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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8 votes
1 answer
417 views

Why were there relatively fewer papers about cell fusion before the 1950s?

While working on my cell fusion technology report, I saw PubMed's cell fusion graph of results by year. There have been studies or research since the early 1900s, but until the 1950s, there were no ...
1 vote
2 answers
48 views

Hardy-Weinberg Equilibrium help

I am currently working on understanding Hardy-Weinberg Equilibrium problems. I have come upon two examples of a problem in two different Youtube videos which got me confused: Example 1: 19% of a ...
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1 vote
1 answer
50 views

Albino pedigree question

https://www.proprofs.com/quiz-school/playquiz/?title=pedigrees-quiz is a link to the website containing this question.
2 votes
0 answers
55 views

What causes Erythroblastosis fetalis?

So this is what I understood about the disease by researching about it When a Rh-ve mother has a Rh+ve baby in her womb, The placenta prevents mixing of fetal and maternal blood preventing antigen ...
0 votes
1 answer
49 views

What is the difference between a macrophage and dendritic cell?

I am aware that both these cells (monocytes) are phagocytes and are able to present antigens upon their own Class II - MHC integral proteins. Other than their difference in structure (size and shape), ...
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3 votes
1 answer
107 views

A level 2022 Biology percentage increase question

In January 2022 WBI12/01 they asked: 9c. In 1963, there were only three males and 12 females of C. hoodensis left in the wild. These 15 tortoises were used in a breeding programme. ii.The wild ...
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0 votes
0 answers
51 views

Price Equation in Evolution

I am trying to solve for $\text{cov}(w_i,z_i)+E(w_i\Delta z_i)$ as it apears in Price Equations in terms of the mean $\overline{w}$ and variance $\sigma_{w}^2$ of the fitness of a population where I ...
2 votes
1 answer
31 views

Gametes produced after single and double cross overs

A female genotype, shown as abc / +++ produces 100 meiotic tetrads. Among these, 68 showed no cross over (NCO) events; 20 showed single crossover (SCO1) between a and b; 10 showed single crossover ...
3 votes
2 answers
88 views

Question about using Mendelian inheritance to reverse-guess the parent genotype

I would like some help with a question about Mendelian inheritance, based on the following information (I assume this is autosomal and not sex linked): -- Start of information -- "As flatfish (...
1 vote
1 answer
157 views

Time required for DNA replication in E. coli

In a particular strain of E. coli, it was observed that DNA polymerase could add nucleotides to a growing chain of DNA at the rate of 600 per second. If the genome of this organism is 1.1mm long ...
1 vote
0 answers
107 views

Calculation of solute, pressure and water potential

What would be the water potential (Ψw), solute potential (Ψs) and pressure potential (Ψp) at equilibrium when a cell with Ψs= – 0.7 MPa and Ψp= 0.7 MPa is placed in a solution with Ψs= – 0.5 MPa? (...
0 votes
0 answers
76 views

Surface Area to Volume Ratio and Ice Baths

Hi I was taking a practice test and stumbled across this question. I couldn't find information about this on the internet. Does anyone know why B is the answer? Thanks
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1 vote
0 answers
62 views

How can I confirm that this pedigree is of a pseudodominant trait?

This is an example of an autosomal recessive trait masquerading as autosomal dominant. I carried out genetic analysis for each generation as if the trait was either recessive or dominant, and both ...
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2 votes
1 answer
55 views

Question about manifestation of an X linked disease (homework help)

I am doing some practice exams and came across this question. Perhaps the answer is a lot simpler than my reasoning, but after discussing it with others, I still disagree why the answer is clearly and ...
3 votes
1 answer
83 views

Problem involving genetic interactions in yeast

I'm having difficulty with the following problem: In yeasts, genes MEC1 and SGS1 favor survival in response to HU (hydroxyurea). In the figure below, Δ indicates homozygosis for the mutant allele ...
0 votes
0 answers
96 views

What are the small white dots in an onion cell seen under an electron microscope?

We had to use an electron microscope in class for an assignment and used onion cells. On the 40x and 100x magnification there are tiny white dots and I was wondering if someone could tell me what they ...
-1 votes
1 answer
248 views

What is a downstream target?

