Unit 3 Honey Bee
Class 10 Science Notes
Table of Contents (Unit 3 Honey Bee)
1. Summary: Honey Bee
1.1 Important Terms & Definitions
Apiculture
Definition: The scientific method of rearing honey bees for honey and wax.
Social Insect
Definition: Insects that live in a colony, share food, and have a distinct division of labor (e.g., Bees, Ants).
Polymorphism
Definition: The existence of different forms or distinct castes within the same species (Queen, Drone, Worker).
Nuptial Flight
Definition: The mating flight taken by a virgin queen and drones in the air.
Parthenogenesis
Definition: The process of reproduction where an embryo develops from an unfertilized egg (how Drones are born).
Metamorphosis
Definition: The distinct changes in body form during the life cycle (Egg $\rightarrow$ Larva $\rightarrow$ Pupa $\rightarrow$ Adult).
Royal Jelly
Definition: A highly nutritious milky white secretion produced by the hypopharyngeal glands of worker bees, fed to the queen and queen larvae.
Bee Bread
Definition: A mixture of honey and pollen fed to worker and drone larvae.
Swarming
Definition: The natural process where an old queen leaves the hive with a group of workers to establish a new colony.
Absconding
Definition: The migration of the entire colony from one place to another due to unfavorable conditions.
1.2 Biological Principles
While this biological chapter does not have mathematical formulas, it follows specific genetic principles regarding sex determination:
Sex Determination “Formula”
Fertilized Egg (2n) $\rightarrow$ Female (Queen or Worker)
Unfertilized Egg (n) $\rightarrow$ Male (Drone) – This is Parthenogenesis.
Caste Determination “Formula” (Dietary)
Female Larva + Royal Jelly (throughout development) = Queen
Female Larva + Bee Bread (after 3 days) = Worker
1.3 Morphology (External Structure)
The body of a bee is divided into three parts:
Head
Contains a pair of compound eyes (vision), three ocelli (light intensity), a pair of antennae (smell/feel), and mouthparts (chewing and lapping).
Thorax
The middle part consisting of three segments. It bears three pairs of legs and two pairs of wings.
Note: Worker bees have pollen baskets on their hind legs.
Abdomen
The posterior part.
Workers: Possess wax glands and a sting (modified ovipositor).
Queen: Large abdomen for egg storage; sting is used only against rival queens.
Drone: Blunt abdomen, no sting.
1.4 The Three Castes (Comparison)
| Feature | Queen | Drone | Worker |
|---|---|---|---|
| Gender | Fertile Female | Fertile Male | Sterile Female |
| Origin | Fertilized Egg | Unfertilized Egg | Fertilized Egg |
| Size | Largest (Long abdomen) | Medium (Broad body) | Smallest |
| Lifespan | 2–5 years | ~2 months (dies after mating) | 6 weeks – 6 months |
| Function | Lay eggs, manage colony | Mate with the queen | Foraging, cleaning, nursing, guarding |
| Food | Royal Jelly | Bee Bread | Bee Bread |
1.5 Life Cycle
Honey bees undergo Complete Metamorphosis consisting of four stages:
Egg: Pearl white, elongated. Hatch in 3 days.
Larva: White, worm-like, eating stage. Moults several times.
Pupa: Resting stage inside a capped cell. Development of organs occurs here.
Adult: Emerges by cutting the wax cap.
Duration of Life Cycle (in days):
Queen: ~15–16 days
Worker: ~21 days
Drone: ~24 days
Life Cycle of Honey Bee
1.6 Economic Importance
Honey: Rich in carbohydrates, vitamins, and minerals. Used as food and in Ayurvedic medicine.
Beeswax: Used in cosmetics (creams, lipsticks), candles, and polishes.
Pollination: Bees are the most important agents of cross-pollination, significantly increasing agricultural crop yields.
Medicinal: Bee venom (Apisoxin) is used to treat arthritis.
1.7 Quick Chapter Review (Short & Sweet)
This chapter focuses on the Honey Bee, a beneficial social insect belonging to the Phylum Arthropoda. They live in highly organized colonies featuring a strict division of labor among three castes: the Queen (the mother of the hive), the Drones (males for mating), and the Workers (females that do all the work).
Morphologically, their body is segmented into a head, thorax, and abdomen. A unique feature of their biology is that males are born from unfertilized eggs (parthenogenesis), while females come from fertilized eggs. Whether a female becomes a Queen or a Worker depends entirely on her diet (Royal Jelly vs. Bee Bread).
The bee life cycle is complete, moving from Egg $\rightarrow$ Larva $\rightarrow$ Pupa $\rightarrow$ Adult. While we value them for producing honey and beeswax, their most critical contribution to nature and humans is pollination, which ensures the survival of many plants and food crops.
2.1 Choose the correct options for the following questions:
(a) Which bee contains only 16 chromosomes?
