How do Organisms Reproduce? — Science STD 10 — Question

What criteria can be used to decide whether something is alive?

An element has its electron configuration as 2, 8, 2. Now answer the following question.
With which of the following elements would this element resemble?
(Atomic numbers are given in the brackets)
N(7), Be(4), Ar(18), Cl(17)

Vinegar is a 12-15 % aqueous solution of acetic acid.

If you want to see an enlarged image of your face, state whether you will use a concave mirror or a convex mirror?

Which fossil fuel is conserved.
when we save on electricity?

Characters of a phylum are given below. Read them carefully and answer the questions:
(a) Spines of calcium carbonate are present on the body, (b) These animals are exclusively marine, (c) They perform the locomotion with the help of tube feet, (d) Their skeleton is made up of calcareous plates or spicules.
(i) Animals of which phylum show the above character?
(ii) Give an example from that phylum.
(iii) These animals can be classified with the help of which criteria of new system of animals classification.

What type of bonds are present in the following molecules? Draw their electron-dot structures.

The number of malaria patients in a village increased tremendously when large number of frogs were exported from the village. What could be the cause for it?

complete the statements by choosing correct options from bracket.
(Genes, Mutation, Translocation, Transcription, Gradual development, Appendix)
Evolution means ………….

Name two parts of the eye which refract light rays (or bend light rays).