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.
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 ...
3
votes
1answer
194 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
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 ...
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 ...
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 ...
4
votes
1answer
936 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
854 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
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 ...
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
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 ...
4
votes
1answer
252 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 ...
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
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.
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 ...
1
vote
2answers
710 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 ...
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 ...
