Questions tagged [definitions]

Questions looking for clarifications or definitions of biological terminology.

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2
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1answer
35 views

About the definition of ketogenic amino acid

I am studying biochemistry and have been looking at metabolic network diagrams showing the different intermediates of glycolysis and the citric acid cycle that amino acids can be converted to. I have ...
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9 views

Can PGPM include pathogenic growth promoters?

I am extremely confused with definition of P.G.P.M. (plant growth promoting microbes/microbiota)such as P.G.P.F (plant growth promoting fungi) and P.G.P.B. (plant growth promoting bacteria). In many ...
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1answer
24 views

How to define ammonites?

I miss the definition of ammonite. In my opinion, many authors confuse the term "Ammonite" and "Ammonoid". Ammonoids (Ammonoidea) are large group of cephalopods including for example goniatites (...
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57 views

What is the difference among biochemistry, molecular biology, molecular genetics and structural biology?

I have never heard of straigthforward definitions of these fields in my college lectures, and the Internet searches were not very helpful. However, from what I have learned at different subjects, this ...
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1answer
40 views

What does “crude” mean in this context?

Taken from Ian Freshney's Culture of Animal Cells: The enzymes used most frequently for tissue disaggregation are crude preparations of trypsin, collagenase, elastase, pronase, Dispase, DNase, ...
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1answer
103 views

Is this model of understanding of what's natural selection and what's not, correct? [closed]

Here in this account I just want to make sure, that I've grasped the concept of natural selection as is usually spoken by evolutionary biologists, truly the wording here are non standard and in some ...
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4answers
2k views

What is the definition of “Natural Selection”?

Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. Natural selection, a process that results in the adaptation of an organism to its ...
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1answer
51 views

Actual definition of cardiac output

Is cardiac output the amount of blood pumped by both ventricles in 1 minute or only by the left ventricle in 1 minute?
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1answer
40 views

Is studying chemical and physical properties of chemical substances that make up organisms really a task of molecular biology?

I have read in a high school textbook that (translated into English by myself): "Branch of science that concerns itself with studying chemical and physical properties of substances that make up ...
2
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1answer
755 views

What is the difference between a cytokine, a hormone and a protein hormone?

I'm trying to figure out the difference between hormone, cytokine and protein hormone. It's clear to me that all three are biological messengers, but there seems to some ambiguity and overlap between ...
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0answers
53 views

What function will survive evolution?

I wrote the following phrase in my scientific text: X is ubiquitous in life of Y. On some occasions X might be detrimental, resulting, for example, in so so phenomena. But is it plausible that a ...
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0answers
29 views

What is a section in botany based upon?

I am a bioinformatician working with plant data. Therefore my formation on plant biology and botany is "ok" but not very strong. When people talk about sections, I know that they talk about a ...
2
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1answer
553 views

Introgression vs admixture

What is the difference between genetic introgression and genetic admixture ? Are these terms interchangeable ? Do they apply to different population scopes or something ? The usage seems kind of vague ...
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1answer
60 views

How do you define a gene list?

So I wrote in a chapter that I will be checking for publications with gene lists in them. I got a comment asking "How would you define a gene list and what criteria did I use". I know that gene lists ...
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1answer
286 views

Usage of “lineage” over “species”

Remi.b has suggested here: The concept of species is poorly defined and is often misleading. The concept of lineage is much more helpful. IMO, the only usefulness of this poorly defined concept ...
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1answer
27 views

What do the column labels in this table mean?

This table shows the effect of sound (song and tones) on female birds. However, I'm not sure what the labels (F1 22, P and η2) mean. I've seen the labels on other tables too. (from https://www.ncbi....
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3answers
142 views

Evolution as a directed graph exploration?

First of all, I am not biologist, nor good in chemistry/physics. Secondly, I am really eager to understand. So I think of a "life" (of a certain whatever being) as a space of somewhat properties. ...
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108 views

Why is a cellular structure necessary to satisfy the definition of alive? [duplicate]

I was looking at this image and reading through the Wikipedia page for viruses and it says that to satisfy the definition of "being alive" the organism must have a cellular structure, but it seems to ...
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3answers
632 views

Can domestic breeding be considered evolution?

Domestic breeding of animals (and plants) by humans seems to match some of the definitions of evolution I have been able to find: "a process that results in heritable changes in a population spread ...
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2answers
102 views

What are the major differences between good study habits for biology vs mathematics? [closed]

I'm a math prof. But, I've always loved reading about biology (the paleobiology of microbes and some small animals mostly) it's my hobby but I want to learn more maybe take a course. My longer term ...
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2answers
6k views

How different are these terms: Phylloclade, Phyllode, Cladophyll and Cladode?

We started with Plant Morphology in class (specifically, the morphology of angiosperms). My teacher's provided us with the following terms and their definitions. Phylloclade A modified ...
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2answers
5k views

Are 'homeothermic' and 'endothermic' synonymous?

I got this question from the comments below this answer. So, do homeothermic and poikilothermic have the same meaning as endothermic and ectothermic, respectively? A user also suggested that the ...
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1answer
54 views

What does endochorous dispersers means?

In an article (Guerrero and Tye, 2009) it talks about endochorous dispersers. Guerrero, A. M., and A. Tye. 2009. Darwin's Finches as Seed Predators and Dispersers. The Wilson Journal of Ornithology ...
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1answer
1k views

Exact definition of 'convergent' and 'divergence' in cell signalling?

From what I understand, we refer to 'signal convergence' as being when two different ligands/stimuli lead to the same (at least in part) responses inside a single cell. This may or may not be due to ...
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0answers
50 views

Majority rule definition

In this book, they talk about the majority rule. Majority rule, which retain s the edges present in more than 50% of the trees. They used that rule also in ...
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1answer
233 views

Can an exotic species be also endemic?

