Amborellaceae, Aristolochiaceae, Illiciaceae and Winteraceae are four angiosperm families that, according to the APG IV system of classification, belong to the 'early diverging angiosperms'. The presence (V+) or absence (V-) of vessels in the xylem and the fusion of the carpels within the gynoecium are important angiosperm characters. 'A' and 'S' indicate apocarpous (or monocarpellary) and syncarpous condition of ovary, respectively. Which one of the following options correctly represents the characters found in the above families?

Correct option is B

Based on the APG IV classification system, the characteristics of each of the families are as follows:

• Amborellaceae has no vessels in the xylem (V-) and an apocarpous ovary (A), where the carpels are not fused. Amborellaceae is considered one of the most primitive angiosperm families, showing an early branching condition.
• Aristolochiaceae has vessels in the xylem (V+) and a syncarpous ovary (S), where the carpels are fused. This condition indicates a derived reproductive feature compared to Amborellaceae.
• Illiaceae has vessels in the xylem (V+) and an apocarpous ovary (A), reflecting a condition similar to Amborellaceae with respect to the ovary's structure, but with vessels in the xylem.
• Winteraceae lacks vessels in the xylem (V-) and has an apocarpous ovary (A), similar to Amborellaceae in terms of xylem and ovary structure.

Information Booster:

1. Amborellaceae shows V- (absence of vessels in the xylem) and A (apocarpous ovary), reflecting its primitive characteristics.
2. Aristolochiaceae shows V+ (presence of vessels) and S (syncarpous ovary), indicating a more derived state in terms of both xylem structure and reproductive system.
3. Illiaceae is similar to Amborellaceae in having an apocarpous ovary (A) but differs in having vessels (V+).
4. Winteraceae shows V- (absence of vessels) and A (apocarpous ovary), similar to Amborellaceae, but with a unique combination of traits.
5. The presence of vessels in the xylem is a key feature distinguishing between early and later diverging angiosperms.
6. The condition of the ovary (syncarpous or apocarpous) reflects differences in the structure of the gynoecium, with syncarpous being more derived.

Additional Information:

• Option 1: "Amborellaceae: V+, A; Aristolochiaceae: V+, A; Illiaceae: V+, A; Winteraceae: V-, S" is incorrect because Winteraceae has an apocarpous ovary (A), not syncarpous (S), and Amborellaceae lacks vessels (V-), not present (V+).
• Option 3: "Amborellaceae: V-, S; Aristolochiaceae: V-, S; Illiaceae: V+, S; Winteraceae: V-, A" is incorrect as Amborellaceae and Winteraceae do not have syncarpous ovaries (S).
• Option 4: "Amborellaceae: V+, S; Aristolochiaceae: V-, A; Illiaceae: V+, S; Winteraceae: V-, S" is incorrect because Amborellaceae lacks vessels (V-), and the reproductive structure does not align with the given conditions.