For example, in a systems biology analysis, what is a "downstream target" and why are these significant in pathway analyses? I have looked for answers on Google, DuckDuckGo, Wikipedia, etc. ...
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1 vote
1 answer
47 views

Are restriction sites added on to the ends of a DNA fragment or are they just conveniently there?

For a DNA fragment to be inserted, it must have two restriction sites on either end. My textbook makes it seem that this is naturally occurring but it seems a little too convenient, are they added in ...
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1 vote
1 answer
83 views

Explain why bones cannot undergo interstitial growth as cartilage does

I got a question from a textbook <<Seeley's Anatomy & Physiology Twelfth Edition>> that does not have an answer at the back of the book (only odd numbered questions do have an answer ...
2 votes
0 answers
71 views

How does Propionibacterium acnes survive the antibacterial effects of sebum?

Sebum has antibacterial properties due to sapienic acid and oleic acid according to this article on sebum. According to the same article, desaturation of fatty acids increases acne development. ...
0 votes
1 answer
46 views

Does hormone participate in metabolic activites?

strong text My take on question- All hormone are not water soluble, some are fat soluble also so this option is definiely wrong. Thyroxine Hormone is do stored in the body in Follicle of thyroid ...
1 vote
1 answer
78 views

How many cells are there in C. elegans in each hour of its life?

I'm a high school student planning to write a math essay to model changes in the number of cells in a living organism over time. C. elegans is the only organism that I know with a known number and ...
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6 votes
1 answer
273 views

How does increased resistance to flow decrease blood pressure?

I have recently encountered this question: Waldenström's macroglobulinemia is a condition which causes increased blood viscosity due to high protein content in the blood. How would Waldenström's ...
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3 votes
1 answer
94 views

How much oxygen is released by Hemoglobin per 100ml blood

Question Red blood cells carry oxygen from lungs to the whole body. The percent saturation of hemoglobin with oxygen depends on the partial pressure of oxygen. Higher partial pressure of oxygen means ...
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2 votes
1 answer
157 views

Number of homozygous recessive offspring

A question from the KVPY-SX examination, organised by the Indian Institute of Science (IISc) in Bengaluru, India, held on 3rd November, 2019. A plant heterozygous for height and flower colour (TtRr) ...
1 vote
1 answer
160 views

Understanding Contig NG50

My goal is to do a de novo assembly of a jellyfish. At the moment I'm busy checking papers that did de novo assemblies but I also got some jellyfish papers Then I stumbled accross this: Contig NG50 ...
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0 votes
2 answers
156 views

How can we know which alleles are together on a chromosome?

This illustration says that if the two homozygotes pr+ pr+ vg+ vg+ and pr pr vg vg are crossed to produce a heterozygous offspring (pr+ pr vg+ vg), then: this cross gives us exactly what we need to ...
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0 votes
1 answer
141 views

What is the map unit between the genes?

While doing some biology I came across this question: The following tables present results of plant crosses involving two linked genes: S is a seed-color gene, and L is a plant-height gene. Each gene ...
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4 votes
1 answer
126 views

renal portal system

I am a high school student. In my textbook it is written that Mammals don't have renal portal system because they have four chambered heart. I understand that the four chambered heart keeps the ...
-2 votes
1 answer
75 views

Check simple human fetus answers

Based on this image and questions, could someone please check my answers? Question 1: At which one of the following points will the blood passing the point be more oxygenated after birth than before ...
-2 votes
1 answer
68 views

What is the thickness of the membrane if only alpha helixes are embedded of a transmembrane protien?

Given is the representation of a transmembrane protein. Calculate the thickness of the membrane if only alpha helixes are embedded in it. One turn = 5.4Å Please read: The reason I didn't submit my ...
0 votes
0 answers
31 views

Why do huskies have markings above their eyes

[1. Dogs in Antarctica pulling sleds
0 votes
1 answer
185 views

Confusion about how to compute probabilities for linked genes

I am confused about how to compute probabilities for linked genes. The problem that I am solving is this: P generation: AAbbddEEff X aaBBDDeeFF. If A and B are 40 centimorgan apart, what is the ...
1 vote
1 answer
166 views

How deep underwater could you breathe using a tube which breaks the surface until the water pressure makes it impossible to inhale air?

