>
>
Time management is very much important in IIT JAM. The eduncle test series for IIT JAM Mathematical Statistics helped me a lot in this portion. I am very thankful to the test series I bought from eduncle.
Nilanjan Bhowmick AIR 3, CSIR NET (Earth Science)
Gurmeet Singh posted an Question
August 20, 2020 • 17:17 pm
![]()
30 points
30 points
- IIT JAM
- Geology (GG)
Please explain meaning of last line,. from "occasionally,......by shell collector"
of calcium.caroonare pecipiiateu iu nature of coiled shells, gastropods possess a quality known as chirality or "handedness." Over_ 90% of gastropods have a dextral or "righthand shell. Left-hand coiled shells are referred to as sinistral. If the opening (aperture) of a shell is on the right side when the shell is held with spire pointing upwards, the shell is said to be dextral. Occasionally, dextral species will produce sinistral shells, and vice-versa. These oddities are highly sought after by shell collectors. cnGcies of arboreal (treedwelling) land snails that show normally mixed coiling.
2 Answer(s)
Answer Now
- 0 Likes
- 2 Comments
- 0 Shares
-
![comment-profile-img]()
>
-
![comment-profile-img]()
>
Sajan sarthak
![best-answer]()
I would rather suggest a book . This material is using unusual words and not easy to understand. please study book for more clear . i am even not able to understand this language.
![eduncle-logo-app]()
then sir, i ll not b able to achieve my target - each unit per week......how much deepness required for paleontology topics. sir.
![eduncle-logo-app]()
1 week enough for paleontology total
![eduncle-logo-app]()
1week and 2 hours daily
![eduncle-logo-app]()
ok sir.
Do You Want Better RANK in Your Exam?
Start Your Preparations with Eduncle’s FREE Study Material
- Updated Syllabus, Paper Pattern & Full Exam Details
- Sample Theory of Most Important Topic
- Model Test Paper with Detailed Solutions
- Last 5 Years Question Papers & Answers
Sign Up to Download FREE Study Material Worth Rs. 500/-
Rahul kumar Best Answer
Shell coiling is unique for different species and they are found as uniquely coiled either dextral or sinistral in general. However there are some exceptions which are mentioned in the last line. The last line means that sometimes it was seen that the species which are dextral in general can form sinistrally coiled shells and species which are sinistral in general form dextral coiled shells. This was mainly reported by persons who collect the shells from different places. The exceptional shell cooling may indicate very different genetic conditions or the environment in which they thrived.
sir why it happens? and how it happens.
The reason behind this is not yet known but there might be some genetic or environmental factors causing such changes.
sir how much deep i should go with such paleontology topic - mollusc(bivalvia, cephalopods, gastropod etc.) , trilobite, graptolites, anthozoa, echinodermata, brachiopods.
For JAM, I would suggest you to have command on morphology, environment, geological evolution and detailed information about important genus. It should be sufficient for JAM.