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What is a Good Essay Question for Photosynthesis? [closed]

I'm a freshman in highschool, and we have a test on photosynthesis coming up next week. I was wondering what a good, all-inclusive essay question, that will cover the processes of light-dependent ...
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1answer
27 views

PCR cycle problem [closed]

IF I began a PCR cycle with 5 copies of a particular DNA section, and copied the section by PCR, for 6 cycles, how many copies of the DNA (include the originals) would I have by the end of these ...
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1answer
21 views

Intro Bio question: dihybrid punnet square

Today we had our exam. There was a punnet square for two genes. and when I multiplied , for example, Ry × rY I wrote the answer as ...
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1answer
42 views

Simple Mendelian Genetics Question

here is my question: In certain plants, tall is dominant to short. If a heterozygous plant is crossed with a homozygous tall plant, what is the probability that the offspring will be short? My ...
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1answer
41 views

Problem on number of amino acids that an alien can use

A new life form discovered on a distant planet has a genetic code consisting of five unique nucleotides and only one stop codon. If each codon has four bases,what is the maximum number of unique amino ...
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0answers
8 views

Why is the storage ring of a synchrotron vacuum? [migrated]

I know that when the particles accelerated gets to the storage ring they loose energy releasing the synchrotron light but how does the vacuum make it loose energy ? Does it slow it down, increase, ...
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1answer
53 views

Restriction Mapping - Homework question

I have trouble in solving this exercise. Exercise A circular plasmid of 10,000 base pairs (bp) is digested with two restriction enzymes,A and B, to produce a 3000 bp and a 2000 bp bands when ...
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0answers
13 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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2answers
31 views

T-cells Question

T-cells are important for efficient vaccination since they have: A. T-cell receptor (TCR) B. CD4+ C. CD8+ D. Memory My gut is telling me it's A since the TCR would recognize the antigens but I ...
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1answer
53 views

Calculating number of amino acids in mRNA

Assuming there were 20 different amino acids and less than 40 types of different tRNAs found in this alien organism. How many amino acids would be found in the translational product of a ...
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1answer
53 views

What is meant by “genes involved in the stress response”?

I would like to know about the term stress response. For example "some genes of a species under study is involved in stress response". What does that mean? I got this as a part of my assignment ...
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1answer
57 views

Hardy Weinberg problem help!

The three common genotypes at the hemoglobin locus have very different phenotypes: SS individuals suffer from severe anemia, AS individuals have a relatively mild form of anemia but are resistant to ...
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0answers
16 views

Physiological function of CFTR gene product? [duplicate]

I just need a clarification. If I am to talk about the physiological function of the CFTR gene product? Then what should I do research and talk about? The only physiological function that I can ...
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0answers
30 views

Finding appropriate research papers? [on hold]

I had previously asked some question on cystic fibrosis and I had mentioned that I am a senior in high school writing a paper on gene therapy and CF. I would like to some specific paper on viral ...
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0answers
23 views

Gene Therapy for Cystic Fibrosis Extension [closed]

Thank you everyone for answering my previous two questions on CF. I have decided to write a paper specifically on the use of viral vectors and gene therapy for cystic fibrosis. I was told by my ...
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2answers
252 views

HIV and effectiveness of inhibitor cocktail over single inhibitor

I'm looking for clarification on the answer to this question. It's in my biochemistry class but I figured this is more Biology than Chemistry, so I'm asking it here. The question is: One of the ...
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1answer
43 views

Understanding intra and extracelullar concentrations (membrane potential)

I have 4 question (not homework) What happens to the cells membrane potential if: a) Na+ outside rises by 40mM b) K+ inside rises by 10mM c) K+ outside rises by 10mM d) A- (impermeable ion) ...
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1answer
72 views

Interpretation of graph from evolutionary biology

I am studying evolutionary biology, and been presented with this graph: I am having some difficulties understand its meaning. For a start, why is time measured as a fraction of the population size? ...
3
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1answer
85 views

How does electrolarynx work?

I have heard that this is an effective replacement for patients who have a dysfunctional larynx, partly due to cancer. I am curious to know the inner working of this device and why such a robotic ...
2
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0answers
73 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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2answers
109 views

are the spontaneous generation and evolution the same idea but in a different time scale?

I was in my biology class, learning the history of spontaneous generation and how this idea was discarded. I told my teacher that is the same as evolution but in a different timeline. I Argue that ...
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1answer
111 views

Answer the questions in one word with help of clues and images given [closed]

Name the things associated with Antonie Van Leeuwenhoek - (6 pictures are given for help and four of them are associated with these clues) a)Leeuwenhoek was the first to describe these and hence ...
2
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1answer
100 views

Which process is needed to complete male reproductive development?

In order to properly complete male reproductive development: ...
0
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1answer
73 views

What is the importance of hydrogen bonds in water? and other questions: [closed]

These are extremely simple questions — basic biology — but I would like to make sure that the way I have answered is at the very least correct. Hydrogen bonds are very weak, so how is it possible ...
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1answer
45 views

How to measure the total number of cells in an average human body?

