Question

Arrange the following animals in increasing order of haploid number of chromosomes
A. Cat
B. Cattle
C. Chicken
D. Dog
E. Horse
Choose the correct answer from the options given below

• A. C < A < B < E < D
• B. D < E < C < A < B
• C. E < D < C < B < A
• D. A < B < E < C < D

Hint:

Haploid Chromosome Numbers ($n$):
Cat ($n=19$) $<$ Pig ($n=19$) $<$ Sheep ($n=27$) $<$ Cattle/Goat ($n=30$) $<$ Horse ($n=32$) $<$ Dog/Chicken ($n=39$).

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Comparative veterinary cytogenetics: haploid chromosome complements ($n = 2n/2$) across domestic mammalian and avian species.
Key Formula or Approach:
\[ \text{Cat } (n=19) < \text{Cattle } (n=30) < \text{Horse } (n=32) < \text{Dog/Chicken } (n=39) \]

Step 2: Detailed Explanation:
Diploid ($2n$) and haploid ($n$) chromosome numbers:
1. A. Cat (Felis catus): $2n = 38 \implies \mathbf{n = 19}$.
2. B. Cattle (Bos taurus indicus): $2n = 60 \implies \mathbf{n = 30}$.
3. E. Horse (Equus caballus): $2n = 64 \implies \mathbf{n = 32}$.
4. C. Chicken D. Dog:
- Dog (Canis familiaris): $2n = 78 \implies \mathbf{n = 39}$.
- Chicken (Gallus gallus): $2n = 78 \implies \mathbf{n = 39}$.
Arranging in increasing order: Cat (19) $<$ Cattle (30) $<$ Horse (32) $<$ Chicken (39) $\le$ Dog (39) (Sequence: A $<$ B $<$ E $<$ C $<$ D).

Step 3: Final Answer:
Thus, the correct increasing order is A < B < E < C < D, corresponding to option (D).