Selina Concise Solutions for ICSE Class 9 Biology Chapter 4 The Flower

Exercise 1

Question A:
Answer: 1. (d) large colourful bracts
2. (d) It has all the four whorls.
3. (c) Ovary
4. (c) Ovule
5. (d) Androecium and gynoecium
These answers highlight the essential reproductive parts and structural variations of flowers. Understanding these parts helps us identify how different plants reproduce and attract pollinators.
Teacher's Tip: Remember the "Big Four" whorls: Sepals, Petals, Stamens, and Carpels!
Exam Tip: For MCQ questions, always write the full option text, not just the letter.

Question B.1:
Answer: (a) Polyadelphous - (i) Bombax
(b) Pollen grains - (ii) Pollen sac
(c) Free petals - (iii) Polypetalous
(d) Non-essential - (iv) Calyx, corolla
(e) Sweet fragrant fluid - (v) Nectar
This matching exercise connects biological terms to their specific functions and examples in nature. It shows how flower structures are adapted to help in the process of making seeds.
Teacher's Tip: "Poly" means many, so poly-petalous means many free petals!
Exam Tip: Rewrite matching pairs side-by-side in your answer sheet to make it easier for the examiner to read.

Question C.1:
Answer: (a) Incomplete flower - If one or more sets of floral structures are missing, the flower is called incomplete flower. E.g. American elm.
(b) Staminate flower - A unisexual flower which contains only the stamens, i.e., male parts of a flower is called male or staminate flower. E.g. Eastern cottonwood.
(c) Pistillate flower - A flower which contains only the carpels, i.e., female parts of a flower is called female or pistillate flower. E.g. Date palm.
(d) Bisexual flower - A flower which contains both stamens and carpels is called bisexual or hermaphrodite flower. E.g. Hibiscus.
Flowers can be categorized based on whether they have all four parts or just specific reproductive ones. This diversity allows plants to use different methods, like wind or insects, for pollination.
Teacher's Tip: Think "Staminate" for "Stamen" (Male) and "Pistillate" for "Pistil" (Female).
Exam Tip: Always provide a specific example like Hibiscus or Date palm to make your definition complete.

Question C.2:
Answer: (a) Flower - Flower is a specialized shoot in which the leaves are modified into floral structures.
Inflorescence - Inflorescence is the mode of arrangement of flowers on the axis of the plant.
(b) Petals and Petaloid sepals:
Petals - Petals are non-essential parts of a flower which help in protection of reproductive parts and make the flower attractive for pollination.
Petaloid sepals - Undifferentiated petals and sepals together form the perianth. When perianth is non-green, it is called a petaloid.
A single flower is a structure, while inflorescence is how a group of flowers is organized on a stem. Petals are usually the colorful parts we see, while petaloid sepals look just like petals even though they are technically sepals.
Teacher's Tip: "Inflorescence" is like the "Flower Layout" on the plant's branch.
Exam Tip: When asked to distinguish between terms, always use a clear comparison format or a table.

Question C.3:
Answer: (a) Placenta: Location: Cushion or swollen region in the ovary. Function: Gives origin to ovules.
(b) Thalamus: Location: Tip of the flower stalk. Function: Bears all the parts of the flower.
(c) Anther: Location: Part of the stamen. Function: Produces male gametes or pollen grains.
(d) Stigma: Location: Terminal knob-like part. Function: Serves as the landing place for pollen grains during pollination.
Every part of the flower has a specific spot and a vital job in the life cycle of a plant. For example, the stigma must be at the top to easily catch pollen drifting in the wind or carried by bees.
Teacher's Tip: The "Thalamus" is like the "Table" that holds all the flower parts!
Exam Tip: Always mention both the location and the function when asked about a specific plant part.

Question C.4:
Answer: (a) The androecium of pea flower is diadelphous because the filaments of anther are united in two bundles. In case of pea, out of ten, nine stamens form a staminal tube while one is free.
(b) Ray florets of sunflower are neuters because both male and female reproductive organs are lacking or absent.
(c) Salvia sepals are petaloid because the three sepals are united and are red in colour like petals. Hence, they are undifferentiated from the petals.
(d) China rose stamens are epipetaloid because they arise from the base of the petals.
These specific adaptations in flowers like the pea or China rose show how diverse plant structures can be. These features often help in specific types of pollination or protect the reproductive organs.
Teacher's Tip: "Diadelphous" means "two groups" - just like a pair of bundles!
Exam Tip: When giving reasons, use the word "because" to clearly link the scientific fact to the flower's characteristic.