I'm struggling with a question asking how deep you can breathe underwater using a hollow reed before the water pressure makes it impossible to inhale. The question asked to use this data of maximal ...
1 vote
2 answers
138 views

Why do genes, encoding the same proteins and in the same conditions, have different expression?

Is it possible that two genes, which come from two different cell cultures and which encodes the same protein, produces different quantity of mRNA? If yes, why? My question comes from the fact that I ...
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-1 votes
1 answer
58 views

Am I reading this respirometer correctly?

I want to double check that I'm reading these respirometer vials correctly. The volume O2 of the following vials should be: Squirrels in Torpor: E1: 0.4 E2: 5.0 E3: 0.3 E4: 5.1 E5: 0.4 E6: 0 Squirrles ...
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1 vote
1 answer
59 views

exercise of gene linkage in genetics

Could you help me solve this problem: AAbbCC is crossed with aaBBcc and the offspring re-crossed with aabbcc. Considering that A and B are linked and their distance is 12 mapping units, while the gene ...
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0 votes
1 answer
109 views

Get "DNA" of one parent based on its children [closed]

I'm no biology expert so bear with me, but I've been given a task to estimate alleles of an animal based on the animal's children and the children's other parents. I've looked up Mendel's laws but I'm ...
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0 votes
0 answers
44 views

3 primers to know if Homozygous, Heterozygous or WT

In this imaginary experiment, I am using T-DNA to make an insertional mutagenesis that will get randomly inserted into the DNA where it might get inserted within a gene, disrupting it. In order to get ...
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-1 votes
2 answers
57 views

Cystic Fibrosis Genetic Risk Determination

Let's say Jane has Cystic Fibrosis and we know her brother doesn't. What are the chances of her brother's future child having CF? (The chances of Cystic Fibrosis in the general population can be taken ...
1 vote
0 answers
46 views

What are the advantages of long read sequencing for cancer oncogenomic research?

Currently I am using whole genome nanopore sequencing, Illumina short read and 10x linked read to study oncogenesis mechanisms of certain types of rare cancer. I am wondering about the advantages of ...
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0 votes
1 answer
69 views

Should I consider one or two DNA chains to find how many nucleotides are in a gene?

I am trying to solve an exercise. How many nucleotides does a gene contain if information about 287 amino acids is encoded in it? What is the molecular mass and length of this gene? AFAIK, I have to ...
-3 votes
1 answer
311 views

Primary function of cell wall is [closed]

A. Controlling volume B. Providing shape C. It's selective permeability D. Protection against bursting To me, all the given options seem correct except C. A and D are correct when the cell is placed ...
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5 votes
1 answer
263 views

A mutation question from the Indian National Biology Olympiad

DNA was isolated from wild type (Gal+) and mutant (Gal-) E. coli cells and separated by density gradient centrifugation technique. DNA from Gal- strain acquired a lower position. This indicates that ...
-1 votes
2 answers
83 views

Next Generation Sequencing False Negative [closed]

In Variant Detection, RNA-sequencing, and ChIP-sequencing, we showed how we matching, or aligning, short NGS reads to the genome, and then make inference using the reads which aggregate or "pile ...
0 votes
0 answers
74 views

Help identifying a part of a flower

I researched about floral diagrams and this is what I found:- This is floral diagram of Theobroma cacao. I managed to identify others but this part near the stamens was not found anywhere. Also the ...
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0 votes
1 answer
102 views

bunsen vs meker for best sterile field [closed]

I need one bunsen and i have a friend that sells me a bunsen-meker burner. I see that bunsen-meker burners have more flame diameter, so should have more diameter of sterile field, but i dont know XD ...
2 votes
1 answer
578 views

Is this question about limiting factors answerable?

This is from a Singapore-Cambridge GCE O-level Biology exam (a national exam for 16-year-olds). The exam board maintains that the question is "correct and accurate"—but isn't there a typo in ...
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1 vote
2 answers
48 views

Action potential attenuation in unmyelinated axons vs demyelinated axons

I learnt that action potentials travel much faster along myelinated axons, and when these axons are demyelinated the action potentials travel much slower and sometimes die out. Why do action ...
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0 votes
0 answers
84 views

my way of solving the biology question

Pure-breeding tall and pure-breeding short pea plants in the P generation were crossed as shown below. Based on the diagram below, one can assume that a)short plant height is the dominant trait. b)...

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