STD 12 - 6. evolution — NEET STD 11 Science — Question

Mechanisms of breathing vary among different groups of animals depending mainly on their habitats and levels of organisation, which option contain all correct statements ?
(i) Lower invertebrates like sponges, coelenterates, flatworms, etc., exchange O₂ with CO₂ by simple diffusion over their entire body surface.
(ii) Earthworms use their moist cuticle for exchange O₂ with CO₂.
(iii) Insects have tracheal tubes to transport atmospheric air within the body.
(iv) Special vascularised structures called gills are used by most of the aquatic arthropods and molluscs.
(v) Terrestrial forms use vascularised bags called lungs for the exchange of gases.
(vi) Among vertebrates, fishes use gills whereas reptiles, birds and mammals respire through lungs and also use skin for respiration.

AlDS from India was reported in

Poikilothermous animals having single occipital condyle will belong to

The acromion process articulates with the

Given below are two statements:
Statement I: In prokaryotes, the positively charged DNA is held with some negatively charged proteins in a region called nucleoid.
Statement II: In eukaryotes, the negatively charged DNA is wrapped around the positively charged histone octamer to form nucleolus.
Choose the correct answer from the options given below:

Geological evidence for most primitive mammal is found in

Assertion: Seminiferous tubule is a structural and functional unit of testis.
Reason: Each testis has about 250 compartments called testicular lobules and each lobule contains one to three highly coiled seminiferous tubules and it form sperms.

A complete digestive system has