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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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cancer pedigree homework: risk of inheriting BRCA2 mutation

The proband was diagnosed with ovarian cancer and was tested postive for BRCA2 mutation. I want to know what is the risk of her sister inheriting this mutation? How do you work that out? Since BRCA2 ...
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3answers
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Evolution question on speciation? Really confusing!

Okay, my teacher assigned this homework question, but nothing like this was ever given in our textbook. Suppose that a type of tree tends to speciate over 10 million years and a species of fly tends ...
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1answer
55 views

How do I determine this logistic growth model formula?

The Question Two yeast cells were placed into a special container to which food was continually added, to keep it at a constant concentration. All other factors were set for optimal yeast ...
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1answer
42 views

In plant photosynthesis, in the light dependent reactions, why is 3 ATP produced per 2 H2O?

I've been looking at the light-dependent reactions on Wikipedia and Khan Academy. This is the net reaction: $$2H_2O + 2NADP^+ + 3ADP + 3P_i \to O_2 + 2NADPH + 3ATP$$ So for every $2H_2O$ I expect $...
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1answer
32 views

What is the difference between optokinetic and vestibular nystagmus?

Optokinetic nystagmus is for stabilising the pictures we see when we are observing moving objects for example if we are rotating on an office chair. If we wear a mask while rotating however, the ...
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1answer
26 views

Blood pressure in various blood vessels and heart

What are the typical systolic and diastolic blood pressure in arteries,capillaries, veins and the heart? I know it must be highest in the arteries. arteries>capillaries>veins Arteries: 120-80mmHg (...
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2answers
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About. Autosomal recessive diseases in genetics

What happens if homozygous dominant alleles are present in an individual for an autosomal recessive disease will he be affected ?
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2answers
91 views

What happens between two nodes in an evolutionary tree?

Hey guys can you help me with this one!? What happens between two nodes (in an evolutionary tree) or a between a node and a tip? A) at least one character changes B) all organisms die C) ...
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1answer
34 views

Calculating PCR Cycles

I have a problem understanding a PCR exercise, it says to calculate the number of cycles to get 1µg of the DNA fragment, starting from 10ng and then from 500ng, I know about 2^n, and the exercise even ...
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1answer
66 views

Protein electrophoresis

Three proteins A, B and C of equal molecular weight are being investigated in a study. They contain six, four and four cysteine residues respectively. Only Proteins A and B were treated with β-...
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3answers
149 views

Why does photosynthesis occur even in blue light when the photocentres are activated in red light

From Engelmann's experiment Engelmann used this device to illuminate a strand of Cladophora (not Spirogyra) with light from the visible spectrum, exposing different sections to different ...
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0answers
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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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1answer
53 views

When in the cell cycle is the number of chromosomes normally reduced?

Page 96 of the Study Guide for Campbell Biology, 11th Edition has the following question: A reduction in the number of chromosomes per cell occurs a. During meiosis I b. During meiosis ...
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1answer
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How are chromosomes counted at the end of mitosis in a plant cell?

Page 89 of the Study Guide for Campbell Biology, 11th Edition has the following question: A plant cell has 12 chromosomes at the end of mitosis. How many chromosomes would it have in the G2 ...
3
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1answer
136 views

Is pith a ground tissue with no specialized function?

Here is a question from the book My Max Score SAT Biology E/M Subject Test (where the SAT is the exam taken by American high school students): Ground tissue with no specialized function A. Xylem ...
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1answer
35 views

How many birds in this population would be expected to have either red or white feathers?

Question: The red and white feather pattern of a bird is determined by a gene that has two alleles, band R and W,which show codominance. Some birds have completely red feathers (RR),some parrots ...
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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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0answers
28 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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1answer
117 views

Why does this genetic pedigree show an autosomal dominant allele at one generation but not another?

Questions 186-188 of the GRE Biology Practice Test are prefaced with this genetic pedigree: Questions 186-188 refer to the following pedigree for the inheritance of a very rare human disease over ...
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0answers
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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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1answer
84 views

How to find which mutation in a protein is related to a disease?

I have the FGFR3 protein in UniProt and they ask me to find which of the following four mutations is related to a disease: N98F, P64K, T79S, or F384L. Where can I find such information? Thanks
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1answer
111 views

Why doesn't oligodendrocyte produce neurilemma

I was searching literature related to neurilemma and oligodendrocyte and came across these lines from WP (Neurilemma) Oligodendrocytes do not have neurilemma because excess cytoplasm is directed ...
2
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1answer
98 views

Why do proteins targeted for chloroplasts require two signal peptides?

Question #11 of the GRE Biology Practice Test says that proteins targeted for chloroplasts require two signal peptides: Targeting of a newly synthesized protein is most likely to require two ...
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1answer
170 views

How to find the amino acid that is bound to a tRNA with the anticodon? [closed]

What amino acid is bound to a tRNA with the following anticodon: $5^{\prime}$ A U G $3^{\prime}$ The answer is Histidine. What amino acid is attached to the tRNA with the ...
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3answers
80 views

Biological validation of computationally determined gene-gene interaction

How can a computationally determined three-way gene interaction be biologically validated? What kind of assays or tests must be performed using cell/tissue-based and/or mouse models to prove that the ...
3
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3answers
78 views

Is it possible to prove that a hand sanitizer can kill 100% of a person's germs?

