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.
4
votes
1answer
880 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 ...
6
votes
1answer
125 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 ...
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 ...
3
votes
1answer
250 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 ...
2
votes
1answer
265 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 ...
5
votes
1answer
353 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 ...
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 ...
6
votes
1answer
308 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 ...
3
votes
1answer
168 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
200 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
1answer
200 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 ...
4
votes
1answer
979 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 ...
5
votes
1answer
116 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 ...
4
votes
1answer
257 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 ...
1
vote
1answer
138 views
Is this mammalian embryo blastocyst, gastrula or only phase between them?
The picture shows the formation of early blastocyst and late blastocyst.
The middle embryo has embryoblast.
My professor says that blastocyst in general has embryoblast and trophoblast.
Embryoblast ...
2
votes
1answer
332 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 ...
4
votes
1answer
212 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.
6
votes
1answer
200 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 ...
1
vote
2answers
747 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. ...
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 ...