While talking about the evolution and conservation of dingoes in Australia, someone asked an interesting question: Can I define the dingo as an endemic species? That question, despite apparently ...
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2answers
499 views

What is the philosophical definition of life? [closed]

How does philosophy define life? And how does it overlap and contrast with the concepts and nuances of other sciences such as biology, chemistry, physics and mathematics?
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3answers
6k views

What is a gene transcript, how is it different from an allele?

Within human genetics, My current understanding of a transcript for a particular gene is that it's the exact nucleotide sequence and position of a particular instance of said gene in some individual. ...
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1answer
322 views

Problem with an analogy (Cell Membrane)

I'm studying biology for the first time seriously. I've been reading OpenStax College's material. In the section of "The Cell Membrane", I have the following problem: Choose the answer that best ...
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1answer
395 views

What is “Peripheral Dogma”?

The book, Introduction to Bioinformatics, by Arthur M. Lesk, 3rd edition; Oxford; low-price-edition; in its chapter-1 (introduction), page-no. 6 ; provided a paragraph, entitled "Dogmas: Central and ...
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1answer
720 views

The meaning of the $\alpha$ helix and $\beta$ sheets in proteins [duplicate]

I asked this question to my Biology teacher and he, in collaboration with a Chemistry teacher, couldn't find the answer. My question is the following: "What does the $\alpha$ and $\beta$ represent in ...
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154 views

Are viruses technically organisms, or not? [duplicate]

Are viruses technically organisms or not? A quick Google search query for the term; are viruses organisms?, reveals various conflicting and somewhat inconclusive ...
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1answer
953 views

What are the characteristics of a living organism? [closed]

It seemed fairly basic at first, and yet I have to ask because even a quick Google search reveals that it doesn't seem to be quite so straight-forward anymore. After more research, I found multiple ...
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2answers
311 views

Is there a formal definition of `nature` in Biology?

I've been discussing with a friend about Earth Day and at a certain point came out the question What do you call "nature"? He said that he considers "nature" basically all matter, including ...
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1answer
314 views

Was Darwin aware of the difficulties behind the concept of species?

Introduction The concept of species is a very old concept that suffers from not being a natural category. There exists no single definition that would categorize living beings into groups and that ...
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1answer
3k views

What does pseudo-irreversible mean?

In this publication (PDF) I encountered the following word: Binding of rupatadine to histamine H1 receptors isolated from the guinea-pig cerebellum and lung was demonstrated by inhibition of 3H-...
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3answers
1k views

What is the definition of a mutation?

There are two alleles that determine the sensitivity of a person to Coumadin (a medicine for blood thinners used to treat a stroke etc). Sometimes you encounter the terminology that one has a mutation ...
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1answer
345 views

What would be “Sternum-Intermediate” distance?

I've asked this question on the English Language & Usage board, not being entirely sure whether this question is strictly medical, or just English knowledge suffices to answer. Do note I am no ...
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1answer
3k views

What is a tardigrade “in tun form”?

While reading this article about tardigrades that had been previously frozen, I came across some verbiage I wasn't sure of and couldn't find any real explanation given the context. The article kept ...
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2answers
259 views

What is the definition for vitamins?

I have found the following definition on Wikipedia: An organic chemical compound (or related set of compounds) is called a vitamin when the organism cannot synthesize the compound in sufficient ...
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0answers
58 views

“Signal Advance”: Unsure of meaning or contextual use

I am reading through Recombinant DNA; Genes and Genomes - A Short Course - Third Edition by James D. Watson, et. al. and I came across this paragraph in the discussion about discrete factors of ...
3
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1answer
311 views

How do we call a region of low carrying capacity?

I am looking for a convenient word to define a region of the landscape where the local carrying capacity (population size) for a given species is low but different from zero. The species is still ...
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1answer
2k views

Definitions of common and rare disease

Is there an epidimiological way to define rare and common diseases ?
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1answer
328 views

Can a relationship exist that is mutualistic/parasitic/etc. but not considered symbiotic?

Wikipedia definition of symbiosis: "Symbiosis (from Greek σύν "together" and βίωσις "living")[2] is close and often long-term interaction between two or more different biological species." Wikipedia ...
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2answers
23k views

Is blood regarded as an organ?

It consist approximately 7 percent of body weight. By definition organ is composed of multiple tissues. Blood is a fluid, a circulating tissue. Therefore can we call this fluid system a liquid organ?...
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2answers
810 views

What is Environmental Robustness? Is it different from plasticity?

Hansen (2006) in his review uses the concept of environmental robustness independently of the other concepts of robustness (at pages 139 and 140) without defining ...
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2answers
404 views

Definitions of robustness and canalization

The concepts of robustness and canalization are fashionable today in the biology literature. However, I am not sure of their definitions and I am not sure either that all authors actually use the same ...
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1answer
852 views

What does “Mutational Variance” mean?

Background The concept of mutational variance can be found in many articles including this one for example. The mutational variance of a trait number $i$ can be found in the M-matrix in position $m_{...
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1answer
3k views

Soft and Hard selection

Seems to me that these two sources (M. Whitlock, B. Wallace) use different definitions of soft and hard selection. M. Whitlock: Soft selection occurs when the relative fitness of an individual is ...
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1answer
14k views

What is the definition of a stringent/relaxed plasmid?

I have found a publication which proposes some definitions, including a definition for strict and relaxed replication. The definitions are: Relaxed control of plasmid replication. Relaxed control ...