Solution

Balbiani rings (after the name of its discoverer, Balbiani) are exceptionally large puffs on the polytene chromosomes. They are sites with a very high RNA production. 

These puffs are particularly well suited for studies of the structure of active genes and the synthesis and transport of specific RNA-protein (RNP) particles.

Solution

In gymnosperms, ovules are not enclosed by ovary wall. Seeds do not occur inside a fruit. They are naked.

Horsetail is the common name of Equisetum.

Pteridophyte s like Selaginella and Salvinia are heterosporous and possess two types of spores, i.e. microspores and megaspores.

Cycas has an unbranched columnar stem while Cedrus possess branched stem.

A monoploid cell is a cell with half the normal number of chromosomes, these are gametes.

Fusing two of these together restores the normal number of chromosomes in fertilization.

A cotyledon is part of a seed and a polyploid cell is a cell with more than the normal number of chromosomes.

We all possess 2 genes for every trait that are located on homologous chromosomes. A homozygous genotype means that an individual has the same genes for a particular trait on the homologous chromosomes. We represent genes as letters and for any one trait we must use the same letter, a capital letter meaning the dominant gene while a lower case letter meaning a recessive gene.

SOLUTION

Frogs breathe via positive pressure because they have no diaphragm. Since they have no diaphragm, they need to force air into their lungs by decreasing the size of their oral cavity and closing off their external nares. If their mouth is open for some time, it may die as it will not be able to breathe.