This tag indicates that the question targets some basic concept or information that might seem trivial to professionals and can be seen as a home assignment in biology-related university courses. Please see the homework policy on meta before asking homework questions.
15
votes
3answers
138 views
What is the optimal frame size for protein secondary structure prediction methods?
The whole question is
What is the optimal frame size for the second and third generation protein secondary structure prediction methods? Justify your answer.
I remember it has something to do ...
7
votes
1answer
138 views
Finding DNA from Amino Acid sequence problem
My attempt: First I took the single letter AA codes and made them amino acids. So, the first one is Trp which is 5'-UGG-3'. From this I got the DNA sequence 3'-CCA-5'. However, the correct ...
6
votes
2answers
437 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 ...
6
votes
1answer
124 views
Effect of histidine on the binding affinity of HisP
I was asked the following question by my teacher:
A gene regulatory protein called HisP regulates the enzymes for
histidine biosynthesis in the bacterium E. Coli. HisP is a protein
whoes ...
6
votes
1answer
294 views
What forms the human amniotic sac?
I am trying to understand the formation of embryonic disc for human and chick so the following question is related to here about formation of embryonic disc.
I had thought that the amniotic sac forms ...
6
votes
1answer
197 views
To understand why satellite cells are genetically inactive in Barr body
DAPI is used as a stain for DNA heterochromatic and euchromatic regions. The Barr body is heterochromatic.
In the slide of a normal human female cheek's somatic cells, there is apparently no other ...
6
votes
1answer
94 views
How does Topoisomerase II inhibition affect cancer cells?
Topoisomerase II poisons represent some of the most important and
widely prescribed anticancer drugs currently in clinical use. These
drugs encompass a diverse group of natural and synthetic ...
5
votes
1answer
349 views
Genetic carrier Pedigree of Recessive Traits
A human male and female couple with normal colored ears discover that, in both of their families, their fathers (who have normal ears) each had siblings with red ears. Red ears is a rare autosomal ...
5
votes
1answer
115 views
When does Coelom form exactly?
Related to my other question.
I know that the coelom is derived from mesoderm.
Coelom seems to form during organogenesis within 3rd and 8th week of embryogenesis.
However, that answer is not either ...
5
votes
1answer
85 views
What is the total number of rounds of cleavage during mammalian embryonic development?
That for frog is 12, but what about mammalian embryos?
I cannot find the exact number anywhere.
4
votes
2answers
89 views
Difference between biological control and introducing species for conservation?
I have a biology assignment and we have to explain various methods and strategies for conservation, two of which are:
Biological control
Introduced Species
What is the difference between ...
4
votes
1answer
37 views
How do fibers control muscles?
My professor says
Nervus troclearis IV somatomotor fibers supply musculus obliquus superior.
and similarly for nervus oculomotorius III
Nervus oculomotorius postganglionic fibers supply ...
4
votes
2answers
416 views
What are the advantages and disadvantages of using beta-galactosidase compared to luciferase as a reporter gene?
In the University labs, we have used Beta-galactosidase as a reporter gene to quantify the expression initiated by the stress-response promoter in yeast. This was done by exposing one of the two ...
4
votes
1answer
94 views
Finding exons in DNA problem
My attempt: I looked for the TACs because I thought this would be AUG in mRNA and ultimately Methionine (the start codon). But apparently, that's not how you do this problem. Im confused because ...
4
votes
2answers
4k views
Does Human Female Meiosis II occur after fertilization with sperm?
I am reading the answer and I am getting confused by the sentence:
At the end of meiosis I females have two daughter cells and meiosis II
only occurs if and when fertilization occurs by a sperm ...
4
votes
1answer
210 views
What is the largest perennial herbaceous plant?
What is the largest perennial herbaceous plant? My guess would be some kind of banana or bamboo.
4
votes
1answer
932 views
Do humans have Coelom?
Kimball Biology 5e says
Coelom is the main body cavity of many animals. It is lined with an epithelium derived from mesoderm.
Gilbert Embryonal Biology 9e says
Coelom is the space between ...
