Male and female gametophytes do not have an
independent free living existence in:
Explanation:
In angiosperms, the male and female gametophytes are microscopic and develop inside the sporophyte tissues (anther and ovule) and are dependent on the sporophyte for nutrition and development. Hence, they do not have an independent free-living existence.
🧠Did You Know?
The pollen grain (male gametophyte) and the embryo sac (female gametophyte) are produced inside the parent plant, not free in the environment.
💡 NCERT Memory Line:
In angiosperms, the gametophytic phase is reduced and dependent on the sporophyte.
Which of the following pairs is of unicellular
algae?
Explanation:
Chlorella and Spirulina are considered unicellular organisms in NCERT. Chlorella is a simple, single-celled green alga. Spirulina is described as a blue-green alga (cyanobacterium) and, for the purposes of NCERT multiple-choice questions, treated as unicellular. Thus, this pair represents unicellular algae.
? Did You Know?
Other options include multicellular forms: Laminaria and Sargassum (brown algae), Gelidium and Gracilaria (red algae), and Anabaena (cyanobacterium) with Volvox (colonial green alga), not unicellular.
? NCERT Memory Line:
Unicellular green algae like Chlorella, and unicellular blue-green algae (spirulina) are examples used to illustrate single-celled photosynthetic organisms in NCERT discussions.
