Questions tagged [homework]

This tag indicates that the question is likely based on a home assignment in biology-related university or high school courses or is about an elementary concept that may seem trivial to biology professionals. Please see the homework policy on meta before asking homework questions.

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What change would you expect in phospholipid orientation of the membrane if the enviornment were mostly heptane?

The external and internal environment of the cell is basically water, thus phospholipids organize themselves the way they do (bilayer). If the environment were to magically become mostly heptane, how ...
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133 views

For which taxonomic levels are xylotomical, embryological, and palynological evidence each most useful in determining species relationships?

From the 2010 USABO Semi: In plant systematics, three lines of evidence may be useful in determining relationships; xylotomical (wood anatomy), embryological and palynological. Match these ...
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51 views

How do spiders get silk from their spinnerettes?

I'm 13 and writing a report on spiders. How do they use the silk protein gel from the spinnerets? How does it get from the spinnerets to the web? P.S. I know how silk is created, all the way up until ...
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465 views

Cause-and-effect questions about growth and development of plant

I need to solve some cause-and-effect problems. The problems are related to growth and development of plant. "Growth and Development" chapter is the first chapter in third level of high school (senior ...
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93 views

Problem involving selfing (inbreeding it with itself) a plant to generate purebred lines

I am working on a past exam problem where the first bit is as follows A plant is repeatably selfed to generate inbred lines. Let $\mathbb{P}(He|He)$ denote the probability that a heterozygous ...
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1answer
46 views

How is ligand binding modeled?

I have the following exercise to solve: To be honest, for both parts, my only idea so far would be to divide the rate expression by the sphere area and multiply by the new available areas (that of a ...
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35 views

Net electrical load of a peptide

I have to determine the electrical charge of the next peptide chain: C - E - H - P I know that this page is not there to raise doubts about this style, but I have looked for resources on the ...
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84 views

eosinophil question

Which of the following statement(s) is/are incorrect? A. All cells of the immune system originate in the Bone Marrow B. Lymphoid progenitor cells originate from a pluripotent stem cell C. B cells ...
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49 views

Sucrose inhibit onion root mitosis? Why?

I am doing an experiment about onion root growing. I had put an onion in different solutions of $C_{11} H_{22} O_1$ in H2O —with the root touching the water—: 0,1M; 0,2M; 0,3M; 0,4M; 0,5M. The ...
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267 views

Light microscope specimen size

I was going through sample questions for Science Olympiad, and one of the questions went like this: A cell is observed through a light microscope at 4x magnification. The cell takes up about half ...
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How to tell if something is an organ or apparatus?

An apparatus is defined as Physiology. a group of structurally different organs working together in the performance of a particular function. An organ is defined as: Biology. a grouping of ...
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108 views

Plaque rupture flow chart reading

I am having a bit of trouble interpreting flow charts given in my biology question sets. Given the following stimulus The Question is : In which of the following options does each substance play ...
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1k views

What is the probability of an XX female or XY male?

Homework question In genetics the chance of having a male or female is 50% for male and 50% for female. Using factorial method and Punnett Square prove or disprove the claim. My answer Using the ...
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133 views

Minichromosome maintenance protein structure and function

I am having difficulty answering three homework questions which relate directly to Chong et al. (2000). Questions The authors have determined that MtMCM is able to bind both ssDNA and dsDNA (see ...
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951 views

Which DNA fragments do not have expected sizes on this gel electrophoresis?

The problem is such: After performing a PCR, the vector carrying the PCR fragment with two restriction enzymes (Nhe1 and Asc1). The DNA samples were then separated using agrose gel electrophoresis ...
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72 views

height and bryophytes

Why does being taller provide advantages for Bryophyta but being shorter is better for Marchantiophyta? What disadvantages could being taller have? I think that by being taller, you have better ...
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68 views

How to gauge the clinical significance of specific cell type presence?

How does one decide whether the presence of certain cell types is clinically important or negligible? Would the presence of certain cells in conjunction with other symptoms be enough, or should it be ...
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784 views

How many proteins are synthesized in human body throughout life?

My idea to calculate this is: Define up to what age will do the calculation. (for instance 60) Determine how many cells born and died up to that point in life. (by type of cell) Determine how many ...
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58 views

recombinant gametes

Suppose you are able to observe under a microscope the total number of meiotic divisions occurring in one gonad of a given individual and to outnumber exactly the crossovers between two given loci ...
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50 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 ...
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32 views

Cooperative Enzyme Question

I'm currently studying for the MCATs. After doing some biochemistry practice questions, I came upon a question that I believe may be incorrectly posed. I was wondering if I'm correct in saying this or ...
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76 views

True or False: Endocytosis delivers vesicles directly to the cis face of the Golgi complex

Does anyone know the answer to this question, and also the explanation of to why this is True or False? I know that Endocytosis is the process of uptake of materials into cells including ...
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44 views

Monohybrid Recombinant Frequency? (three point Gene Linkage)

I am curious to know if it is completely impossible calculate recombinant frequency for monohybrids ( three point link, gene map etc.) Here is an example: Marker 1 xx= 25 xy=100 yy= 20 Marker 2 ...
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21 views

Is this tree poisonous?