4
votes
1answer
42 views
Parsimony (cladistics)
I don't understand how to sum the changes in a phylogenetic tree.
Here for example: http://www.med.nyu.edu/rcr/rcr/course/phylo-cladistic.html
How do you end up with 8 for the first and 9 for the ...
4
votes
1answer
850 views
What are differences between formation of embryonic disc in chick and mammal embryo?
Exam question which got lowest average points in my university: 1/5 average.
No markscheme available so my attempt below.
I assume that embryonic disk prefers to germ disk such that Formation prefers ...
4
votes
0answers
41 views
Determine which gene is in the middle complementation [duplicate]
Possible Duplicate:
Crossing mutant strains on minimal media problem
I'm studying this problem for my genetics final:
My Attempt: The answer for part B is met2 and the answer for part C ...
4
votes
1answer
251 views
Does Amphibian embryo's blastocoel become a primitive yolk sac without yolk?
The mammalian blastocoel becomes yolk sac without yolk according to my professor. I have not found any evidence that such a thing happens in amphibians like frog.
I need to be able to compare and ...
3
votes
1answer
240 views
What are all possible vectors for unicellular human parasites?
I got the given question. They want the following pieces of information about protozoological human parasites:
disease - parasite - vector.
There are 10 proteogenic diseases at the Wikipedia. I ...
3
votes
1answer
159 views
Does chicken embryo form the disc called “discoblast” in the cleavage and blastulation of chicken?
This thread is related to my previous thread which is still unsolved mainly. I need to be able to compare chick and human cleavage and blastulation of zygote.
My friend says that
Chicken have ...
3
votes
1answer
4k views
What factors affect the rate of transpiration in plant leaves?
I'm trying to get my head around factors which affect transpiration in leaves.
For example, how would applying petroleum jelly to the surface of plant leaves affect their rate of transpiration?
I ...
3
votes
1answer
136 views
Predicting progeny of recessive mutations using recombination
I was asked this question on a test and got it wrong, but I'd like to know how to do it. The answers are shown in the blanks below:
You are studying two recessive mutations in the fruit fly D.
...
3
votes
1answer
3k views
Pedigree Probability of Autosomal Recessive Trait
Here is a pedigree:
The trait is autosomal recessive.
The question is: What is the probability that the bottom 2 people (4 and 5) have a child with the trait?
I tried doing ...
3
votes
1answer
454 views
Is secondary follicle or Graafian follicle arrested in the second metaphase of oogenesis?
My note about which I am not sure:
Secondary oocyte is arrested in the metaphase II monthly after puberty until fertilization with sperm.
The following picture also satisfies my sentence: .
So ...
3
votes
1answer
193 views
Where does meiosis II of oogenesis end exactly in tuba uterina - uterus?
I know that metaphase II ends at ampulla tuba uterina, but I am not completely sure where the telophase II ends. Is it in the triangular section of cervix uterii?
I just have an intuition that the ...
2
votes
2answers
889 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 ...
2
votes
2answers
115 views
Translate DNA to Protein
Assuming the sequence shown is read left to right, what is the sequence of the protein produced?
sequence: 5’-ATGTACTTCCATCTGGAATAG-3’
MY ATTEMPT: I know RNA is synthesized 5 to 3. This is ...
2
votes
1answer
255 views
Is Aspergillus clavatus an unicellular organism?
I could not find the piece of information form Burton Human Parasitology -book and not by Google.
Yeast is divided to two phylums: one of them is Ascomycota.
Aspergillus clavatus belong to the given ...
2
votes
2answers
74 views
What is the purpose of measuring both VS (volatile solid) and TS (total solid)?
In the biogas process you often measure Volatile solid and Total solids. Can any one explain these concepts more accurately and why it is interesting to look at these properties.
The biogas process ...
2
votes
1answer
60 views
Substrates of cytochemical reactions in this immunostaining
Expression of extracellular protein Laminin 9 alpha-4 chain in human skeletal muscle.
Indirect immunostaining with HRP immunostain marker. Ob.x40.
I have unsuccessfully searched NCBI -database, JSTOR ...