I have got one assignment to calculate the approximate sum total of all cells in the human body. How to tackle this problem? I know that the current statistics is $10^{13}$ cells. I wanted some hints. ...
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1answer
69 views

How to estimate the DNA density in human sperm head? [closed]

I have got an estimate of sperm head volume from internet.Like consider it as a disk of order 4-5µm. Now I wanted to find the DNA density in the sperm head. How to find that?
3
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0answers
56 views

A Genetic linkage problem [closed]

I have recently switched from electronics to computational biology. So having some hard time with my homeworks. Can someone guide me on this problem? Consider 6 genes A, B, C, D, E, F, G. Some ...
4
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1answer
51 views

Microbial Fuel Cell Reaction

I found a formula online which explained the reaction which occurred in the anode chamber of a microbial fuel cell but there was a typo $\small NADH + Ferredoxin_{(ox)} (NADH-Ferredoxin\ ...
4
votes
1answer
131 views

which signalling pathway is involved in cancer?

Columnar epithelial cells from the colonic mucosa are studied to identify abnormalities in cell signaling pathways. Abnormal epithelial cells from colonic adenocarcinoma are shown to have a mutation ...
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2answers
96 views

alpha tubulin molecular weight problem

Is there any academic reference that shows α-tubulin is around 50-55 kDa? The only thing I found is some data sheets from companies. I need the real reference.
4
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1answer
75 views

Epistasis Involving Multiple Loci

The following problem is from Schaum's Outlines on Genetics, 5th edition, by Elrod and Stansfield. I'm having some trouble solving it. It is found under a section entitled "Interactions with Three ...
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2answers
928 views

Diffusion of Hypotonic solution into solution with glucose and starch

Cell walls are selectively permeable to ions and organic molecules. Sometimes the selectivity is passive and a reflection of the physical laws governing diffusion. We can do simple experiments that ...
0
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1answer
67 views

Question about what the liver does NOT do

Which of the following functions is NOT performed by the liver? a) Storage of vitamins and minerals b) converts glucose to glycogen c) converts toxins to harmless chemicals d) produces bile I chose ...
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1answer
45 views

Conclusions from hybridization results

A double stranded DNA was denatured in a mixture that included mRNA from a gene in the segment. The mixture was then cooled to promote RNA and DNA hybridization. The following figure the results. ...
2
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1answer
33 views

What are the criteria for determining the origin and end of muscle anatomically?

For example the pectoralis muscle starts from sternum region and ends on the acromion or coracoid process. Why you can't say that it starts acromion process and ends on the sternum?
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1answer
36 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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1answer
133 views

Transverse diffusion of lipids in red blood cells

The membrane of a human erythrocyte has polarity: Phosphatidylethanolamine and phosphatidylserine are predominantly on the inner side. Phosphatidylcholine and sphingomyelin are predominantly on the ...
2
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1answer
18 views

Question regarding 2 constructs of tobacco plant

Six independent transformation experiments of tobacco leaf explants were carried out using two different constructs - (1) construct I containing only a Hygromycin-resistance gene $(HYG^R)$ as a ...
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3answers
105 views

Membrane potential after exposure to glutamate

Neurons were kept in a physiological solution. During the resting phase, the membrane potential in the axoplasm of neurons was negative compared to the extracellular space and a potential ...
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0answers
34 views

Hypothalamic breakdown and effect of temperature on membrane lipids

I'm in my last year of high school and doing a research assignment on thermoregulation. In the excellence level exemplar for the standard, a student made the statement: Once the body's internal ...
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2answers
76 views

How are atoms created? [closed]

From small baby to the old age, we will be grown. We are composed of bunch of atoms, multitude of atoms. When you are grown from baby to the teen age, everyone will say "he has grown!" What do you ...
3
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1answer
68 views

Amino acid profile of GPCRs

You are studying cellular signalling through a newly identified GPCR. Specifically you’re working on a pair of newly identified GPCRs, GPCR-A and GPCR-B. Each binds the same small ligand, but ...
2
votes
1answer
88 views

tetrads in meiosis are held together by what

This is from SAT subject biology test practice question. The answer it gave me was both chiasmata and centromeres. I can understand they are held by chiasmata but why also centromeres? I looked it up, ...
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1answer
19 views

What is Saccus in Embryology?

The word seems to be of German origin. I have it here Saccus lymphaticus inguinalis, Saccus lymphaticus jugularis, Saccus lymphaticus posterior, Saccus lymphaticus retroperitonaealis. I ...
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votes
1answer
108 views

Punnett square and hybrid cross [closed]

A plant breeder crossed two plants, one with red flowers, and the other with white flowers. Red is dominant. Calculate the phenotype and genotype ratios of the F2 generation of this cross. Is this a ...
4
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1answer
55 views

relative-rate of evolution

I am supposed to calculate the relative rate of evolution of two sequences (human and sheep) with a chicken serving as the outgroup. The sequences are pretty long, so I will just create a short ...
0
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1answer
65 views

Possible Genotypes — Linked Genes

Please consider the following question: Genes A and B are located on the same chromosome. If two individuals with the genotype shown below are crossed, which genotype could be formed? Let / ...
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1answer
49 views

What is this abbreviation CT in female reproductive system [closed]

I have this sentence in my notes Ovary is surrounded by tunica albuginea and the cortex keeps the primordial follicles. The medulla containing CT and blood vessels develop from mesonephros. I ...
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0answers
37 views

Codominance and Partial dominance [closed]

The following genetic tree is given regard the fur color of some animal. The color determined by one gene that have two alleles and 3 genotypes: black, white and inlaid. I've been asked to ...
1
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1answer
67 views

Population Genetics Question

Can someone please help with this question? Here is my working (just in case it is not clear: 1/300*1/30*1/2) but is this actually correct or do I need to multiply by 0.5 once again? I appreciate ...