- AAlfred Wallace
- ✓Ernst Heckel
- CKarl Ernst vol Baer
- DCharles Darwin
Alfred Wallace, a naturalist who worked in Malay Archipelago had concluded that natural selection act as mechanism of evolution.
Karl Ernst von Baer disapproved the proposal given by Ernst Hackel and proposed that embryos never pass through the adult stages of other animals.
Charles Darwin proposed natural selection as mechanism of evolution.
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Reason : Proteins which can be synthesized only by genetic engineering are effective against viruses.
($i$) It consists of a network of trachea, that open through $12$ pairs of small holes called spiracles present on the lateral side of the body.
($ii$) Thin branching tubes carry oxygen from the air to all the parts.
($iii$) The opening of the spiracles is regulated by sphincters.
($iv$) Exchange of gases take place at the tracheoles by diffusion.