Male fruit flies can be identified from females by:

Question

BlackTom AI · Accepted Answer

Male Drosophila melanogaster are distinguished by a distinctive black-tipped abdomen that is a reliable external sexual dimorphism.

1. Relevant knowledge points and concepts
- Sexual dimorphism in Drosophila: males and females differ in abdomen coloration and shape, presence of sex combs on male forelegs, and genital morphology.  
- The black posterior band or “black tip” on the abdomen is characteristic of adult males.  
- Sex combs are rows of thick bristles on the first tarsal segment of the male foreleg (not extra leg segments).  
- Eye color (red) is not typically sexually dimorphic in wild-type flies.

2. Step-by-step reasoning
- Compare each option to known diagnostic characters.  
- Option “Black tip on abdomen”: matches the well-documented darker, rounded, black-pigmented terminal abdominal segments of males.  
- Option “Extra set of leg segments”: anatomically incorrect — males do not have additional leg segments; they have sex comb bristles on existing segments.  
- Option “Darker red eyes”: eye color is generally the same in both sexes for wild-type strains, so this is not a reliable sexing trait.  
- Option “All of these options”: only true if each individual option were correct, which they are not.

3. Calculations/intermediate steps
- No numerical calculations apply; the logical elimination above serves as the intermediate reasoning.

4. Why the correct answer is correct
- The black-tipped abdomen is externally visible and widely used to sex Drosophila: males show a darkly pigmented terminal abdominal tergites (A5–A6) and a rounded abdomen, whereas females typically have lighter, striped abdominal segments and a more pointed abdomen.

5. Why other options are incorrect
- “Extra set of leg segments”: false—males have specialized bristles (sex combs), not extra segments.  
- “Darker red eyes”: not a sexual dimorphism in normal strains.  
- “All of these options”: false because two constituent statements are incorrect.

6. Conclusion
The correct answer is “Black tip on abdomen,” which matches the provided answer.

Male fruit flies can be identified from females by:单项选择题

类似问题

The visible expression of sexual dimorphism between male-sexed and female-sexed individuals is referred to as what?

19. Which of these statements about the size of the Murray Cod is true?

A significant difference in the appearance of the two sexes within a species is called a(n) and is often the result of sexual selection.

Which of the following statements is wrong about Drosophila melanogaster males

What was the world's first widely adopted biodiversity policy?

The aim of the Paris Agreement is to ensure that the earth’s preindustrial temperature is not exceeded by more than º Celsius.

The IPCC's mission is to Blank ______.

Why have most international agreements for environmental protection been based on the honor system?

更多留学生实用工具

智能学习助手

风格化写作助手

论文查重助手

文献引用助手

课堂转译助手

课堂笔记助手

Quiz搜索助手

学校历年真题

智能刷题助手

智能匹配练习

希望你的学习变得更简单