CBSE Questions for Class 11 Medical Biology Morphology Of Flowering Plants Quiz 13 - MCQExams.com

• The Euphorbiaceae are mostly monoecious herbs, shrubs, and trees, sometimes succulent and cactus-like, comprising one of the largest families of plants with about 300 genera and 7,500 species that are further characterized by the frequent occurrence of milky sap. The leaves are mostly alternate but may be opposite or whorled and they are simple, or compound, or sometimes highly reduced. Stipules are generally present but may be reduced to hairs, glands or spines. The flowers are unisexual and usually actinomorphic. They may be highly reduced by suppression of parts, in the extreme form consisting of a naked stamen as a male flower and a naked pistil as a female flower. 
  
• A specialized type of miniature inflorescence called a cyathium occurs in about 1,500 species comprising the genera Euphorbia and Chamaesyce. The cyathium consists of a single naked pistillate flower surrounded by cymes of naked staminate flowers, each consisting of a single stamen.
• These flowers are all enclosed in a cup-like involucre that typically is provided with peripheral nectaries and petaloid appendages such that the whole aggregation closely resembles a single flower.
  

• The primary root, or radicle, is the first organ to appear when a seed germinates. It grows downward into the soil, anchoring the seedling from the embryonic root (radicle), which grows out of the seed after the seed has absorbed water. This is the primary root of a new plant.
  
• A fibrous root system is the opposite of a taproot system. It is usually formed by thin, moderately branching roots growing from the stem
  
• Stilt roots are the adventitious roots that help in supporting the plant body. Also known as support roots. These roots develop from the basal nodes of the main stem.
  
• A taproot is a large, central, and dominant root from which other roots sprout laterally. Typically a taproot is somewhat straight and very thick, is tapering in shape, and grows directly downward. Taproot, the main root of a primary root system, growing vertically downward.
  

• Inflorescence refers to the arrangement of group or cluster flowers on a stem.
  
• In an acropetal arrangement of flowers, the young flowers and buds are formed at the top of the stalk and the older flowers are formed at the bottom, this type of flowering arrangement pattern is called Racemose inflorescence.
  
• So, the correct answer is 'The acropetal arrangement of flowers on peduncle'.

$$\textbf{Correct option: A}$$

$$\textbf{Solution:}$$

Option A:

$$\bullet$$ $$Clerodendron$$ is the genus of flowering plants belonging to $$Lamiaceae$$ family (Mint family).

$$\bullet$$ The flowers of genus $$Clerodendron$$ exhibit cymose type of inflorescence in which the older flowers are present at the top position whereas the younger flowers are present at the inflorescence base.

$$\bullet$$ The main axis stops growing when a flower is born at the tip of this axis.

$$\bullet$$ Peripheral flowers open first in the plants belonging to $$Clerodendron$$ genus.

Hence the correct option is option A.

• The stalk holding the complete inflorescence and bearing the flowers or fruit, in a flowering plant is known as the peduncle. 
• The pedicle is the stem that attaches a single flower. 
• The petiole is the stalk that attaches a leaf to the stem and the leaflet of a pinnately compound leaf is called pinna. 

• Zygomorphic symmetry, also known as bilateral symmetry occurs in a flower through which it can pass only one plane of symmetry that will divide it into two parts.
• The Fabaceae or Leguminosae, commonly known as the legume, pea, or bean family are a large and economically important family of flowering plants which has a zygomorphic flower.
  
• Pea, bean, Cassia and Gulmohar belong to Fabaceae.

Brassica oleracea var. capitata, the common name is cabbage. Cabbage is a typical cool season crop grown for the thickened vegetative bud called as head. It is one of the most  popular and widely grown vegetables and has occupied second position in production after potato. It is a rich source of vitamin A, C and mineral including potassium, calcium, sodium and iron.