STD 12 - 8. microbes in human welfare — NEET STD 11 Science — Question

Coca alkaloid or cocaine is obtained from

Which of the following characters for connective tissues are correct ?
(i) It is most abundant and widely distributed in the body of complex animals.
(ii) It includes cartilage, bone, adipose and blood.
(iii) Cells of blood, secrete fibres of structural proteins called collagen or elastin.
(iv) Matrix made up of modified polysaccharides.
(v) Areolar tissue present beneath the skin and it is a dense connective tissue.
(vi) Loose connective tissue contains fibroblasts, macrophages and mast cells.
(vii) Fibroblasts produce and secrete fibres.

Assertion : Interferons are a type of'antibodies produced by body cells infected by bacteria.

Reason : Interferons stimulate inflammation at the site of injury.

Prothrombin is

Which one is odd pair

Alleles are form of

Read the following statements.
(i) Annelids possess longitudinal and circular muscles which helps in osmoregulation.
(ii) Nereis possess lateral appendages, parapodia that help in swimming.
(iii) Nephridia helps in osmoregulation and excretion in annelids.
(iv) Neural system of annelids consists of paired ganglia connected by lateral nerves to a single ventral nerve cord.
(v) Arthropods is the largest phylum of Animalia and over 2/3rd of all named species on earth are member of this phylum.
(vi) The body of arthropods is covered by chitinous exoskeleton.
(vii) Statocysts are present as balance organs in arthropods.
(viii) Excretion takes place in arthropods through malpighian tubules.
(ix) Fertilisation is external in arthropods.
(x) In phylum arthropod, locusta member is gregarious pest and limulus is a living fossil.
(xi) Mollusca is the second largest animal phylum. The body of member of this phylum is covered by calcareous shell.
(xii) In mollusca, a soft and spongy layer of skin forms mantle over the visceral hump. The space between hump and the mantle is called mantle cavity.
(xiii) The mouth contains a file-like rasping organ for feeding, called radula in echinodermata.
(xiv) Pinctada is commonly known as pearl oyster and pila as apple snail.
(xv) Sepia is commonly known as cuttlefish and octopus as devil fish.
(xvi) Digestive system is complete in echinodermata with mouth on the dorsal side and anus on ventral side of body.
(xvii)The most distinctive feature of sponges is the presence of water vascular system.
choose the option with all correct statements :-

Main source of amoebic dysentery is