Question D.1:
Answer: 1. Polyandrous: When the stamens of a flower are free, the condition is called polyandrous.
2. Monadelphous: When the filaments of anthers in a flower are fused into one group, the condition is called monadelphous.
3. Diadelphous: When the filaments of anthers in a flower are fused into two groups, the condition is called diadelphous.
4. Polyadelphous: When the filaments of anthers in a flower are fused into more than two groups, the condition is called polyadelphous.
The way stamens are grouped or fused tells us a lot about the family a flower belongs to. These arrangements ensure that pollen is released effectively for successful reproduction.
Teacher's Tip: Use prefixes: Mono = 1, Di = 2, Poly = many.
Exam Tip: Draw simple sketches of these stamen arrangements to illustrate your answers during the exam.

Question D.2:
Answer: (a) China rose: Monadelphous
(b) Bombax: Polyadelphous
(c) Pea: Diadelphous
These examples help connect the scientific definitions to real flowers we see in gardens. Each of these plants has a unique way of organizing its reproductive parts.
Teacher's Tip: Remember the "Pea-Di" connection - Pea flowers are always Diadelphous!
Exam Tip: Associate one classic example with each scientific term for quick recall during tests.

Question E.1:
Answer: (a) The flower is of Sweet pea.
(b) Standard: Outermost petal which is large and broad
Wings: The two lateral petals are in the form of wings
Keel: Two wings enclose two inner petals which unite to form a keel
The Sweet pea flower has a very distinct shape with specialized petals that guide pollinators. This unique structure, often called "papilionaceous," is typical for the pea family.
Teacher's Tip: Think of the petals as a "Standard" flag, "Wings" of a plane, and a "Keel" like a boat.
Exam Tip: Be sure to describe the relative positions of the standard, wings, and keel petals.

Question E.2:
Answer: 1: Anther; 2: Filament: 3: Ovule: 4: Placenta; 5: Stigma; 6: Style; 7: Ovary; 8: Petal; 9: Sepal; 10: Receptacle/Thalamus
Labeling helps identify the anatomy of a flower, showing where the male and female parts are located. Knowing these parts helps in studying how pollination and fertilization occur inside the flower.
Teacher's Tip: Follow the path of the pollen: Stigma -> Style -> Ovary.
Exam Tip: Practice drawing and labeling a simple flower to get perfect scores on diagram-based questions.

Question E.3:
Answer: (a) Figure A represents stamen. Stamens collectively form Androecium.
(b) Contents of the pollen sacs in B are male gametes.
(c) The contents of the pollen sacs would come out through agents like air, wind, insects leading to pollination in flowers.
The androecium is the collective term for all the male parts of the flower. Pollination occurs when these male gametes travel from the stamen to reach a female stigma.
Teacher's Tip: "Andro" refers to male, so "Androecium" is the male part of the flower's house!
Exam Tip: State that pollination is the "transfer" of pollen for a scientifically accurate answer.

Question E.4:
Answer: When a flower arises in the axil of a leaf-like structure, this structure is known as bract. Because bracts are large and brightly coloured structures, they are often mistaken for petals. This helps to attract insects for pollination.
Bracts are special leaves that take on a colorful appearance to help the flower. In plants like Bougainvillea, the "petals" you see are actually these colorful bracts.
Teacher's Tip: If it's a "fake petal" leaf at the base of a flower, it's a bract!
Exam Tip: Always define bracts as "leaf-like structures" to distinguish them from true petals.

Question E.5:
Answer: Monadelphous: Filaments of the anthers in a flower are fused into one group. Example: Hibiscus.
Diadelphous: Filaments of the anthers in a flower are fused into two groups. Example: Pea.
Polyadelphous: Filaments of the anthers in a flower are fused into more than two groups. Example: Bombax.
This summary explains how the filaments of the stamens can be united in different ways. These groupings are important identifiers for botanists when classifying different plant species.
Teacher's Tip: Use "Hibiscus = 1 group, Pea = 2 groups, Bombax = Many groups" as a memory shortcut.
Exam Tip: Presenting your answer in a table format is the best way to earn full marks for comparison questions.