2
votes
1answer
60 views
What causes tree lines?
There is an area of where there is a distinct line of only trees on one side and only shrubs on the other (right next to each other). What could cause this?
My attempt: I said there could be a ...
2
votes
1answer
196 views
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 ...
2
votes
1answer
30 views
What range of dose should be used?
This is a dose-response experiment testing a new cancer drug. the darker line represents cancer cells. what range of dose should be used? I think it's 2-4 because this affects cancer cells only. is ...
2
votes
1answer
145 views
What happens to colloidal particles in a liquid medium? And how to stabilize it?
Definition
Colloid is a dispresion of small particles of one material in another.
Definition 2 (Wikipedia)
A colloidal system consists of two separate phases: a ...
2
votes
1answer
51 views
Hardy-Weinberg Equilibrium: To compute probability of finding two siblings (random mating)
I've been working a little with M. G. Bulmer's Principles of Statistics (Dover, 1979) and cannot see how to properly compute half of one question. This should be a basic probability computation, but I ...
2
votes
1answer
67 views
Are there any organisms with larva more advanced than adult form?
Usually adult organisms are more sophisticated than corresponding larva, i. e. frogs, mosquitoes, fish. Are there species where the opposite is true?
2
votes
1answer
97 views
Why are Birds and Reptiles with abundant yolk sac polyspermic?
I was given an explanation that birds and reptiles are polyspermic because they have an abundant yolk sac. But how does it explain the thing?
Chicken as an adult is not using in my opinion yolk as an ...
2
votes
1answer
55 views
Does this patient have HHV6 or HCMV after transplant surgery?
I have been given mock results from a PCR test on blood samples taken from kidney recipient patients and their donors. The PCR reaction can detect single copies of viral DNA. I have been asked to ...
2
votes
1answer
37 views
Similarities Between Cells?
Which of the following are usually identical between a lung cell and a brain cell, from the same person, assuming that they are normal (non-cancerous) cells? Circle your choice(s).
...
2
votes
0answers
73 views
Mouse meta-globin mRNA problem
This is an mRNA strand of mouse meta-globin:
5'-ccccagauacggaauucgaau-3'
A) Which small RNA (below) is most likely to regulate expression of
meta-globin?
...
2
votes
1answer
326 views
What does entering of sex chromosomes to gametes mean during meiosis I?
I am reading one answer about meiosis:
During meiosis I, the sex chromosomes separate and enter different
sperm or egg cells (gametes).
I assume that sex chromosomes refer here to homologous ...
1
vote
1answer
55 views
Two brown-haired people have two children, P and Q. P has blond hair. Q has brown hair. What is the probability that Q is heterozygous?
Two brown-haired people have two children, P and Q. P has blond hair. We therefore believe that each parent is heterozygous and that blond hair is a recessive trait.
Q has brown hair. What is the ...
1
vote
1answer
47 views
At what substrate concentration will an enzyme work at 40% of its maximum rate if its Km = 0.095M?
The question involves the Michaelis-Menten kinetics equation.
Here is what I did: I took the Michaelis-Menten equation, replaced v with 0.4Vmax, canceled the Vmaxes (one on each side), and solved ...
1
vote
2answers
1k views
Restriction Mapping of Plasmid Assignment
pUWL22 is a circular, double stranded, 10.5 kb plasmid. It contains a
gene encoding an enzyme that confers ampicillin resistance in the host
bacterium. Cloning into the kpn I and Sst I sites ...
1
vote
2answers
703 views
What is the Giemsa staining of chromosomes?
I got the question in my exam and wrote the following and I do not understand what is wrong in it:
Giemsa staining is a staining method to stain particularly malaria and other parasital diseases. ...
1
vote
2answers
65 views
Will climate change affect flower population?
There is a flower population elevated 1000 meters above sea level. If climate change causes a 12 degree C increase in temperature over the next 10 years, what will happen to the flowers?
1
vote
1answer
50 views
Which cells will pass cancer to offspring?
Each of these types below contains a DNA mutation. Which type(s) will affect the children of the individual whose cell it is.
...