I touched this tree on my visit to South Africa and a huge rash developed on my body,please help,what is the name of this
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2answers
3k views

Genes & Map Units

Two genes of a flower, one controlling blue (B) versus white (b) petals and the other controlling round (R) versus oval (r) stamens, are linked and are 10 map units apart. You cross a homozygous blue ...
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41 views

Homework: Diffrentiate between 2 toads

How to differentiate between 2 toads one of them result of artificial parthenogenesis and the other from renucleation? I answered that the toad resulting from artificial parthenogensis is identical ...
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25 views

response elements in transcription regulation

I'm studying eukaryotic gene regulation and I want to know whether there are some instances where transcription factors don't need to bind to response elements to initiate transcription. RNA ...
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1k views

Solute potential of sucrose relative to NaCl

Does 1M NaCl or 1M sucrose solution have a more negative solute potential? I was thinking that for the same volume of solution, (eg 1 dm^3) there will be 2 mol of ions in NaCl solution and 1 mol of ...
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724 views

When is it unacceptable to measure dry mass in an experiment to measure growth of plants?

I'm an A level student (British high school final year) and I was doing an exam question which asked for the design of an experiment to test the effect of light intensity on the growth of a certain ...
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34 views

How to read from flow chart

So I got the following picture and question: a) Assume that F1 = 10 mmol h$^{-1}$ and the flow is not negative (ie f$_i$ ≥ 0, i = 1, ..., 8). What is the most you can produce of the polymer DCDE (i.e....
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34 views

How could you measure the rate of light reactivity/ photosynthesis of a cell in a lab setting?

For a lab I must take Volvox protist cells and expose them to specific wavelengths of light. How would I know they're even reacting? The assignment I've been given does not explain what I should even ...
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67 views

Thyroid transplanted to the abdomen

This question was posed in our endocrinology class, however I have no idea how to answer it: The thyroid gland of a 5-year old boy is transplanted from its normal position in the neck to the ...
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99 views

Interpretation of table on analysis of genetic diversity between groups

I am very confused about how to interpret Table 8.3 in Smith's Evolutionary Genetics. Is the GST in the table the same as the G,ST (with the comma), which is defined (pg. 156; Box 8.3) as "the ...
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20 views

Production of $CO_2$ basal metabolism test

Can the production of $CO_2$ be used as a type of basal metabolism test? Explain. The answer to this is obviously yes, but I don't know how to explain it. Would the following be a good explanation? ...
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739 views

How's maturation different from differentiation/activation of B lymphocyte?

I was reading Wikipedia that said $-$ In mammals, B cells mature in the bone marrow, which is at the core of most bones. In birds, B cells mature in the Bursa of Fabricius, a lymphoid organ. So ...
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497 views

Can the respiratory quotient be calculated from a formula or must it be measured directly?

I found the following question on the Respiratory quotient: A normal human diet has a Respiratory quotient (RQ) of approximately 0.85. Given that pure oxidation of fatty acids has a Respiratory ...
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26 views

Any books/publications about what life was like before antibiotics?

Just wondering. We've been discussing antibiotic resistant bacteria a bit in lecture, and how we're slowly sinking into a pre-antibiotic era again.
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3k views

Construct a restriction map of a linear fragment of DNA using the following data?

I've attempted to do the single digests, and the double digests, but cannot complete the map.... I've attached what I've done so far DNA Sizes of Fragments (bp) uncut DNA 900 DNA cut with EcoRI ...
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361 views

Relation between heterozygosity and allelic diversity in founder effects/bottleneck?

Can someone try to explain me why allelic diversity falls faster than heterozygosity, reminding you that we're talking about bottleneck or a founder effect? Look at this graphic: It's clear to me ...
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18 views

Which fractions are enriched for siRNA cleavage activity by comparing electrophoresis?

Size exclusion column chromatography was used to separate the proteins in a Drosophila cell lysate to attempt to identify the protein complex responsible for processing long dsRNA into siRNAs. SDS-...
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final control prior to transfecting an expression vector into a mammalian cell?

I have been asked a general question: Once I have cloned a full-length cDNA into an expression vector, what final important control must I do before I transfect this into an embryonic stem cell line? ...
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833 views

mutations induced by transposons

Question: In contrast to chemically-induced mutations, mutations induced by transposons are more likely to ... be lethal de dominant be stable revert to wild types be a gain of function The answer ...
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252 views

Reasons for strange heart rate graph following exercise (line going up and down)?

Following a 2 minute general jumping and movement exercise designed to involve the entire body, the pulse was taken every minute for ten seconds. Strangely, the graph appears to jump up and down, for ...
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446 views

Calculating the recombination factor of four point genetic cross?

So, I'm trying to work out the recombination factor (RF) from this set of data: Which shows the 16 phenotypes of progeny of a cross of Saccharomyces cerevisiae yeast. I know how to go about a three ...
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1k views

Evolution of a Population

Scientists observe a newly established population of sexually reproducing plants growing on the shore of a small island. An observable trait of the plant has two possible phenotypes. It is determined ...
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1k views

How can we determine the polarity of fat molecules?

I'm trying to solve a question in a biochemistry quiz, which is asking for classifying a set of lipidic derivatives, by increasing polarity. Unfortunately, we didn't cover the classification of ...
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71 views

Genetic tests on S. cerevisiae to determine mutation locus on genes

I am studying the metabolism of galactose in the budding yeast Saccharomyces cerevisiae. After a random mutagenesis screen, several mutant strains were isolated that grow well in glucose but are ...
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63 views

Why do Sorghum Bicolor leaves roll up?

In A level Bio today we talked about abcesic acid as a stress hormone, and its ability to reduce osmotic potential around guard cells to close stomata. My question is, is abscesic acid in sorghum ...
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93 views

Paired-end mapping exercise

Pair-end mapping (PEM) is a technique that allows to detect structural variants in DNA by obtaining paired-end reads and the comparison of their positions in a reference genome. Then among libraries ...
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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 ...