Biology Test 141

In evolutionary biology, convergent evolution is the process whereby organisms not closely related (not monophyletic), independently evolve similar traits as a result of having to adapt to similar environments or ecological niches. It is common to whale, seal and shark.
Hence, the correct option is (D).

The peritoneum is the serous membrane forming the lining of the abdominal cavity or coelom in amniotes and some invertebrates, such as annelids. It covers most of the intra-abdominal (or coelomic) organs and is composed of a layer of mesothelium supported by a thin layer of connective tissue.
Hence, the correct option is (B).

In the third week, the primordial germ cells wander - in an amoeboid manner - from the primary ectoderm into the yolk sac wall and collect near the exit of the allantois. The primordial germ cells are now extraembryonal, lying in the endoderm and mesoderm of the yolk sac wall.

Hence, the correct option is (A).

Whittaker proposed an elaborate five-kingdom classification – Monera, Protista, Fungi, Plantae and Animalia. The main criteria of the five-kingdom classification were cell structure, body organization, mode of nutrition and reproduction, and phylogenetic relationships.
Hence, the correct option is (B).

A wildlife sanctuary is a naturally occurring sanctuary, such as an island, that provides protection for wildlife species from hunting, predation, competition or poaching.

The wildlife sanctuaries are established to protect the endangered species.

It is quite difficult to always relocate the animals from their natural habitat, therefore, protecting them in their natural environment is advantageous.

The endangered species are specially monitored in the wildlife sanctuaries. If they reproduce and grow in number while under protection, few specimens can be kept for breeding in the conservation parks for their survival.

Biologist activities and researches are permitted in the wildlife sanctuaries so that they can learn about the animals living there.

A few sanctuaries take in injured and abandoned animals and rehabilitate them to health before releasing them in the forest.

Wildlife sanctuaries preserve the endangered species and protect them from humans and predators.
Hence, the correct option is (D).

Inside cilia and flagella is a microtubule-based cytoskeleton called the axoneme. The axoneme of primary cilia typically has a ring of nine outer microtubule doublets (called a 9+0 axoneme), and the axoneme of a motile cilium has two central microtubules in addition to the nine outer doublets (called a 9+2 axoneme). The axonemal cytoskeleton acts as a scaffolding for various protein complexes and provides binding sites for molecular motor proteins such as kinesin-2, that help carry proteins up and down the microtubules.
Hence, the correct option is (C).

Physiologically dry soil means that water is present in the soil but is not available to the plants either because of high salt concentration, or lack of water in liquid form or poor aeration. These conditions respectively occur in saline marshes, cold deserts and waterlogged soil.
Hence, the correct option is (A).

Pellagra is a disease characterised by diarrhoea, dermatitis and dementia. If left untreated, death is the usual outcome. It occurs as a result of niacin (vitamin B-3) deficiency. Niacin is required for most cellular processes.
Hence, the correct option is (D).

The synaptonemal complex is a large proteinaceous structure that holds together homologous chromosomes during Meiosis, providing the structural framework for meiotic recombination and crossover formation. It is an evolutionarily-conserved protein assembly that forms between homologous chromosomes. The synaptonemal complex begins to form during the zygotene phase of Prophase I in the first division in Meiosis and is complete in the pachytene phase. Acting like a 'zipper' it holds the homologous chromosomes together, aligning them perfectly. After complete synapsis, crossing over occurs and in the diplotene phase, where the chiasma is visible, the synaptonemal complex 'unzips' and disappears.

Hence, the correct option is (A).

Until very recently zinc deficiency of the rice plant had not been shown to occur in the field. Y. L. NENE was the first to show that a foliar application of zinc sulfate corrects a disorder of the rice plant long known as Khaira disease in North-Central India.
Hence, the correct option is (B).