis, subcutaneous tissue and muscles are involved. Necrotic tissues were ...
2
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0answers
26 views

Elevated transaminases after blood transfusion?

This sparks HCV immediately in my mind. However, there may be other possibilities too. What can you deduce from elevated transaminases if you only know that the healthy adult patient received blood ...
2
votes
1answer
38 views

How can a respiratory infection lead to a skin infection?

Example of a case: 5 children develop a bright red rash on the face and turns violet after a few days and then disappears. Then maculopapular rash appears on the trunk, buttocks and extremities. It ...
0
votes
1answer
36 views

Can acid-fast M. tubercolosis obstruct alveoli?

I am not sure which word is the best here for colonisation of alveoli by acid fast-mycobacteria. I found this question, and I am getting confused by the term obstruction of alveoli because I tend to ...
2
votes
1answer
28 views

Which strains of C. diphteria are causing Diphteria toxin?

I got this question: Diphteria toxin is produced only by those strains of C. diphtheria that have which of the following characteristics? Encapsulated glucose fermenters lysogenic for b-prophage ...
3
votes
2answers
187 views

Factor causing Methicilin-resistance in MRSA?

I think the main reason is the natural selection that is causing methicillin-resistance. However, I am not completely sure what this means practically. Here, the original question: MRSA was isolated ...
0
votes
1answer
75 views

Why do bats huddle during late fall?

In the late fall, bats hibernate in clusters with many bats pressed together and holding on to one another. Which of the following supposed advantages of huddling behavior is, in reality, not true? ...
1
vote
1answer
86 views

Is this case Histoplasma capsulatum?

A 62­ year-­old male was admitted to the hospital complaining of shortness of breath. His chest X­-ray showed a rightsided cavitary lesions. His medical history indicated he had smoked one pack of ...
1
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1answer
45 views

Genetics - Is this hybridization possible?

Suppose you hybridize two plants - One has a red flower and a long stalk, the other has a pink flower and a short stalk. This resulted in these 4 type of plants, with ratio 1:1:1:1 Long stalk red ...
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2answers
825 views

What is genomic imprinting?

What is a genomic imprint? How does genomic imprinting take place? If I say that "this" allele is maternally imprinted does it mean that the allele of the gene is passed only by the mother? If a ...
-4
votes
1answer
4k views

What is the difference between the Ureter and Urethra? also between the Renal papilla and Renal pelvis?

Differentiate between the following: Ureter and Urethra Renal papilla and Renal pelvis It is not given in my book. Please help.
3
votes
2answers
630 views

Why do we squint when tasting very sour things?

Sometimes while tasting a very sour thing (like tamarind, lemon etc.) our eyes squint immediately and involuntarily for a second, but a little later becomes normal again. Why, and how, does this ...
1
vote
1answer
105 views

Single Nucleotide Polymorphisms and diseases

I am writing a report on how Single Nucleotide Polymorphisms occurring in each of these regions: Transcription factor (TF) binding sites Epigentic signals Splicing variants MicroRNA binding sites ...
1
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1answer
61 views

Breaking of fats

There is a question I encountered. Why is fat harder to digest ? A) It has ester bonds. B) It is not easily soluble in water. Which is the most appropriate answer?
-2
votes
1answer
354 views

Amino acid characteristics that determine their chemical properties?

What chemical aspect of amino acids results in their having different properties such that the chemical and physical properties of polypeptides vary with both amino acid content and amino acid order? ...
1
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3answers
240 views

Diffusion across cell membranes

I got this question and don't really understand the difference between the answers. Diffusion is (in cell membrane): a) passive by nature, no metabolic energy is needed b) driven process by ...
0
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2answers
155 views

Recent and good quality articles on systems biology [closed]

I'm a biotechnology student and I have to write a sort of non-experimental thesis (30 pages long) within the end of a three years study. I'm very interested in the "systems biology" field and I'm ...
1
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2answers
111 views

Hardy-Weinberg Equilibrium: To compute probability of finding two siblings (random mating)

I've been working a little with M. G. Bulmer's Principles of Statistics (Dover, 1979) and cannot see how to properly compute half of one question. This should be a basic probability computation, but I ...
1
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1answer
148 views

Two brown-haired people have two children, P and Q. P has blond hair. Q has brown hair. What is the probability that Q is heterozygous?

