Questions looking for clarifications or definitions of biological terminology.

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10
votes
3answers
13k views

Do apes and humans share 99% of DNA or 99% of genes? What is the difference?

I made an answer on the Scifi.SE that can be read here. It is about how the characters in the story Jurassic Park might have gotten DNA for all the species shown. In my answer, I said this: Apes ...
8
votes
2answers
2k views

Is blood an organ according to biology?

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 ...
7
votes
1answer
71 views

Can an organism obtaining a part of its genome via horizontal gene transfer be called a “hybrid”?

Wikipedia definition of "hybrid" offers many competing definitions. But most seem to be centered on sexual-reproduction gene transfer. Is there an official (in a textbook or widely accepted peer ...
6
votes
2answers
184 views

Transitivity of Species Definitions

There are many definitions of "species" which usually take the form Two individuals are of the same species if ... An implied (rarely made explicit) property of any sensible species definition ...
6
votes
1answer
173 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 ...
5
votes
1answer
2k 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 ...
5
votes
2answers
99 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 ...
4
votes
3answers
1k views

Polymorphism in cnidarians?

To me, the phenomenon of polymorphism in cnidarians is particularly troubling. I gather that it essentially refers to existence of various different forms or kinds of individuals, i.e. zooids and ...
4
votes
1answer
95 views

How would one describe the R-factor in crystallography?

Yes, there is the wikipedia definition, but how would one explain this concept to a non structural biologist?
3
votes
1answer
1k views

Are spiders part of the study of entomology?

The definition of entomology says it is the science of studying insects. I know spiders are not insects but does entomology include studying spiders as well? Otherwise is there any name to the ...
3
votes
1answer
5k views

What is a suicide plasmid?

What is a suicide plasmid? Example: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2737453/ mentions a "suicide vector". See also ...
3
votes
1answer
2k views

What is the definition of “dry weight” and “dry cell weight”?

As I understand it, the dry weight of something is its weight minus the weight of its water content. Is this the definition? What about dry cell weight?
3
votes
1answer
485 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 ...
3
votes
2answers
909 views

What is an organism?

The definition of an organism Wikipedia gives is An organism is any contiguous living system. I understand that these are not organisms according to this definition: A bird and a tree it's ...
2
votes
2answers
90 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 ...
2
votes
2answers
1k views

What is a cortical circuit?

I have read about cortical circuits in the context of connectomics (e.g. any example here) and computational neuroscience (e.g. any example here), but a simple Google/Wikipedia does search not show an ...
2
votes
1answer
203 views

Limb polarity such as writing handedness, golf handedness and natural football foot

Define the term "limb polarity" to mean things such as writing handedness, golf handedness, throwing ball arm preference and natural boxing hand. I avoid using the term "handedness" because of its ...
2
votes
1answer
104 views

Definition of Sexual Selection?

How do you define Sexual Selection (SS)? (One might want to subdivide SS into intra- and inter- SS to answer) Is SS clearly different from Natural Selection (NS)? Is SS nested within NS or are NS ...
1
vote
1answer
29 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 ...
1
vote
1answer
37 views

Definitions of common and rare disease

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

What is an on-line measurement? What is an off-line measurement?

See it used here: http://en.wikipedia.org/wiki/Fed-batch. In the table giving the different strategies to control growth in a fed-batch culture, one finds, for example: "on-line measurement of ...
1
vote
1answer
54 views

What is a sex-biased gene?

How do you define a male-biased gene and a female-biased gene as they are found in the abstract of this article.
1
vote
1answer
51 views

What does “developmentally programmed” mean?

What does the term "developmentally programmed" mean? I can't seem to find a definition anywhere. What would the alternative (i.e. not developmentally programmed) imply?
1
vote
1answer
565 views

What is the difference between abiogenesis and spontaneous generation?

As we all should know, abiogenesis and spontaneous generation are far from identical. For one, spontaneous generation was disproven with Pasteur, and abiogenesis seems to be a solid scientific theory. ...
1
vote
0answers
181 views

On the definition of gDCW (gram dry cell weight)

I need some clarification on the concept of gram dry cell weight. The unit acronym gDCW stands for gram dry cell weight. My interpretation is that 1 gDCW is equivalent to 1 gram of dry cells, but I ...
0
votes
1answer
29 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 ...
0
votes
1answer
335 views

What the difference between an inverted and everted retina?

I'm looking specifically for examples and comparisons, because the definitions of inverted and everted are remarkably similar; e.g. from Dictionary.com/Reference.com: everted verb (used with ...