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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probability of having normal daughter
If father has hemophilia, mother is a carrier of the disease, then
what is the probability of having a normal daughter ?
My question: Should the probability of having a daughter be also multiplied ...
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Probability of an $AABbCC$ offspring given the cross $AaBbCc\times AaBbCc$, is my solution correct?
So I have been working through the drills in the 26th edition of AP Biology Prep by The Princeton Review for fun when I came across this question in the Chapter 12 drill that I'm not really sure about ...
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Flow of left ventricle into the aorta
I am currently practising for an exam and am having trouble understanding one of the exam questions:
The table gives the blood flow rate in various parts of the fetal circulation.
Flow rate in mL min-...
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Calculating Possible Combinations of Bases in a DNA Strand of a Given Length
In my Biology class we were asked this question:
This DNA strand consists of eight pairs of nitrogenous bases. How many different sequences of eight bases can you make? Explain how you found your ...
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why does translation occur more frequently than transcription?
In our textbook it says that translation occurs more in a cell than transcription but I couldn't find anything that explains why it happens
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Evolution of Anoles
For context, I am currently looking at this virtual lab of Lizard Evolution by HHMI biointeractive.
Trunk anoles from an island called Iron Cay were placed in a few experimental islands filled with ...
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Is kranz anatomy not a defining feature of $C_4$ plant?
In NCERT Class 11 chapter 13 it is written that
The particularly large cells around the vascular bundles of the C4 plants are called bundle sheath cells, and the leaves which have such anatomy are ...
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Sucrose inhibits onion root mitosis? Why?
I am doing an experiment about the growth of onion roots.
I put onion plants in different solutions of sucrose in water — 0.1M, 0.2M, 0.3M, 0.4M, 0.5M — with the root touching the water.
Measurements ...
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Calculation of blood flow rate and pressure change in heart
Question: Blood flows from the left ventricle of the heart through the aortic valve and then to the aorta for system circulation. In a patient, the diameter of left ventricle outflow tract (LVOT) is ...
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Competitive inhibition - Similarity between substrate and inhibitor
I have this question -
Q. Competitive inhibitor which binds to the enzyme (a) has structural similarity with the product (b) is chemically similar to the substrate (c) has physical structure similar ...
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Why is it desirable to couple chemical production to growth?
I have the following question in systems biology:
a) Draw a graph showing the relationship of growth (Vbio) and Vefni for the system here. (Let the horizontal axis represent Vbio and the vertical axis ...
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Looking for literature that gives a systematic presentation of geometric and topological features of trees
Introduction
I am a software engineer specializing in procedural generation of 3D models, and currently I'm building a generator for 3D models of trees, founded on the theoretical work of Aristid ...
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Can a phenotype only have one allele?
A phenotype such as hair color
like blonde hair.
I am curious because mutations cause new alleles but does that mean that there always has to be a dominant or reccessive allele?
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What really is an allele?
My textbook says:
genes which code for a pair of contrasting traits are known as alleles.
Then that means T and t are alleles. Further, it says:
Mendel also proposed that in a true breeding, tall ...
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Inoculating agar plates with microbes suspended in sterilised water?
We were having a problem with our experiment (culturing microbes on homemade nutri agar) so we decided to change our set-up. It already cost us quite some money. So, we saw this procedure. Can anyone ...
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Is Natural Selection like a Copy Editor?
I am stuck on a Homework Question. It says:
Evaluate the following statement: “Natural selection works like a copy
editor; it works only with
what is already present in a population.” (Note: ...
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Why would it be impossible for gram-positive bacteria to store sulfur as gram-negative sulfur-oxidizing chemolithotrophs can?
I have a question that I am not sure what is the correct answer on <<Brock's Biology of Microorganisms>>
When the book introduces "Cell Inclusions", there was a mini-quiz that ...
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Identification of cells containing the gene of interest at a double strand break instead of undergoing recombination
If I tried to knock in a gene for example KANMX and want to swap it with say some gene "x", but, since, there can be double strand break in the DNA and KANMX may get inserted within the ds ...
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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 ...
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A level 2022 Biology percentage increase question [closed]
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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1
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Why do mutations in Drosophila dsx (double sex) affect both males and females?
Reason: Loss-of-function mutation of dsx gene in female embryo leads to production of a nonfunctional protein that fails to repress male specific gene expression. So somatic characters of both the ...
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Pedigree Analysis: Problem
I'm struggling to arrive at the answer to the following question, which appeared on a pre-test of mine and which I am now using to study the material we've learned. According to this helpful video, I ...
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Mammal size and capillary wall thickness
How does capillary wall thickness vary with the size of the animal?
Background/context of question:
Of the following, Figure 1 is most consistent with the fact that, in general, smaller mammals have:...
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Paternity testing using gel electrophoresis
When using gel electrophoresis to determine the father of a child, each band of the child must match with either the mother or the father. So half must come from the mother and the other half from the ...
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Genetics question on recombination frequency
A space probe discovers a planet inhabited by creatures that reproduce with
the same hereditary patterns seen in humans. The phenotypic characters are
height (T=tall, t=dwarf), head antennae (A-...
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Inferring mother's allele probability based on father and children
I am currently in the process of analyzing our family's genome. I do have access to his, mine and our father's genome, but not to our mother's (deceased). I was wondering how I could combine our 3 ...
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Nitrate fertilizer problem
Take the above problem. I understand how to do the calculation. However I can't seem to understand the units of the answer in the calculation.
The answers illustrate the units as t/ha^-2 which is ...
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Herbicide resistant crop plants
Consider the above multiple choice question. I can't seem to understand why the answer is B. How does genetically modifying the crop plant have any effect on the weeds?
The way I understand genetic ...
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What is the structure and function of chromosomes during interphase?
Ok, it seems to be easy but I have probably ignored something by accident.
Interphase is the phase where things are growing and the preparation for cell division happens. Its stages G1, S and G2. DNA ...
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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 ...
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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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Albino pedigree question
https://www.proprofs.com/quiz-school/playquiz/?title=pedigrees-quiz is a link to the website containing this question.
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Help with gene linkage and mapping!
Here's an interesting question I've been trying to figure out:
My annotations are in red. So far, I've figured out:
We know 630 colonies survived when plated with ACD antibiotics...meaning they ...
CommunityBot
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Question about Autosomal Recessive Alleles
I had a homework question that I could not figure out.
It states:
A woman has cystic fibrosis in her family and did not want to have a
child that suffered from the disease. She and her spouse ...
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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 ...
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1
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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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Nernst equation and equilibrium potential
Solutions A and B are separated by a membrane that is permeable to Ca2+ and impermeable to Cl−.
Solution A contains 10 mM CaCl2 , and solution B
contains 1 mM CaCl2.
Assuming that 2.3 RT/F = 60 mV, ...
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Why does the pH decrease, when adding pancreatin to different types of milk (cow milk, soy milk etc.)?
I'm experimentally observing how pancreatin affects the pH in different types of milk.
Why does the milk's pH decrease when I add an enzyme solution to different types of milk (e.g., cow milk, soy ...
CommunityBot
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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 (...
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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 ...
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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
...
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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 ...
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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? (...
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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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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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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 ...
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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 ...
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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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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 ...
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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. ...
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