Tag: biology

Motile sperms are absent in Rhizopus. In Rhizopus, gametangial copulation takes place. The terminal part of sub aerial hyphae acts as coenogametes which fuse to form a diploid zygote and then a resting spore called as zygospore. It contains several diploid nuclei with reserve material. It undergoes meiosis to form spores which on germination give rise to new mycelium.

Correct match of algal class and its characteristic flagellation: 

Green beetles living in green bushes are camouflaged by their surroundings and are hence not eaten by the crows. This is a defense strategy employed by the beetles in order to escape predation. In the F1 generation crossing homozygous dominant (pure tall) and homozygous recessive (pure dwarf) plants will result in the heterozygous condition (Tt) with a phenotype of all tall plants as they will still have the dominant genotype. Removal of tails cannot be passed on from one generation to another, as it is not a heritable change and not a part of the genetic makeup of the organism. The isolation of an organism by a geographical barrier such as a river is called allopatry and hence governs the speciation of a sub-population such as blue beetles from green beetles. When a  migrant beetle reproduces with the local population the genes of migrant beetle enter the new population by the means of gene flow (also known as gene migration or allele flow) is the transfer of genetic variation from one population to another.  

Primary producers in a terrestrial ecosystem live in and around the organic matter. Since they are not mobile, they live and grow where there are nutrients to sustain them. The primary producers include green plants, lichens, moss, bacteria, and algae. 

Spirogyra is a freshwater green alga. During its sexual cycle, the zygospore is formed which is considered as the only diploid phase in its life cycle. In favourable conditions, When zygospore burts and it is one haploid nucleus form germ tube.

The correct answer is C.