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4
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1answer
320 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
votes
1answer
106 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
votes
1answer
56 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 ...
2
votes
1answer
34 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
vote
1answer
128 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
179 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
307 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
50 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
169 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
144 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?
1
vote
0answers
44 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
57 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
38 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
vote
2answers
56 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
votes
0answers
35 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
46 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
39 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
37 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
305 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
124 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
118 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
vote
1answer
50 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 ...
2
votes
2answers
3k 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 ...
-3
votes
1answer
14k views

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

Differentiate between the following: Ureter and Urethra Renal papilla and Renal pelvis It is not given in my book. Please help.
6
votes
3answers
2k 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
126 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
vote
1answer
65 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?
1
vote
1answer
517 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
vote
3answers
387 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
votes
2answers
182 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
vote
2answers
178 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 ...
2
votes
1answer
191 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
122 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
237 views

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

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
684 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' ?"
6
votes
1answer
488 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
79 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
71 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 ...
2
votes
2answers
105 views

Will climate change affect flower population?

There is a flower population elevated 1000 meters above sea level. If climate change causes a 12⁰C increase in temperature over the next 10 years, what will happen to the flowers?
2
votes
1answer
73 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 ...
7
votes
3answers
4k 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
32 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 ...
2
votes
2answers
2k 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
105 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
47 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). ...
2
votes
2answers
356 views

Translate DNA to Protein

Assuming the sequence shown is read left to right, what is the sequence of the protein produced? sequence: 5’-ATGTACTTCCATCTGGAATAG-3’ MY ATTEMPT: I know RNA is synthesized 5 to 3. This is ...
2
votes
1answer
102 views

Which cells will pass cancer to offspring?

Each of these types below contains a DNA mutation. Which type(s) will affect the children of the individual whose cell it is. Red blood cell T cell Skin (epithelial) cell Neuron from the brain Sperm ...
1
vote
1answer
7k views

Which enzyme catalyzes transcription and which translation?

My attempt: Transcription - RNA polymerase Translation - aminoacyl tRNA synthetase I know that the ribosome almost runs translation, but I don't think ribosomes are enzymes, which is why I went ...
2
votes
2answers
5k views

How do trees use Adhesion and Cohesion to move water against gravity?

I have an AP Bio class where I have to name 3 properties of water and I chose adhesion and cohesion for one of them. I'm having trouble finding out how exactly trees use adhesion and cohesion to move ...
2
votes
1answer
78 views

Are there any organisms with larva more advanced than adult form?

Usually adult organisms are more sophisticated than corresponding larva, i. e. frogs, mosquitoes, fish. Are there species where the opposite is true?