Reason: The drone bee develops from an unfertilized egg through a process called parthenogenesis. Therefore, it is haploid and contains only one set of chromosomes ($n=16$), whereas Queen and Worker bees are diploid ($2n=32$).
(b) From where is royal jelly produced?
Reason: Royal jelly is a creamy, nutritious substance secreted by the hypopharyngeal glands located in the head of worker bees (specifically nurse bees), which is used to feed the queen and young larvae.
(c) Which bee is formed when the larva is fed royal jelly continuously?
Reason: A fertilized egg develops into a female larva. If this larva is fed royal jelly throughout its developmental stage, it develops reproductive organs and becomes a fertile Queen bee. (Workers are fed royal jelly only for the first three days).
(d) Which stage of the bee is shown in the given diagram?
(e) Why is honey bee called a social insect?
Reason: Honey bees are called social insects because they live together in a highly organized family group called a colony, where there is a distinct division of labour among the members (Queen, Drone, and Worker).
(f) When the pollen baskets in the legs of worker bees are broken by certain means, which of the following functions cannot be performed by them?
Reason: The pollen basket (corbicula) is a structure on the hind legs of worker bees specifically designed to carry pollen pellets. If it is broken, they cannot collect and transport pollen.
(g) Which of the following is the characteristic of the drone bee?
Reason: Drones are male bees, which are haploid (16 chromosomes). They are fertile (capable of mating with the queen) and are generally broader/medium-sized and hairy compared to workers.
(h) Where does the queen bee store the sperms received from the drone bee after the nuptial flight?
Reason: After the nuptial flight (mating flight), the queen stores the millions of sperm she received from drones in a special pouch in her abdomen called the spermatheca (sperm sac), where they remain viable for years.
2.2 Differentiate:
(a) Drone bee and Worker bee
| Characteristic | Drone Bee | Worker Bee |
|---|---|---|
| 1. Gender | Male bee. | Sterile female bee. |
| 2. Origin | Develops from an unfertilized egg (Parthenogenesis). | Develops from a fertilized egg. |
| 3. Chromosomes | Haploid (16 chromosomes). | Diploid (32 chromosomes). |
| 4. Function | Its main function is to mate with the queen. | Performs all hive duties (cleaning, collecting nectar, guarding, etc.). |
| 5. Body Structures | Lacks pollen basket, sting, and wax glands. | Possesses pollen basket, sting, and wax glands. |
(b) Queen bee and Worker bee
| Characteristic | Queen Bee | Worker Bee |
|---|---|---|
| 1. Fertility | Fertile female (can lay eggs). | Sterile female (cannot lay eggs). |
| 2. Size | Largest bee in the hive (1.5 to 2 cm). | Smallest bee in the hive (1.2 to 1.5 cm). |
| 3. Food (Larval) | Fed royal jelly continuously during the larval stage. | Fed royal jelly for only 3 days, then bee bread. |
| 4. Function | Lays eggs and controls the hive. | Performs all labour work except reproduction. |
| 5. Lifespan | Lives for about 2 to 5 years. | Lives for 6 weeks (active season) to 6 months (winter). |
(c) Queen bee and Drone bee
| Characteristic | Queen Bee | Drone Bee |
|---|---|---|
| 1. Gender | Female. | Male. |
| 2. Origin | Develops from a fertilized egg. | Develops from an unfertilized egg. |
| 3. Chromosomes | Diploid (32 chromosomes). | Haploid (16 chromosomes). |
| 4. Sting | Has a sting (modified ovipositor) used to kill rivals. | Does not have a sting. |
| 5. Role | To lay eggs and lead the colony. | To mate with the virgin queen. |
2.3 Give reason:
(a) Honey bee is called a social insect.
Reason: Honey bees are called social insects because they live in a well-organized colony where thousands of bees work together. They exhibit a distinct division of labour where different castes (Queen, Drone, Worker) perform specific duties for the survival and welfare of the entire colony, rather than living solitary lives.
(b) Pasture land is required for bee farming.
Reason: Pasture land containing abundant flowering plants (mustard, sunflower, buckwheat, fruits) is required for bee farming because bees need a continuous source of nectar and pollen to produce honey and survive. The quality and quantity of honey depend directly on the availability of flowers (pasturage) in the surrounding area.
(c) Drone dies after mating.
Reason: A drone dies after mating because, during the process of copulation with the queen in the air (nuptial flight), its reproductive organ (penis) gets stuck inside the queen’s body. When they separate, the drone’s reproductive parts and internal organs are torn out, causing immediate death.
(d) Bees are multipurpose insects.
Reason: Bees are considered multipurpose insects because they provide numerous benefits:
• They produce honey, which is a nutritious food and medicine.
• They produce beeswax, used in cosmetics and candles.
• They play a crucial role in pollination, significantly increasing agricultural crop yields.
• They produce other useful substances like propolis and royal jelly.
2.4 Answer the following questions:
(a) Write the various types of bee found in the hive.
