11
votes
1answer
164 views

How big should the human population be, as predicted by body mass?

I would guess there is a theory in biology which states that the population size for a given species is inversely proportional to the body mass of individuals in that species. In other words, there ...
8
votes
1answer
196 views

Is our color vision calibrated to sky, vegetation, and blood?

Our color vision is based on three types of receptors (cones) which are sensitive to three distinct locations on the spectrum: 420–440 nm, 534–555 nm, and 564–580 nm. We label them "red", "green", ...
1
vote
2answers
108 views

human anti-mouse antibody

I have heard about human anti-mouse antibodies (HAMAs) and read that HAMAs neutralize murine antibodies, therefore decreasing the effectiveness of those murine antibodies. Is this true that HAMAs ...
1
vote
2answers
374 views

Why only female mammals have well developed mammary glands?

In course of evolution (possibly), mammary glands became vestigial in male mammals, but became fully developed in females. Is there any plausible explanation for this characteristic?
0
votes
0answers
30 views

Are there any mammals whose males can feed with milk? [duplicate]

Are there any mammals whose males can feed the offsprings with milk from the breasts?
1
vote
1answer
40 views

Flicker fusion threshold for insect eyes

I searched on bio-numbers for flicker-fusion threshold of insect eyes in general and for flies in particular. Ruck, 1961 gives values for some flies. Is there any database maintained for these values? ...
-1
votes
1answer
67 views

Can the same protein be represented by primary,secondary,tertiary structure? [closed]

As my book says: Protein can be represented by 4 structures. The primary structure represents the main chain and positions of amino acid residues. But actually, protein is not a rod but rather a ...
0
votes
1answer
271 views

What is the charge on oligonucleotide 5' pGpGpApCpT 3' at pH 7.00?

What is the charge on the nucleotide 5'pGpGpApCpT 3' @ pH 7.00? I thought adenine has 1 NH group and Guanine has NH and ...
3
votes
2answers
706 views

What does “chlorophyll photosynthesis peak” mean in relation to photon wavelength?

When reading about how green / leafy plants work, I saw that they have chlorophyll A & B, which allow the plant to use the energy from light by capturing and transforming. When reading about ...
2
votes
1answer
184 views

How to manage fat-gluten oxidation in celiac disease?

Assume you have been in non-gluten diet 20 years. You built mass 8 mass with substances containing gluten (endogenous gluten stored in fat). Then, celiac disease is diagnosed. You have been 3 ...
2
votes
1answer
68 views

Suggestions for self-studying experimental techniques

I would appreciate any suggestion regarding self-studying experimental techniques used in biology for a theoretical scientist (candidate). Maybe I should be more specific. I'm a biology major, but ...
-1
votes
1answer
87 views

To understand side-effects for nebivolol's beta1 selective pathway in PubChem? [closed]

Assume you have a drug nebivolol. When nebivolol is used as beta1 selective drug, beta2 is mostly for side effects, but this is not clear from PubChem. I do not know any cases where nebivolol is used ...
1
vote
1answer
74 views

Clonidine's adrenonergic nature?

I am little confused here. I used the term adrenoagonist and sympatholytic to describe the compound. However, my teacher says that the correct term here is adrenomimetic -term. My understanding of ...
3
votes
1answer
90 views

Molds and fungi usually found on book pages: identifying and preventing further spread

I know I can use bleach to kill most of the spores that live on my walls. I know I have to keep humidity below a certain level and temperature above another to prevent the spread of mold. I have read ...
2
votes
0answers
81 views

What are the common methods to estimate additive genetic variance?

Additive genetic variance can be estimated in a number of ways, and is a key concept in evolutionary biology and quantitative genetics. What are the typical methods (experimental designs) used to ...
2
votes
1answer
48 views

Change in synthesis rate of a molecule changes equilibrium concentration

I was reading the topic of 'The concentration of the molecule can be adjusted quickly only if the lifetime of a molecule is short' from Molecular Biology of the Cell by Alberts. At the end of pg-837 ...
2
votes
2answers
311 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 ...
1
vote
1answer
22 views

Determining break/border of movement

A population given inhabiting an area. I can trace every individual and I've got the hypothesis there is a break in distribution like individuals born in the upper half of the area will rarely move to ...
2
votes
1answer
61 views

What initiates primase to add an RNA primer to a DNA strand and what makes it stop?

What initiates primase to add an RNA primer to a DNA strand and what makes it stop adding RNA nucleotides? Is there tags added to the DNA back-bone?
3
votes
1answer
3k views

After vasectomy, where does the sperm go?

After vasectomy, where does the sperm go? Vasectomy Procedure cuts only vas deferens, But Our Testes still produces sperm, if there is no output for sperm, where does it go?
3
votes
1answer
288 views

What is the mechanism of action of lithium-induced polyuria?

I was reading in my pharmacology textbook on lithium in treating bipolar disorder, and I was curious to know if there was any specific action lithium takes to produce symptoms such as polyuria and ...
1
vote
1answer
2k views

How are lysosomes formed?

Lysosomes are irregularly shaped membrane bound organelles containing 50 different types of enzymes. But how are they formed? How are they produced??
2
votes
1answer
297 views

What is actually systematics? What is the difference between it & taxonomy?

In the last century, even during the past decades of the present century, students of systematics could not have thought of any fundamental distinctions among Taxonomy & Systematics . These ...
3
votes
1answer
130 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 ...
7
votes
1answer
2k views

Does THC excretion increase if urine volume increases?

