Why is a flower biologically considered a reproductive unit rather than a vegetative branch?
The flower is the reproductive unit in angiosperms because it is structurally specialized and meant for sexual reproduction, housing the male (androecium) and female (gynoecium) reproductive organs.
Question 182 of 300
📘 CLASS XI
In which of the following inflorescence types would you expect to find the oldest flower at the base of the peduncle and the youngest bud at the apex?
In racemose inflorescences, flowers are borne in an acropetal succession, meaning the oldest flowers are at the base and younger flowers or buds are at the apex.
Question 183 of 300
📘 CLASS XI
If a flower can be divided into two similar halves only in a single specific vertical plane, which of the following is it, and what is its symmetry type?
A flower that is divisible into similar halves in only one vertical plane is zygomorphic, such as pea. Mustard is actinomorphic, and Canna is asymmetric because it cannot be divided into similar halves by any vertical plane through the centre.
Question 184 of 300
📘 CLASS XI
Consider the following structural terms and their descriptions: 1. Trimerous — Floral appendages in multiples of 3. 2. Tetramerous — Floral appendages in multiples of 4. 3. Pentamerous — Floral appendages in multiples of 5.
Which of these descriptions are correct?
A flower is described as trimerous, tetramerous, or pentamerous when its floral appendages are present in multiples of 3, 4, or 5 respectively.
Question 185 of 300
📘 CLASS XI
In a lily flower, the calyx and corolla are not distinct from one another. What is this consolidated accessory whorl called?
In flowers such as lily, the calyx and corolla are not distinct and are collectively called the perianth.
Question 186 of 300
📘 CLASS XI
Which of the following groups of plants matches this floral description: "Flowers are hypogynous, and the ovary is superior"?
Hypogynous flowers with superior ovaries are found in mustard, China rose, and brinjal. Plum, rose, and peach are perigynous, whereas guava, cucumber, and ray florets of sunflower are epigynous.
Question 187 of 300
📘 CLASS XI
Which of the following features represents the ray florets of a sunflower?
Epigynous flowers with inferior ovaries are found in guava, cucumber, and the ray florets of sunflower.
Question 188 of 300
📘 CLASS XI
If you find a flower with united sepals, what is the technical term for this calyx condition?
When the sepals of a calyx are united or fused, the condition is termed gamosepalous. If the sepals are free, it is called polysepalous.
Question 189 of 300
📘 CLASS XI
Match the following aestivation types with their correct definitions: 1. Valvate — Sepals or petals in a whorl touch each other at the margin without overlapping. 2. Twisted — One margin of the appendage overlaps that of the next one, and so on. 3. Imbricate — Margins overlap but not in any particular direction.
Which of these matches are correct?
All three definitions are correct and correspond exactly to valvate, twisted, and imbricate aestivation respectively.
Question 190 of 300
📘 CLASS XI
A student observes a flower where one margin of a petal overlaps the adjacent petal's margin, which in turn overlaps the next one, and so on. This pattern is seen in China rose, lady's finger, and cotton. What is this aestivation?
This is twisted aestivation, characterized by sequential, directional overlapping of sepals or petals, as seen in China rose, lady's finger, and cotton.
