This tag indicates that the question is likely based on a home assignment in biology-related university or high school courses. Please see the homework policy on meta before asking homework questions.

learn more… | top users | synonyms

4
votes
1answer
32 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\ ...
2
votes
2answers
47 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 ...
0
votes
2answers
76 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
votes
1answer
45 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 ...
5
votes
2answers
247 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 ...
1
vote
1answer
37 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
votes
1answer
31 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?
2
votes
1answer
32 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 ...
1
vote
1answer
85 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 ...
1
vote
1answer
16 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 ...
4
votes
2answers
65 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 ...
1
vote
0answers
42 views

Infering the statistical tests performed in a paper [closed]

I am in great need of help in order to infer the statistical hypothesis tests performed in this paper (Xanthelasmata, arcus corneae, and ischaemic vascular disease and death in general population: ...
0
votes
0answers
18 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 ...
-5
votes
2answers
54 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
votes
1answer
53 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
49 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, ...
0
votes
1answer
13 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 ...
-2
votes
2answers
59 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 ...
3
votes
1answer
51 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
votes
1answer
41 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 / ...
-1
votes
1answer
38 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 ...
1
vote
0answers
25 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
vote
1answer
58 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 ...
0
votes
0answers
57 views

How do I determine the parental type here?

Please consider the following question: You cross Drosophilia and receive the following offspring: 965 wild-type, 944 black- vestigial, 206 gray- vestigial, and 185 black- normal. Explain your ...
0
votes
1answer
30 views

Quantitative Traits Genetics

Can someone please help with this question? I'm not so sure whether part A should be 11 inches or something else. Also, is part B correct
-1
votes
1answer
48 views

Bilayer synthesis? [closed]

If we want to design a bilayer from Myristic acid (14 carbon fatty acid). The average bond length between C-C is 1.5 A. What will be average thickness of the membrane? Edited to include the OP ...
0
votes
0answers
14 views

What are conditions for a membrane to be settled ? (centrifugation)

The cell membranes have 60% of proteins and 40% of lipids. And we know that medium density of proteins is 1,2 g/cm3 and the medium density of lipids is 0.92 g/cm3. How can we calculate the medium ...
0
votes
1answer
32 views

Dimensional analysis Question

So I'm new to the dimensional analysis world and I'm little confused and the answers I'm getting are not convincing :( if the concentration of hemoglobin in a 5ml sample of blood is 34 g/dL. and red ...
1
vote
2answers
143 views

How much of your stock solution should you take to make the 1000 cells/mL mixture? [closed]

You need a solution containing 1000 buccal cells/mL. You count that you have 125 buccal cells in 50uL, from a total solution of 8 mL. How much of your stock solution should you take to make the 1000 ...
1
vote
0answers
23 views

Neuroscience: zapping an axon connected to thermoreceptor

Let’s say an experimenter has an electrode that can give a shock to a single axon. She takes that electrode and zaps an axon connected to thermoreceptors in the hand of her subject. I) What would the ...
0
votes
0answers
20 views

spinal cord lesion and result in somatic sensation

Jimbo suffers a lesion to the entire right half of the spinal cord at the T6 level. A few weeks after his injury, his doctor tests his right and left legs for somatic sensation and tone. fill out her ...
1
vote
1answer
88 views

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: ...
1
vote
1answer
42 views

What is ischaemia exactly?

I think it is decreased blood supply to organs and tissues. I also think it is the stopped circulation. However, both ones cannot be right, I think. What is ischaemia exactly?
2
votes
1answer
31 views

What can thrombosis lead to?

I am thinking this question. Thrombosis can result in organisation of thrombus, sepsis thromboembolism, fibrinoid swelling adiposity. I fibrinoid swelling (edema) (4) can occur. Also, I think (3) ...
2
votes
1answer
38 views

Lytic Viruses — Cell lysis?

So in the video my instructor sent on viruses, he said that for lytic viruses, new viruses manufactured by the host cell could get out of the cell in one of two ways. The new viruses would leave by ...
0
votes
0answers
16 views

Southern/Western blot analysis and pedigree diagram? Help needed. [duplicate]

Hello everyone. I urgently need help with this question please. I have filled in the blanks using the results in the figure provided in the sheet. However, for number (b) is a little hard to ...
1
vote
1answer
36 views

Gene Complementation Question

Hi everyone! Here is a diagram of a genetics complementation problem. My main concern is regarding number 3d. I'm assuming that in this case, it would be complementary interaction and thus ...
2
votes
2answers
172 views

Promoter in the lac operon

Here is the question: Suppose an experimenter becomes proficient with a technique that allows her to move DNA sequences within a prokaryotic genome. If she moves the promoter for the lac operon to ...
1
vote
1answer
65 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 ...
5
votes
2answers
1k views

How do we know that everybody's DNA fingerprint is unique?

How do we know that everybody's DNA fingerprint is unique? I know, I know, everybody's DNA is unique. But when we do DNA fingerprinting, we're looking at very specific regions of high variability. ...
0
votes
0answers
36 views

Gene linkage/mapping

I need some help with this question in the image posted. As you can see in the instructions, I'm asked to map the genes. So the first thing I did is write out the alleles corresponding to each ...
0
votes
1answer
69 views

Gene pool simulation [closed]

this simulation, you sampled the gene pool without replaceing beads in the beakerafter you drew each one. Thus, f(A) and f(a) in the gene pool changed slightly after each bead was drawn. For example, ...
-1
votes
1answer
38 views

calculate the number of heterozygotes [closed]

The ability to taste PTC is due to a single dominant allele "T". You sampled 215 evolution students, and determined that 150 could detect the bitter taste of PTC and 65 could not. Assuming this trait ...
1
vote
1answer
31 views

What are the best detection medias for cholera?

I heard this fact that you can use some [hypertriade] for vibrio cholera diagnosis which has compontents sucrose (yellow) mannose (yellow) arabinose (do not ferment; stay dark pink) I did not find ...
0
votes
2answers
84 views

What is the right spelling for this agar? [closed]

I could not spell the agar [gonoline-uroline] which I heard yesterday. My spelling is so wrong that I could not find it in Google. What is the right spelling for this agar?
0
votes
1answer
87 views

Pathway mediates nitroglycerin-induced relief from angina pectoris [closed]

what kind of Pathway mediates nitroglycerin-induced relief from angina pectoris,please provide some idea...
0
votes
2answers
88 views

DNA sequence from the middle of a gene

Someone gives you a short DNA sequence that comes from the middle of a gene. 5'- TCTAACTGATTAGC -3' 3'- AGATTGACTAATCG -5' From this sequence, determine the ...
0
votes
0answers
81 views

Genetic Linkage/Mapping question Help

Hello everybody! I need some help with this question in the image posted. As you can see in the instructions, I'm asked to map the genes. So the first thing I did is write out the alleles ...
1
vote
1answer
102 views

question about directional selection

Cattle breeders have improved the quality of meat over the years by which process? A) artificial selection B) directional selection C) stabilizing selection D) A and B E) A and C I know the answer is ...
0
votes
1answer
57 views

vestigial structure question

If a species has a vestigial anatomical structure that it no longer uses, would you expect this structure to disappear over many generations through the action of natural selection? Always, sometimes, ...