The total number of genes in humans is far less (< 25,000) than the previous estimate (upto 1,40,000 genes). C

NCERT Exemplar · Q55

Q. The total number of genes in humans is far less (< 25,000) than the previous estimate (upto 1,40,000 genes). Comment.

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Concept understanding — Scale And Scope

Let’s start with something you already know from daily life.

Imagine a small chai stall. The owner buys milk, tea leaves, sugar, and firewood. Every morning, she boils a small pot of milk, makes a few cups, and sells them. Now imagine a big tea company that runs a factory. It buys milk in tankers, tea leaves by the truckload, and uses industrial boilers. The company makes thousands of cups every hour.

The difference between the chai stall and the tea company is not just size. It is about two different kinds of advantage: scale and scope.

What is Scale?

Scale means doing more of the same thing. When a firm produces a larger quantity of a single product, its average cost per unit often falls. This happens because fixed costs — like rent, machinery, or a manager’s salary — get spread over more units. The chai stall pays the same rent whether it sells 50 cups or 100 cups. If it could sell 100 cups, the rent per cup would be half. That is the logic of economies of scale.

In the NCERT textbook (Class 11, Microeconomics, Chapter 3: Production and Costs), this is explained as the falling portion of the long-run average cost curve. As output increases, the firm can use more efficient technology, buy inputs in bulk at lower prices, and specialise labour. But scale has a limit. Beyond a point, diseconomies set in — coordination becomes harder, communication slows, and costs start rising again.

Important

Scale is about producing more of the same product to lower average cost. It is the reason big factories can sell goods cheaper than small workshops.

What is Scope?

Scope means doing more different things using the same resources. A firm enjoys economies of scope when it can produce two or more products together at a lower total cost than producing them separately.

Think of a dairy. It buys milk, processes it, and sells milk packets. But the same milk can also be turned into curd, butter, paneer, and cheese. The dairy already has the chilling plant, the pasteurisation equipment, the delivery trucks, and the sales network. Adding a new product — say, flavoured lassi — uses the same milk, the same factory, and the same distribution. The extra cost of making lassi is much smaller than starting a separate lassi company from scratch.

The NCERT textbook does not use the term “economies of scope” explicitly in the core microeconomics chapters, but the idea appears in the discussion of joint products and multi-product firms. In business studies (Class 12, Chapter 9: Financial Management), you see it indirectly when firms diversify into related products to use existing resources better.

Note

Scope is about producing different products together to share common inputs — raw materials, machinery, brand name, or distribution channels. It is why a company that makes soap also makes shampoo, and why a car company also makes spare parts.

Why It Matters

Scale and scope are not just textbook terms. They explain the structure of industries you see around you.

Scale explains why a single large steel plant can produce steel cheaper than a hundred small furnaces. It also explains why small shops survive — they offer personal service, location convenience, or customisation that a giant factory cannot.
Scope explains why a company like ITC sells everything from cigarettes to hotels to packaged foods. Each business shares some common resource — the brand, the distribution network, or the agricultural supply chain.

For a commerce student, understanding these concepts helps you answer questions like:

Why do firms grow bigger? …

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The Human Genome Project's comprehensive sequencing revealed that a surprisingly small fraction of our DNA codes for proteins, leading to a drastic downward revision of the estimated human gene count from over 1,00,000 to less than 25,000.

When the Human Genome Project (HGP) was launched in 1990, it was an ambitious undertaking to sequence the entire human genome. Before the project's completion, scientists often estimated the number of genes in humans to be very high, sometimes upwards of 80,000 to 1,40,000. This estimate was largely based on the perceived complexity of humans compared to simpler organisms, assuming a direct correlation between organismal complexity and the number of genes. The prevailing thought was that a highly complex organism like a human must possess a vast number of genes to orchestrate its intricate biological processes.

However, the actual data generated by the Human Genome Project presented a surprising revelation. As the genome was meticulously sequenced and analyzed, it became clear that the initial estimates were significantly inflated. The HGP, which provided the complete sequence of the human genome, allowed for a much more accurate identification and annotation of genes.

Important

The Human Genome Project's most striking finding was that less than 2 per cent of the human genome actually codes for proteins.

This discovery was a game-changer. If only a tiny fraction of our DNA codes for proteins, then the number of protein-coding genes must be far fewer than previously thought. The vast majority of the human genome consists of non-coding DNA sequences, including repetitive sequences, which do not directly translate into proteins. While these non-coding regions are now understood to play crucial roles in gene regulation, chromosomal structure, and evolution, they are not "genes" in the traditional sense of protein-coding units.

The revised estimate, as stated in NCERT, brought the total number of genes down to approximately 30,000. Further refinements and ongoing research have continued to refine this number, leading to current estimates of less than 25,000 genes. This drastic reduction in the estimated gene count fundamentally altered our understanding of human genetics for several reasons:

Precise Gene Identification: The HGP provided the empirical data needed to precisely identify the start and end points of protein-coding genes, distinguishing them from non-coding regions. Earlier estimates often relied on less precise computational predictions or extrapolations.
Challenging the "Gene Count = Complexity" Paradigm: The finding demonstrated that biological complexity does not solely depend on the sheer number of genes. Even simpler organisms, like the roundworm Caenorhabditis elegans, have a comparable number of genes (around 20,000), yet are far less complex than humans. …

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Q.The total number of genes in humans is far less (< 25,000) than the previous estimate (upto 1,40,000 genes). Comment.

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