Two brown-haired people have two children, P and Q. P has blond hair. We therefore believe that each parent is heterozygous and that blond hair is a recessive trait. Q has brown hair. What is the ...
0
votes
1answer
107 views

How to classify equilibrium points [closed]

I have the two differential equations: $$\frac{dN_1}{dt} = N_1(2 - N_1 - 2N_2)$$ $$\frac{dN_2}{dt} = N_2(3 - N_2 - 3N_1).$$ I worked out the equilibrium points to be at $N_1 = 0, \frac{4}{5}$ and ...
0
votes
2answers
162 views

Deterministic model of lambda-phage lysis/lysogeny [MATLAB]

Project 1 Base: Can someone please help me understand what I need from Project 1 Base code to do questions 1 and 2 from the first image? I'm new to MATLAB so a thorough explanation would be ...
1
vote
1answer
260 views

Number of reading frames in nucleotide sequence

In class of molecular biology was posed this question: "How many reading frames start in sequence of nucleotides 5' ... ATATGAATGATGACAT... 3' ?"
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0answers
48 views

Polymerase Observations

DNA polymerase I (PolI) contains polymerase, 3'-5' exonuclease, and 5'-3' exonuclease activities in a single polypeptide chain of molecular weight 109 kDa. If E. coli Pol I is exposed to the protease ...
6
votes
1answer
288 views

How does Topoisomerase II inhibition affect cancer cells?

Topoisomerase II poisons represent some of the most important and widely prescribed anticancer drugs currently in clinical use. These drugs encompass a diverse group of natural and synthetic ...
2
votes
1answer
73 views

Does this patient have HHV6 or HCMV after transplant surgery?

I have been given mock results from a PCR test on blood samples taken from kidney recipient patients and their donors. The PCR reaction can detect single copies of viral DNA. I have been asked to ...
4
votes
1answer
59 views

Parsimony (cladistics)

I don't understand how to sum the changes in a phylogenetic tree. Here for example: http://www.med.nyu.edu/rcr/rcr/course/phylo-cladistic.html How do you end up with 8 for the first and 9 for the ...
1
vote
2answers
94 views

Will climate change affect flower population?

There is a flower population elevated 1000 meters above sea level. If climate change causes a 12 degree C increase in temperature over the next 10 years, what will happen to the flowers?
2
votes
1answer
71 views

What causes tree lines?

There is an area of where there is a distinct line of only trees on one side and only shrubs on the other (right next to each other). What could cause this? My attempt: I said there could be a ...
4
votes
2answers
2k views

What are the advantages and disadvantages of using beta-galactosidase compared to luciferase as a reporter gene?

In the University labs, we have used Beta-galactosidase as a reporter gene to quantify the expression initiated by the stress-response promoter in yeast. This was done by exposing one of the two ...
2
votes
1answer
31 views

What range of dose should be used?

This is a dose-response experiment testing a new cancer drug. the darker line represents cancer cells. what range of dose should be used? I think it's 2-4 because this affects cancer cells only. is ...
1
vote
0answers
28 views

How could a pure culture be represented by more than one ssu rRNA sequence?

Your lab works on an organism isolated from radioactive waste. However, you show that 3 very similar, but not quite identical, ssu-rRNA sequences can be amplified from the culture even though it is ...
2
votes
2answers
877 views

What is the purpose of measuring both VS (volatile solid) and TS (total solid)?

In the biogas process you often measure Volatile solid and Total solids. Can any one explain these concepts more accurately and why it is interesting to look at these properties. The biogas process ...
2
votes
1answer
79 views

At what substrate concentration will an enzyme work at 40% of its maximum rate if its Km = 0.095M?

The question involves the Michaelis-Menten kinetics equation. Here is what I did: I took the Michaelis-Menten equation, replaced v with 0.4Vmax, canceled the Vmaxes (one on each side), and solved ...
2
votes
1answer
43 views

Similarities Between Cells?

Which of the following are usually identical between a lung cell and a brain cell, from the same person, assuming that they are normal (non-cancerous) cells? Circle your choice(s). ...