Problem 7 - Campbell Biology

Question

Application/Analysis The black dots that cover strawberries are actually fruits formed from the separate carpels of a single flower. The fleshy and tasty portion of a strawberry derives from the receptacle of a flower with many separate carpels. Therefore, a strawberry is (A) a simple fruit with many seeds. (B) both a multiple fruit and an accessory fruit. (C) both a simple fruit and an aggregate fruit. (D) both an aggregate fruit and an accessory fruit.

Step-by-Step Solution

Answer

The correct answer is (D) both an aggregate fruit and an accessory fruit.

Step 1: Understand the Definition of Each Term

Begin by understanding the key terms in the options provided: simple fruit, aggregate fruit, multiple fruit, and accessory fruit. A simple fruit develops from a single ovary, an aggregate fruit develops from multiple ovaries of a single flower, a multiple fruit develops from multiple flowers, and an accessory fruit includes other floral parts in addition to the ovary.

Step 2: Analyze the Characteristics of a Strawberry

A strawberry consists of fleshy and tasty portions derived from the receptacle of a flower with many separate carpels. The black dots that cover strawberries are actually the fruits themselves, formed from separate carpels of a single flower.

Step 3: Identify the Type of Fruit Based on Carpels

Since a strawberry develops from many separate carpels of a single flower, it fits the definition of an aggregate fruit.

Step 4: Identify if It Is an Accessory Fruit

A strawberry includes parts other than the ovary in its development, specifically the receptacle of the flower. This makes it an accessory fruit.

Step 5: Combine the Identified Characteristics

Given the above analysis, a strawberry is both an aggregate fruit and an accessory fruit.

Step 6: Select the Correct Answer

After reviewing the options and the analysis, we can conclude that the correct answer is (D) both an aggregate fruit and an accessory fruit.

Key Concepts

aggregate fruit

Aggregate fruits come from a single flower that has multiple ovaries. Each ovary develops into a small fruit called a drupelet or a carpel. These small fruits cluster together to form the aggregate fruit.
One example of an aggregate fruit is a strawberry. The tiny black dots on the strawberry's surface are individual fruits formed from separate ovaries. Each of these tiny fruits contains a seed.
Another example is a raspberry. When you eat a raspberry, you are actually eating many tiny fruits clustered together.
Key points to remember:

• Develop from multiple ovaries of one flower.
• Each ovary forms a small fruit that clusters together.
• Examples include strawberries, raspberries, and blackberries.

accessory fruit

Accessory fruits involve more than just the ovary in their development. Parts of the flower that are not directly involved in ovary development, like the receptacle, contribute to the fleshy part of the fruit.
Strawberries are also accessory fruits. Their tasty portion comes from the flower's receptacle, not the ovary. This is why strawberries are both aggregate and accessory fruits.
Other examples include apples and pears. In these fruits, the fleshy part we eat comes mostly from the floral parts surrounding the ovary.
Key points to remember:

• Includes parts beyond the ovary in development.
• Fleshy part of the fruit often comes from floral parts like the receptacle.
• Examples include strawberries, apples, and pears.

simple fruit

Simple fruits develop from a single ovary of a single flower. They can be fleshy or dry when mature.
A common example of a simple fruit is a cherry. It comes from a single ovary and develops into one fleshy fruit with a single seed.
Other examples include apples (though partly accessory), tomatoes, and peaches.
Key points to remember:

• Develop from a single ovary of one flower.
• Can be fleshy like cherries or dry like nuts.
• Examples include cherries, tomatoes, and peaches.

multiple fruit

Multiple fruits form from the ovaries of many flowers that grow closely together. Each flower's ovary develops into a fruit, and these small fruits join together to form one large fruit.
An example of a multiple fruit is a pineapple. Each segment of a pineapple represents a flower's ovary that turned into a small fruit. These small fruits fuse together to create the full pineapple.
Another example is figs. Inside a fig, multiple tiny flowers produce tiny fruits that together form the whole fig.
Key points to remember:

• Form from multiple flowers growing closely together.
• Ovaries of these flowers develop into small fruits that join together.
• Examples include pineapples and figs.