Which grasshoppers are male and female in the sex determination NEET 2026 question?
The 23-chromosome grasshoppers are male, and the 24-chromosome grasshoppers are female: option C. This sex determination NEET 2026 question gives individuals of one grasshopper species with either 23 or 24 chromosomes. Identify their sexes in that order.
The choices are:
This is a Biology single-correct question from Genetics and Evolution. The question bank classifies it as medium difficulty and sets an expected solving time of 30 seconds. That expectation comes from the question bank, not a measured student average.
Which sex-determination system applies to this grasshopper?
Grasshopper sex determination in this question follows the XX–XO system, the biological premise used in the official solution. A male has autosomes plus one X chromosome, called XO; a female has autosomes plus two X chromosomes, called XX. Establish these assignments before counting chromosomes.
O means the absence of a second sex chromosome. It is not another chromosome or a substitute name for Y. Therefore, XO contributes only one sex chromosome to the total.
The male and female have the same number of autosomes. Their total chromosome counts differ because the female has one extra X chromosome, not an extra autosome.
How do the totals of 23 and 24 account for every chromosome?
The one-X individual has the lower total, while the two-X individual has the higher total because their autosome counts are unchanged. Assign 23 to the male and 24 to the female, then check the autosomes.
For the 23-chromosome individual, subtract its one X chromosome:
For the 24-chromosome individual, subtract its two X chromosomes:
The complete complements are:
Both calculations leave the same autosome count. The 22 autosomes are derived from the supplied totals and XX–XO system, not an extra fact to memorise. They are not a universal chromosome count for every grasshopper species.
Why is option C the correct ordered answer?
Correct answer: C, males and females, respectively. The stem gives 23 first and 24 second, so the required sequence is male first and female second. Reversing that order gives the wrong option even if you know the biology.
Use this checking chain:
The autosome calculation verifies the identification. The official method remains recognition of XX–XO, not guessing sex from an odd or even chromosome total.
Why does option A fail in the XX–XO system?
Option A comes from reversing the biological assignments: incorrectly giving the male XX and the female XO. With the same 22 autosomes, that mistake produces a 24-chromosome male and a 23-chromosome female. In the stem’s order, this becomes “female, male”, exactly option A.
The error is in the biological premise, not in subtraction. Repair it by writing the correct assignments before attaching either total:
Reject the shortcut “males always have fewer chromosomes”. The difference here follows specifically from XX–XO. In an XX–XY system, each sex has two sex chromosomes, so that shortcut does not apply. Identify the system first and compare totals second.
How do you solve related XX–XO gamete and fertilisation questions?
Use the derived 22 autosomes for this same species, halve the autosome count during normal gamete formation, then track X separately. These are original related practice questions, not additional verified NEET PYQs. Each answer uses the chromosome counts established above.
What chromosome totals can male gametes carry in this species?
Answer to Question 1: Male gametes can carry 12 or 11 chromosomes. The male has 22 autosomes and one X chromosome. Each normal sperm receives 11 autosomes:
An X-bearing sperm receives the X chromosome; a sperm without X receives no sex chromosome:
The zero represents absence. It does not represent an “O chromosome”.
How many chromosomes does a normal egg carry in this species?
Answer to Question 2: A normal egg carries 12 chromosomes. The female has 22 autosomes and two X chromosomes. Normal meiosis gives each egg half the autosomes and one X:
What offspring result when each sperm type fertilises an egg?
Answer to Question 3: An X-bearing sperm produces an XX female; a sperm without X produces an XO male. Every normal egg contributes 12 chromosomes, including one X.
Both combinations restore 22 autosomes. Cover these answers and rebuild both fertilisation totals, counting autosomes first and X chromosomes second.
Next step: the past-paper archive on NEET JEEnius AI and search past NEET papers by year, subject or chapter, each with a worked solution (100 free searches a month).
Keep going with Co-ordination Compounds NEET 2002: One Unpaired Electron.
Frequently asked questions
Is a grasshopper with 23 chromosomes male or female?
In the given XX–XO grasshopper question, the individual with 23 chromosomes is male, while the one with 24 is female. The male has 22 autosomes plus X; the female has 22 autosomes plus XX. In the stated order, the correct answer is option C: male and female, respectively.
What does O mean in XO sex determination?
O means the absence of a second sex chromosome. It is neither a separate chromosome nor another name for Y. An XO male therefore has only one sex chromosome, X.
How many chromosomes do grasshopper sperm and eggs have?
For the species in this question, with 23-chromosome males and 24-chromosome females, normal sperm carry either 12 or 11 chromosomes. Both sperm types have 11 autosomes, but only the 12-chromosome type carries X. Every normal egg carries 12 chromosomes: 11 autosomes plus X.
Do male grasshoppers always have 22 autosomes?
No, 22 autosomes is the count derived for the species in this question, not a universal count for grasshoppers. Subtracting one X from the male total of 23 gives 22 autosomes. Subtracting two X chromosomes from the female total of 24 gives the same result.
Do males always have fewer chromosomes than females?
No, that shortcut does not apply across sex-determination systems. In the XX–XO system used here, the male has one fewer chromosome because it has only one X. In an XX–XY system, both sexes have two sex chromosomes.