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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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1answer
28 views

Water potiental

I think solution x should be present at Z as this solution has moved out of cell causing cell to be plasmolysed but the answer is Y. How?
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0answers
15 views

Apoplast pathway, down a water potential gradient or not?

So, I was doing a AS level MCQ, the question tells us that water passes across the leaf tissues by different routes as a result of 1) differences in water potential 2) the pull transmitted by ...
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0answers
29 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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3answers
1k views

What is the main general difference between Mitosis and Meiosis?

I found such a clause: The general principle is that mitosis creates somatic cells and meiosis creates germ cells. However, I cannot agree. Each gametogonium needs to go through mitosis before ...
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1answer
49 views

Do all restriction enzymes have palindromic recognition sites?

I am trying to find out the requirements for a segment of DNA to be the recognition site of a restriction enzyme. Acording to the article on Restriction Enzymes in Wikipedia, "many of them" (...
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0answers
21 views

My understanding of chromosomes and the processes related to them is lacking [closed]

I'm sorry for the incredibly simple question, I just can't seem to find any answers elsewhere online. I am a high school student currently studying for the upcoming AP biology exam, and recently I ...
1
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1answer
61 views

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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1answer
186 views

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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2answers
2k 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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0answers
21 views

The correlation between a leaf's age and its length in the initial stage of growth [closed]

I am building a machine learning algorithm which predicts the age of a leaf before its maturity period based on its measured length or area. I would like to know whether there is a mathematical ...
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1answer
46 views

Can anyone help me with these Biology evolutionary properties homework questions? [closed]

my teacher assigned these worksheet questions, they are ungraded, but he said something might come up on the test really similar to this so I really want to get all of them right. I am pretty ...
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0answers
14 views

Difference between Apo(a) and ApoA-I

I’ve been searching about apolipoproteinA-I and found some research papers about apolipoprotein(a). May I know if they are the same?
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2answers
17k views

Who are humans' closest relatives, after primates?

This question here addresses the controversy of whether humans are more closely related to bonobos or chimps. My question is - which group of animals are are closest relatives, beyond primates? Or ...
2
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1answer
46 views

Meaning of PAM matrix values

If PAM-1 matrix refers to time or evolutionary event for 1% change in amino acid sequence of a protein then how come there is PAM250? shouldn't PAM 100 be the highest where the two concerned sequences ...
15
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2answers
11k views

Solving Hardy Weinberg problems

I really fail to understand Hardy-Weinberg equilibrium and can't find an easy enough source of information. Can you help me to understand Hardy-Weinberg equilibrium? My goal is to be able to solve ...
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1answer
30 views

when you are to non-culturally detect the presence of E. coli in the soil from a cow pasture?

You are to non-culturally detect the presence of E. coli in the soil from a cow pasture. You do this by extracting the total DNA from a sample of the soil and PCR amplifying with E. coli-specific ...
0
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1answer
128 views

Is Protein-to-DNA ratio a good estimate of cell size?

I need help interpreting the result of an experiment. My class performed an experiment measuring protein concentration between heart, liver, and kidney tissue samples. The results were: Heart: 4.714 ...
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0answers
70 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 ...
2
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1answer
74 views

Why is a urea solution hypotonic relative to RBC?

If I place a RBC in 0.5M urea we see haemolysis. My textbook says that "the solution is hypotonic. Urea enters the RBC down it's concentration gradient. Water follows the movement of urea by osmosis. ...
2
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1answer
320 views

Genetics independent assortment?

As indicated in this question, what do you think is is the best explanation for the observed progeny, is it because distance between genes affects recombination frequency? My main concern is question ...
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3answers
111 views

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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2answers
4k views

Unsure about definition of “n” and “C” values in mitosis

I am preparing for a Biology exam and I'm reviewing the "n" and "C" notation used in mitosis. My professor said that when the cell replicates its DNA in S phase of mitosis, we get twice the "amount" (...
2
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1answer
128 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 $...
2
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1answer
89 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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6answers
27k 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 ...
0
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1answer
87 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 ...
1
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1answer
62 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 (...
2
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1answer
301 views

Drosophila grey / yellow

I am studying biology by myself via distance-learning. I have been trying to solve the following problem for a while now and hoped you could help me. As this is "homework" I would appreciate hints ...
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2answers
31 views

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 ?
5
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1answer
47k views

Chromosome and chromatid numbers during cell cycle phases

A diploid cell in G1 has 6 chromosomes. How many chromosomes and how many chromatids are present in each of the following stages? Here is what I am guessing G1: 6 chromosomes ; 6 chromatids G2: 6 ...
3
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2answers
4k views

Interpreting graph of mitosis and meiosis

Note : Consider the y axis as 1,2,3,4(not 2,3,4) and x axis as time. Roman numerals should be considered from I-X ( some are not correct here ) Which stages show mitosis? My answer : III-V Which ...
3
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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 ...
3
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2answers
100 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) ...
4
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1answer
13k views

How many cell membranes are oxygen and carbon dioxide diffuse through in the lungs?

In the lungs, oxygen and carbon dioxide pass through cell membranes by diffusion. Which row is correct? The correct answer is D, but I think it should be B. I can only think about three layers as ...
0
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1answer
83 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 ...
3
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3answers
88 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 ...
1
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1answer
70 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-...
5
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3answers
320 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 ...
3
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1answer
352 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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0answers
42 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 ...
0
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1answer
26 views

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 ...
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1answer
70 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 ...
1
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1answer
42 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 ...
2
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0answers
34 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 ...
0
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1answer
303 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 ...
3
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0answers
42 views

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 ...
2
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1answer
211 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
195 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
284 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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5answers
2k views

Punnett Square Help

In fruit flies, red eyes are dominant over white eyes. Show a cross between two white-eye fruit flies. My question is... How do I know if the white-eye fruit flies are homozygous or heterozygous?