Transport in Plants — BIOLOGY STD 11 Science — Question

Enzymes are proteins. Proteins are long chains of aminoacids linked to each other by peptide bonds. Aminoacids have many functional groups in their structure. These functional groups are, many of them at least, ionisable. As they are weak acids and bases in chemical nature, this ionization is influenced by pH of the solution. For many enzymes, activity is influenced by surrounding pH. This is depicted in the curve below, explain briefly.

Write four differences between the animals of Platyhelminthes and those of Aschelminthes. Give an example of each.

1. Draw a labelled diagram of the basic body plan of chordates.
2. Mention the four characteristic features which all chordates possess.

There is a myth that immediately after heavy rains in forest, mushrooms appear in large number and make a very large ring or circle, which may be several metres in diameter. These are called as ‘Fairy rings’. Can you explain this myth of fairy rings in biological terms?

How useful is the study of the nature of body cavity and coelom in the classification of animals?

Are the different types of plastids interchangeable? If yes, give examples where they are getting converted from one type to another.

Terrestrial animals are generally either ureotelic or uricotelic, not ammonotelic, why?

Explain why.

1. Water can reach up to endodermis through apoplast but it moves through the endodermis by symplast.
2. Primary xylem in root is exarch and in stem it is endarch.

Write a short account on herbarium as a taxonomic aid.

Draw a well labelled diagram of the circulatory system of cockroach.