Q: Zygotic meiosis is a characteristic of:

A. Correct option A B. Explanation for correct option:When the zygote divides meiotically or when zygote undergoes reduction division after division of nucleus i.e. after karyogamy it is called as zygotic meiosis. Zygote is a stage that is formed after fertilization.Chlamydomonas is haploid plant. Hence, zygotic meiosis occurs in chlamydomonas.

Question 1

Strobili or cones are found in:

Accepted Answer

Strobili or cones are the dense and compact structures present on non-flowering plants. They contain sporangia and perform function of protecting spores from wild animals and harsh conditions of environment.In Equisetum, the strobili are present at the terminal position on stem. Equisetum are also known as horsetails and come under the category of ferns.Thus, the correct answer is (C).

Question 2

Which of the following pairs is of unicellular algae?

Accepted Answer

Chlorella and Spirulina are unicellular algae. Gelidium, Gracilaria, Laminaria and Sargassum are multicellular. But, Volvox is colonial.Thus, the correct answer is (C).

Question 3

From the evolutionary point of view, retention of the female gametophyte with developing young embryo on the parent sporophyte for some time, is first observed in _______________.

Accepted Answer

In Pteridophytes, megaspore is retained for some times in female gametophyte. However, the permanent retention is required for seed formation and hence seed is not formed.That's why Pteridophytes are said to be precursors of seed habit.So, the correct answer is 'Pteridophytes'

Question 4

Which one is wrongly matched?

Accepted Answer

(a) Gemma cups are the green, multicellular, asexual bud present in the thallus helps in asexual reproduction in Marchantia. (b) Polysiphonia is a red algae. They do not possess uniflagellate gametes and sexually reproduces by non-motile gametes.(c) Chlorella is the unicellular algae and belongs to Chlorophyceae. (d) Biflagellate zoospores are the pear-shaped structure with two unequal laterally attached flagella. It helps in asexual reproduction in brown algae. Thus, the correct answer is option B.

Question 5

An example of colonial alga is:

Accepted Answer

Volvox is a unicellular green alga found in freshwater bodies. It is photosynthetic in nature. It forms colonies of around 50,000 cells which are spherical in shape. Thus the correct answer is option C.

Question 6

Life cycle of Ectocarpus and Fucus respectively are:

Accepted Answer

Answer: (D) Haplodiplontic, Diplontic.Explanation:Haplodiplontic cycle is the life cycle that is intermediate between haplontic and diplontic. In this, both the haplontic and diplontic are free-living and multicellular. In diplontic life cycle, the diploid sporophyte is dominant. Ectocarpus and Fucus are algae that have both haplodiplontic and diplontic life cycles.

Question 7

Functional megaspore in an angiosperm develops into:

Accepted Answer

In angiosperms or flowering plants, the megaspore mother cell produces a functional megaspore that develops into an embryo sac through two distinct processes megasporogenesis (formation of the megaspore in the nucellus, or megasporangium), and megasporogenesis (development of the megaspore into the embryo sac, or megagametophyte). Thus, option D is the correct answer.

Question 8

Zygotic meiosis is a characteristic of:

Accepted Answer

A. Correct option A&#10;&#10;B. Explanation for correct option:When the zygote divides meiotically or when&#10;zygote undergoes reduction division after division of nucleus i.e. after&#10;karyogamy it is called as zygotic meiosis. Zygote is a stage that is formed&#10;after fertilization.Chlamydomonas is haploid plant. Hence, zygotic meiosis occurs in chlamydomonas.

Question 9

Which one of the following statements is wrong?

Accepted Answer

(A) Correct option (D)(B) Explanation of correct answer:Agar-agar is a gelling agent with unbranched polysaccharides and is used in microbiology as a solidifying agent of liquid culture mediums. It is extracted from the cell wall of red algae, mostly from Gelidium species and Gracilaria species.Laminaria and Sargassum are the brown algae and are cultivated as a crop. Algae are green photosynthetic organisms that release oxygen in immediate vicinity through the process of photosynthesis. The cell wall of brown algae has an inner cellulose layer and outer gelatinous coat which is composed mainly of algin, it is used as an emulsifying agent and a stabilizer.

Plant Kingdom