Answer: The three types of bees found in a hive are:
1. Queen Bee: The single fertile female and mother of the colony.
2. Drone Bee: The fertile males.
3. Worker Bee: The sterile females who perform all the work.
(b) What is the function of the drone bee?
Answer: The primary function of the drone bee is to mate with the virgin queen bee during the nuptial flight to fertilize her. They also help in maintaining the warmth of the hive during the brood rearing season.
(c) If the queen bee dies for some reason, who will control the hive?
Answer: If the queen bee dies, the worker bees will select a young larva (less than 3 days old) that hatched from a fertilized egg. They will feed this larva exclusively with royal jelly to develop it into a new queen. Once the new queen emerges and mates, she will take control of the hive.
(d) How does the queen bee control other members of the hive?
Answer: The queen bee controls other members of the hive by producing a special chemical substance (pheromone) called “queen substance” or mandibular pheromone. The scent of this pheromone inhibits the ovarian development of worker bees and keeps the colony cohesive and working systematically.
(e) Write the uses of honey.
Answer: The uses of honey are:
• It is used as a highly nutritious food rich in carbohydrates, vitamins, and minerals.
• It is used in Ayurvedic and herbal medicines to treat coughs, colds, and digestive issues.
• It is used as a natural sweetener in candies, cakes, and breads.
• It functions as an antioxidant and helps strengthen the immune system.
(f) Describe the structure of the queen bee.
Answer: The queen bee is the largest bee in the colony, with a body length of about 1.5 to 2.0 cm. She has a long, tapering abdomen that extends beyond her wings. She possesses a sting (ovipositor) which she uses only against rival queens. She lacks pollen baskets, wax glands, and strong mandibles, as she does not forage or build combs.
(g) Mention the functions of the worker bee.
Answer: The functions of the worker bee include:
• Cleaning: Cleaning the hive and brood cells.
• Nursing: Feeding royal jelly to the queen and larvae.
• Construction: Producing wax and building honeycomb cells.
• Guarding: Protecting the hive from enemies using their sting.
• Foraging: Collecting nectar, pollen, propolis, and water from flowers.
• Temperature Control: Fanning wings to maintain hive temperature.
(h) Explain how the division of labour occurs in bees.
Answer: Division of labour in bees is primarily based on their caste and age (polyethism):
Queen: Sole responsibility is reproduction (laying eggs).
Drone: Sole responsibility is mating.
Workers: Perform duties based on age:
• Days 1-3: Cleaning the hive.
• Days 4-6: Feeding older larvae (honey/pollen).
• Days 7-12: Producing royal jelly and feeding young larvae/queen.
• Days 12-18: Producing wax and building combs.
• Days 18-21: Guarding the hive entrance.
• Days 22+: Foraging outside for nectar and pollen until death.
(i) Explain the life cycle of honey bee with a diagram.
Answer: The life cycle of a honey bee is completed in four stages:
1. Egg: The queen lays a small, white, elongated egg in the honeycomb cell. It takes about 3 days to hatch.
2. Larva: A worm-like, legless larva hatches. It eats voraciously (royal jelly initially, then bee bread). This stage lasts about 5.5-7 days depending on the caste.
3. Pupa: The larva spins a cocoon and becomes a pupa inside the sealed cell. During this resting stage, adult structures (legs, wings, eyes) develop.
4. Adult: The fully formed bee chews the wax cap and emerges from the cell.
Total time: Queen (16 days), Worker (21 days), Drone (24 days).
Life Cycle of Honey Bee
(j) What is the process called in which a drone is developed from an unfertilized egg?
Answer: The process is called Parthenogenesis. It is a form of asexual reproduction where an embryo develops from an unfertilized egg cell.
(k) When a farmer practises bee farming, then income of other farmers in that locality also increases. Justify your reason.
Answer: When a farmer practices bee farming, the bees travel to nearby fields to collect nectar and pollen. During this process, they transfer pollen grains between flowers, facilitating cross-pollination. This significantly increases the fruit and seed set (crop yield) of mustard, buckwheat, fruits, and vegetables grown by neighboring farmers. Thus, the neighboring farmers get a better harvest and higher income without any extra cost.
(l) Due to the problem of pasture land in the beekeeping area, beekeepers shifted the bees from there. After that, there was a reduction in the yield of mustard crops of nearby farmers. Based on this, explain the relationship between beekeeping and agricultural production.
Answer: This scenario illustrates the symbiotic (mutual) relationship between honey bees and agricultural crops. The reduction in mustard crop yield occurred because the bees were no longer there to perform pollination.
For Agriculture: Crops depend on bees for effective pollination to produce seeds and fruits. Without bees, fertilization in plants is reduced, leading to lower yields.
For Beekeeping: Bees depend on agricultural crops (flowers) for nectar and pollen to produce honey and survive.
Conclusion: Beekeeping and agriculture are complementary; bees boost crop production, and crops provide food for bees.
(m) Look at the concept map and complete it.