We have a project for Economics, and we need to advertise something that consumers will be willing to buy. My group thought of "improved" hand sanitizer. So, instead of it killing 99.9% germs, we ...
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0answers
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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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0answers
27 views

How to design shRNA?

So I have to design a shRNA and insert it in a vector with on the 5'end a Xhol restriction site and at the 3' end a BglII site. The gene of interest: ...
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1answer
52 views

If an antiserum was raised in a buffalo by injecting it with monkey red blood cells, what would be the full name for this antiserum?

Im confused, i've attempted this & what i got is buffalo anti-monkey red blood cell antiserum. I'm not sure if this answer is right
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58 views

Phytoplankton for Indoor Air Quality

Will keeping a phytoplankton culture at home improve air quality? Are there any studies investigating this?
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1answer
96 views

Is this answer about the limiting factor correct?

The graph shows the result of adding both phosphorus and nitrogen to different algae populations. I have a hard time figuring out why the correct answer is C, I thought that groups 4 and 5 would have ...
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1answer
45 views

Advanced Higher Biology 2017 - EPT Index

I was recently completing a biology past paper the Scottish SQA 2017 Advanced Higher Biology Qualifications. The question is as follows: To solve this, I did: EPT Index = 100*(striped stonefly + net ...
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0answers
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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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1answer
32 views

Sex determination in Drosphila [closed]

Ive been taught that its based on genic balancing. But I recently saw this question that has caused me some doubt. I thought it would be the 1st option but unfortunately they said it to be the 3rd. ...
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1answer
50 views

What is the type of conservation in which seed banks are an example? [closed]

Firstly I think this question is quite ambiguous (I did not come up with it) so sorry. I have only come across 4 'types' of conservation: environmental, animal, marine, and human conservation. I am ...
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0answers
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What is the main difference in primary production for non-phytplanktonic production?

I'm trying to see if someone can help me with giving a short answer on the question above. The question I cannot seem to answer myself is related to coastal and zone management. The question relates ...
2
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1answer
146 views

How would one go about isolating a specific mRNA out of a pool of others? [closed]

I'm writing an essay about DNA recombinant techniques where the question asks to outline all the steps to arrive at having a colony of bacteria expressing a gene of interest.The question makes you ...
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2answers
36 views

Number of different clones of B lymphocytes

My professor told us that there are about a million different B cells based on their surface receptor. I have read that we have about 30000 genes in all. Since receptors are proteins how do these ...
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1answer
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Prove that the worms are unicellular

In Biology class our teacher divided the class in two groups. Our group(i'm in) has to prove that the worms are unicellular(although it is not true). The other group has to prove that we are wrong. ...
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0answers
42 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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1answer
43 views

Understanding Genetic Dynamics of Specific Problem

The following questions comes from International Biology Olympiad 2014, theoretical part B. It states: Earlier research suggested that the red flower pigment of plant species was the result of a ...
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1answer
82 views

law of independent assortment [closed]

Self fetilization of F1 dihybrids, following independent assortment of alleles result in: ...
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0answers
31 views

Prepotential in cardiac cells

I came across this MCQ in my physiology book, it says: Prepotential ........... a. is present in ordinary ventricular muscle fiber b. slope is decreased by sympathetic stimulation c....
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0answers
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What causes this shade in gel electrophoresis

Currently in uni I have recently done a exercise of extracting DNA from yeast cell. This is somewhat related to homework, but instead of asking about the answer im wanting to understand why there is a ...
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1answer
367 views

Which statement is incorrect for Rubisco?

My question is this: Which of the following is NOT correct for rubisco? a. It is the most abundant enzyme b. It catalyzes two different reactions c. It is involved in photorespiration d. It is not ...
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2answers
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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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2answers
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Why aren't 'exons' named 'introns'?

Why are introns called 'introns' when they are the actual ones who are getting spliced out from the pre-mRNA. Shouldn't exons be named introns as they are the ones that are 'in' and are not 'exiting'? ...
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1answer
68 views

How do you find probabilites of carrying an X linked recessive disease in a blank pedigree given only one phenotype?

In the above pedigree, the black square indicates the male affected with Hemophilia which is a X-linked recessive trait. What is the probability that the proposed child, which is a male (indicated as ?...
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2answers
123 views

Is the xylem like a tissue paper?

I am a 5th grader learning about the plant transport mechanics and I learnt that the xylem is made up of dead cells.So if water travels up the xylem and water travels only 1 way, is it like how water ...
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2answers
357 views

Intermediate of Krebs cycle that can form Chlorophyll?

This was a question in a test in my school today. Q) Which intermediate of Krebs cycle further can form chlorophyll? A) Oxaloacetic acid B) Citric acid C) Succinyl CoA D) Fumarate Given answer was ...