Morphology of Flowering Plants Test 67

Awns are characteristic of many grasses (Poaceae), where they extend from the lemmas of the florets. This often makes the hairy appearance of the grass synfloresce. Awns may be long or short, straight or curved, single or multiple per floret. Some genera are named after their awns, such as the three-awns (Aristida). In some species, the awns can contribute significantly to photosynthesis, as, for example, in barley. The awns of wild emmer wheat spikelets effectively self-cultivate by propelling themselves mechanically into soils.
During a period of increased humidity during the night, the awns of the spikelet become erect and draw together and in the process push the grain into the soil. During the daytime the humidity drops and the awns slacken back again. However, fine silica hairs on the awns act as ratchet hooks in the soil and prevent the spikelets from reversing back out again. So, awn of wheat and barley develops from lemma. 
Therefore, the correct answer is option C.

Brassica campesteris belongs to family Brassicaceae.
Flowers of family Brassicaceae shows parietal placentation.
Flowers of family Brassicaceae shows superior ovary i.e. sepals and petals are below the ovary. Such flower is called as Hypogynous.
Flowers of family Brassicaceae has unilocular ovary. 
Flowers of family Brassicaceae e.g., Brassica campesteris possess unilocular ovary which becomes bilocular due to false septum called as replum. 
Therefore, the correct answer is option A.

The Asteraceae or Compositae are an exceedingly large and widespread family of flowering plants (Angiospermae). The main feature of the family is the composite flower type in the form of capitula surrounded by involucral bracts. The name Asteraceae comes from Aster, the most prominent genus in the family, that derives from the Greek, meaning star and is connected with its inflorescence star form. As for the term Compositae, more ancient but still valid, it obviously makes reference to the fact that the family is one of the few angiosperm ones to have composite flowers. Euphorbiaceae, Fabaceae and Malvaceae family names are not based on their inflorescence. 
Therefore, the correct answer is option B.

Family Liliaceae is characterised by trimerous flowers. The flowers may be arranged (inflorescence) along the stem, developing from the base or as a single flower at the tip of the stem or as a cluster of flowers. They contain both male (androecium) and female (gynoecium) characteristics and are symmetric radially, but sometimes as a mirror image. Most flowers are large and colourful.
So, the correct answer is 'Trimerous flower'

Inflorescence is the arrangement of flower on the floral axis. There are two types of inflorescence as racemose and cymose. In racemose type, the main axis is unlimited in growth. It never terminates into a flower. There are many sub-types of racemose inflorescence. Of them, umbel inflorescence is one of the sub-type of racemose. 
Umbel inflorescence contain a very shortened and suppressed axis. It contains flowers with equal length stalks and form a cluster. It gives an umbrella like appearance. 
Musa and Colocasia possess spadix type of inflorescence. Spadix also belongs to racemose type of inflorescence. It has a spike with fleshy axis which is enclosed by one to many, large bracts. The flowers are borne inside this structure.
Helianthus possess head or capitulum type of inflorescence. Head or capitulum also belongs to racemose type of inflorescence. It possess a flattened, convex main axis called receptacle. This receptacle bears flowers in centripetal order. The whole inflorescence is surrounded by a whorl of bracts. 
Coriandrum shows umbel inflorescence with  a very shortened and suppressed axis. It contains flowers with equal length stalks and form a cluster. It gives an umbrella like appearance. 
Therefore, the correct answer is option C.

Cauliflower is one of several vegetables in the species Brassica oleracea, in the family Brassicaceae. It is an annual plant that reproduces by seed. Typically, only the head is eaten. The cauliflower head is composed of a white inflorescence meristem. Cauliflower heads resemble those in broccoli, which differs in having flower buds. Brassica oleracea also includes broccoli, brussels sprouts, cabbage, collard greens and kale, though they are of different cultivar groups. Perhaps the most popular among agricultural crops that produce edible flowers are the cauliflower and broccoli (Brassica oleracea) and globe artichoke (Cynara scolymus). There is a steady and high demand for their flowers and they are thus grown intentionally in commercial scale. They are commonly used worldwide as flower vegetables, that is, their main usage is in culinary preparation including salads. However, their economic parts consist not only of pure flowers but rather of the entire immature inflorescence or flower cluster. So, edible part of cauliflower is inflorescence and not bud, leaves and fruit. 
Therefore, the correct answer is option C.

The trunk of the pseudostem in the species of Musa is made of tightly packed layers of leaf sheaths. The inflorescence grows horizontally from the trunk where  individual white to yellow flowers grow geotropically negative.
Since, both male and female flowers are present in a single inflorescence. Female flowers located near the base develops into a fruit and male flowers are found between leathery bracts and the inflorescence is called as a spadix.Therefore, the correct answer is option C.

A cyathium is one of the specialised pseudanthia (false flowers) forming the inflorescence of plants in the genus Euphorbia (Euphorbiaceae). A cyathium consists of five bracteoles. These are small, united bracts, which form a cup-like involucre. Their upper tips are free and in the beginning cover the opening of the involucre. These alternate with five (1 to 10) nectar glands, which are sometimes fused. One extremely reduced female flower standing in the centre at the base of the involucre, consisting of an ovary on a short stem with pistil and surrounded by five groups of extremely reduced male flowers, which each consist of a single anther on a stem. The flower-like characteristics of the cyathia are underlined by brightly coloured nectar glands and often by petal-like appendages to the nectar glands, or brightly coloured, petal-like bracts positioned under the cyathia. The paired petal-like bracts of Euphorbia section Goniostema are called as cyathophylls. Here female to male flower ratio is 1.
Therefore, the correct answer is option C.

Cyathium - Here, the inflorescence is highly reduced. It has a cup shaped receptacle formed by the fusion of five bracts. On the surface of this cup, generally a yellow coloured nectar secreting gland is present. A single female flower arises from the centre of the cup. It is highly reduced and is borne on a long stalk. The male flowers are highly reduced and are produced in a scorpioid manner from the axil of each bract e.g., Euphorbia pulcherrima.

Anatomical studies of the dicot root shows that the cortex forms the ground tissue and is responsible for the storage of photosynthetic products and uptake of water and minerals. Secondary growth also occurs in the roots and when the secondary xylem and phloem enlarge, the vascular cambium is sandwiched. The expansion of the secondary xylem, phloem and epidermis causes the cortex to slough away. 
Thus, the correct answer is option B.