Dictionary » S » Sickle

Sickle

sickle

1. A reaping instrument consisting of a steel blade curved into the form of a hook, and having a handle fitted on a tang. The sickle has one side of the blade notched, so as always to sharpen with a serrated edge. Cf. Reaping hook, under reap. When corn has once felt the sickle, it has no more benefit from the sunshine. (Shak)

2. (Science: astronomy) A group of stars in the constellation leo.

(Science: botany) Sickle pod, a kind of rock cress (Arabis Canadensis) having very long curved pods.

Origin: OE. Sikel, AS. Sicol; akin to D. Sikkel, G. Sichel, OHG. Sihhila, Dan. Segel, segl, L. Secula, fr. Secare to cut; or perhaps from L. Secula. See Saw a cutting instrument.


Please contribute to this project, if you have more information about this term feel free to edit this page



Results from our forum


Re: Beneficial mutations vs harmful

... percent are beneficial. Of these beneficial mutations, many are actually destructive, they just happen to help in that particular environment (eg. sickle cell anemia). Neutral mutations may or may not be proliferated as they have no beneficial or disadvantageous aspect. In the face of so much destruction, ...

See entire post
by Coelacanth
Sun Oct 13, 2013 6:08 am
 
Forum: Evolution
Topic: Beneficial mutations vs harmful
Replies: 12
Views: 7456

Beneficial mutations vs harmful

... outweigh their negative consequences. Perhaps such mutations could be called "temporarily beneficial" . For example, maybe the sickle cell allele, which is more common where malaria is rampant, will be weeded out once malaria is no longer a threat to that population. i.e. it's ...

See entire post
by wildfunguy
Wed Oct 09, 2013 3:30 pm
 
Forum: Evolution
Topic: Beneficial mutations vs harmful
Replies: 12
Views: 7456

Beneficial mutations vs harmful

... failed to spread to areas where this was not a case. So like you said, many "beneficial" mutations can be harmful as well - be it the sickle cell gene or the ability to produce lactase - it all depends on the environment of the given organism. Sickle cell aenemia and lactase production ...

See entire post
by biohazard
Tue Oct 08, 2013 12:39 pm
 
Forum: Evolution
Topic: Beneficial mutations vs harmful
Replies: 12
Views: 7456

Beneficial mutations vs harmful

... percent are beneficial. Of these beneficial mutations, many are actually destructive, they just happen to help in that particular environment (eg. sickle cell anemia). My question : In the face of so much destruction, how can occasional beneficial/constructive mutations add up evolution? My Conclusion ...

See entire post
by Doom
Mon Oct 07, 2013 6:20 am
 
Forum: Evolution
Topic: Beneficial mutations vs harmful
Replies: 12
Views: 7456

Re: Genetics Homeworkkk!!! PLEASE HELP

... one more problem: If parents are heterozygous and they have five children, what is the possibility of having the first and the fifth child with sickle-cell anemia?

See entire post
by runaway
Mon Nov 05, 2012 9:17 pm
 
Forum: Genetics
Topic: Genetics Homeworkkk!!! PLEASE HELP
Replies: 5
Views: 3844
View all matching forum results

This page was last modified 21:16, 3 October 2005. This page has been accessed 1,746 times. 
What links here | Related changes | Permanent link