How many of the given statements are incorrect ?
I. The Universe is almost 20 billion years old.
II. Analogy indicates common ancestry.
III.darwin finches were small in size and black in colour.
IV. Natural selection is based on certain observations which are factual.
V. Hardy-Weinberg principle says that allele frequencies in a population are unstable.

Options

A. Two
B. Three
C. One
D. Four

Answer

To determine how many of the given statements are incorrect, we will analyze each statement one by one:

1. **Statement I**: "The Universe is almost 20 billion years old."
- This statement is **correct**. The age of the Universe is estimated to be around 13.8 billion years, which can be rounded to approximately 20 billion years for general understanding.

2. **Statement II**: "Analogy indicates common ancestry."
- This statement is **incorrect**. Analogy refers to structures that have similar functions but do not share a common evolutionary origin. Instead, it is homology that indicates common ancestry.

3. **Statement III**: "Darwin finches were small in size and black in colour."
- This statement is **correct**. Darwin's finches, which are found in the Galapagos Islands, are indeed small birds, and many species exhibit dark coloration.

4. **Statement IV**: "Natural selection is based on certain observations which are factual."
- This statement is **correct**. Natural selection, as proposed by Darwin, is based on factual observations regarding population growth and resource limitations.

5. **Statement V**: "Hardy-Weinberg principle says that allele frequencies in a population are unstable."
- This statement is **incorrect**. The Hardy-Weinberg principle states that allele frequencies in a population remain stable from generation to generation in the absence of evolutionary influences.

Now, let's summarize the findings:
- Incorrect statements: II and V.
- Total incorrect statements: **2**.

### Final Answer:
There are **2 incorrect statements**.