Plant Kingdom Test - 68

• The free-living, multicellular and photosynthetic gametophytes of pteridophytes are called as the prothallus. 
• Pteridophytes show alternation of generations. The dominant sporophyte produces spores through meiosis. The gametophyte generation forms gametes by mitosis. The spores are produced by the sporangia in the spore mother cells. These spores germinate and give rise to gametophytes. 
• The gametophytes (prothallus) produces the male sex organs called antheridia and female sex organs called archegonia.
• So the correct option is B.
  

Phenetics is a system of classification based on similarity between organisms without regard- to their evolutionary relationships. In this type of classification the organisms are arranged according to over ail similarity of existing organisms based on observable characters.

• Dictyota is seaweed of class Phaeophyceae. They are marine and having laminarin, mannitol as their reserve foods. They have pigments like chlorophyll a, c, fucoxanthin.
• Polysiphonia is a red algae, it is usually well branched and they are attached to rocky surface or base with the help of rhizoids.
• So,the correct answer is " Dictyota, Polysiphonia ".

Red algae are defined as eukaryotic algae which possess chlorophyll a, phycobilins, floridean starch as food reserve, abundant phycocolloids (like agar, carrageenin, and funori) but lack flagellate cells. Sexual reproduction is oogamous. The male sex organ is called spermatangium or antheridium. It produces non-flagellate male gamete known as spermatium. The female sex organ is flask-shaped and is termed carpogonium. Carpogonium possesses an elongated receptive organ named trichogyne. Spermatia are carried by water currents to trichogyne tips for effecting fertilization. The female sex organ remains attached to the plant and forms a new structure called carposporophyte.

In the given figure, we can observe that there are two flagella; one lies longitudinally and the other transversely in a furrow between the wall plates. So this is the characteristics feature of Dinoflagellates.

Correct Option: C

Explanation: 

• Numerical taxonomy is easily carried out using computers based on all observable characteristics, numbers, and codes are assigned to all the characters, and the data are then processed.

• Each character is given equal importance.

•  simultaneously hundreds of characters can be considered cytotaxonomy that is based on cytological information like chromosome number, structure, behavior.

• In  Chemotaxonomy, we use the chemical constituents of the plant to resolve confusion, is also used by taxonomists these days.

Hence, the incorrect pair is chemotaxonomy - chromosome number and structure.

Algae are mostly haploid. They show haplontic lifestyle i.e. for the most part of the life haploid is the dominant stage. Fusion of gametes results in diploid sporophyte in algae which undergoes meiosis to form haploid gametophyte. There are no free-living sporophytes. The gametophyte is the dominant phase.

The spores in pteridophytes germinate to give rise to inconspicuous, small but multicellular, free-living, mostly photosynthetic thalloid gametophytes called prothallus.

Correct Answer: B

Explanation:

• Phaeophyta, also known as brown alga is a marine alga constituted of chlorophyll including brown pigments.
• It is present in diverse forms in nature and is often of gigantic size.
• The main body i.e. thallus of this alga is composed of three sections including holdfast, blade, and stipe. The blade or fronds are responsible for the process of photosynthesis.
• Some species may have an air bladder supporting their floatation on the water surface.

Hence, the correct option is (A) – Frond, (B) – Stipe, (C) - Holdfast