Question

Which of the following is found in Ulva but not in lower plants?
A. Alternation of generation
B. Generations look alike
C. Sperms and eggs are produced
D. Both B and C

Answer 1

Ulva is a green algae which is also called sea lettuce. It shows a complex life cycle consisting of haploid gametophyte and the diploid sporophyte. Both of these are multicellular structures.

Step by step answer: Ulva is a green alga which is used as food. They are called green algae because of the presence of chlorophyll a and b. They prepare food by photosynthesis and it is stored as starch and proteins. It contains a cell wall that is made up of cellulose and pectose. The reproduction in Ulva is mainly by fragmentation. It also reproduces by producing zoospores. Like other kinds of green algae, Ulva also has a complex life cycle. It consists of both gametophyte and sporophyte. The gametophyte is haploid whereas sporophyte is diploid in nature. Both of them are similar to each other. Because of this reason, the life cycle in Ulva is called isomorphic and biphasic. Isomorphic is because both gametophyte and sporophyte look similar to each other and biphasic as it contains both of them. Sporophytes produce haploid spores by meiosis and haploid gametophytes are formed from them. Zoospores contain flagella and are motile in nature.
Hence the correct option is B.

Note: Life cycle of Ectocarpus is also called isomorphic because sporophytes and gametophytes are similar in it. It is brown algae and lives in seawater. It is an example of haplo-diplontic algae. It differs from other types as most algae are haplontic. Fucus is an alga that is diplontic in nature.