In regards to the body metabolizing and excreting THC: if urination is increased as a result of drinking lots of fluids, does that mean that more THC is leaving the body? To rephrase the question, is ...
1
vote
1answer
100 views

Optimization of E. coli growth in D₂O (heavy water)

I would like to find a method of increasing the biomass of my D2O cultures because my current method is not yielding enough protein. I would like to also minimize the amount of H2O in my culture. My ...
2
votes
2answers
924 views

Viral Mutation Mechanism

I think I have a wrong concept about viral mutation process. First of all what is mutation actually? I mean, I know it's a sudden change in DNA, happening when subjected to mutagenic agents. But can ...
3
votes
2answers
1k views

Why do humans have only two nipples?

If other animals have more than 2 nipples, then why do humans have only 2 nipples? Even my pet dog has more than 2 nipples.
2
votes
3answers
517 views

Is there a stem cell/ biogel method exist for muscle and tendon lengthening?

Is there a stem cell/ biogel method exist for muscle and tendon lengthening? It is known that height surgery is limit to six inches with two surgeries and three inches each, it is also true that ...
0
votes
1answer
6k views

What is the exact chemical composition of human body? [duplicate]

I've just watched Breaking Bad Season 01 Episode 03. In that Walter gives the chemical composition of human body. The conversation is as follows Walter White: Let's break it down. Hydrogen. What ...
5
votes
1answer
508 views

Why does hair thicken and become more rough after a razor shave but not after one using a trimmer? [closed]

If a razor cuts only the hair, then how does hair thicken and become more rough with a razor shave and not after one using a trimmer? If both are used for hair removal, why is there a difference in ...
1
vote
1answer
82 views

What is different between the pigment of giraffes and the pigment of flowers?

I saw this video created by Derek Muller and he says there that it is very unusual to evolutionary develop the colour of the skin without the pigment. That sounds reasonable but if so, what nutrients ...
3
votes
1answer
81 views

B-cell and T-cell activation by parasites

Parasitic infections lead to the production of parasite-specific IgE, but they also lead to the activation of nonspecific, polyclonal B-cells and T-cells. How do parasites trigger non-specific ...
5
votes
1answer
852 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 ...
5
votes
3answers
300 views

Why do human ears have a lower boundary for the lowest energy perceivable signal than eyes?

I am currently hearing a lecture about human machine interaction. The lecturer is not a biologist (neither am I, we are both computer scientists), but he makes some statements about biology which I ...
10
votes
2answers
160 views

How Circumcision could reduce the chance for a HIV infection?

Circumcision removes the foreskin of the penis which mainly acts as a cover to the penis. Normally removing the foreskin makes more vulnerable to any STD, so how could circumcision reduce the risk of ...
1
vote
1answer
146 views

Henrietta Lacks and HeLa cells

Why did Henrietta Lacks die when her cells didn't die? As I understand it only the cells from her cervix were immortal so perhaps the cervical cancer took her life and the cells never died.
1
vote
5answers
2k views

How is incomplete dominance different from codominance?

Ok let me start with the definitions of incomplete dominance and codominance. incomplete dominance - The situation in which the phenotype of heterozygotes is intermediate between the phenotypes of ...
-4
votes
1answer
145 views

Are there any similarities in the DNA of a humans and animals? [closed]

As the title says, i've been wondering if there are any similarities between the DNA of humans and the DNA of animals? Like, maybe monkeys are more similiar in their DNA to humans, than dogs are (to ...
2
votes
1answer
48 views

Regarding the apoptosis mechanisms in cells and cancer

If all the cells in a cancerous tumour had their apoptosis mechanisms 'turned back on' or reactivated or repaired by some 'yet to be discovered' process would this cause the tumour to 'self destruct' ...
0
votes
1answer
16 views

About artificially induced processes that would normally cause a cell to self-destruct

Are there certain biochemical processes that would normally cause a cell to self-destruct but if the cell being tested has apoptosis mechanisms that have malfunctioned or been 'turned off' the cell ...
3
votes
1answer
309 views

Why are Merkel cells innervated by an axon, and not a dendrite?

Here are two images from Google. Afferent neurons receive input and send it to the central nervous system. Input is received by the neuron's dendritic end and send away centrally via axon terminals ...
1
vote
0answers
32 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 ...
4
votes
1answer
116 views

Does transplanted heart have full sympaticus without medication?

I am reading this and this where I am considering this sentence [N]o baseline parasympathetic innervation [in transplanted heart]. Does this sentence imply that the heart work then in full ...
2
votes
1answer
6k views

What is the difference between tonic and phasic firing?

I am reading about dopamine, and I have realized that dopaminergic neurons can fire phasically or tonically. What is the difference between these two modes of firing?
-2
votes
1answer
663 views

Bigger animals needs bigger amount of oxygen?

Bigger animals, like Elephants, or Dinosaurs for example, are in need for more oxygen than the amount of oxygen that small animals need? (humans, dogs, cats, etc) Thanks in advance.
2
votes
1answer
664 views

PCR processes number of amplicons produced [closed]

Beginning with 600 template DNA molecules after 25 cycles of PCR how many amplicons will be produced?
0
votes
0answers
53 views

Phenotype choice for one of a MZ twin pair in a genetic association study

I was having a discussion with a colleague and this question came up... It is commonplace in molecular genetics studies to only genotype one of a pair of monozygotic twins (and then implicitly impute ...
1
vote
1answer
103 views

Salbutamol's Pathways of Interaction and Classification

Salbutamol is a very commonly used direct-acting β2-agonist. This suggests me that it is sympatholytic. However, it has sympathomimetic pathways, see PubChem for Sympathomimetic. I am trying to ...
1
vote
0answers
16 views

Can different strains of Rhizobium share an infection thread or symbiosome?

Rhizobium infection can be triggered at root hairs of legumes, creating infection threads. Can these infections threads be colonized by more than one type of Rhizobium (e.g. Fixing and non-fixing)? ...

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