Question

Which of the following statements is INCORRECT regarding inheritance of traits? A. A mutation due to excessive amounts of ultraviolet light occurs in an unfertilized egg; this will affect the child who is born from that egg. B. The muscular strength gained by a weight lifter during his lifetime is inherited by his children. C. A green-feathered bird that survived all of the predators in the forest will pass on the green feather genes to its offspring. D. A flower with tasty nectar that is eaten by a butterfly is more likely to pass on its delicious genes through the pollen spread by the butterfly than one that is not tasty.

Short answer

Statement B is incorrect because acquired traits like muscular strength are not inherited.

Step-by-step solution

Analyze statement A

Statement A says that a mutation due to excessive amounts of ultraviolet light occurs in an unfertilized egg and this will affect the child born from that egg. Since mutations in gametes can be passed on to offspring, this statement is correct.

Analyze statement B

Statement B claims that the muscular strength gained by a weight lifter during his lifetime is inherited by his children. Acquired traits, like muscular strength gained through exercise, are not inherited because they do not affect the genes passed on to offspring. Thus, this statement is incorrect.

Analyze statement C

Statement C suggests that a green-feathered bird that survived predators in the forest will pass on the green feather genes to its offspring. This is correct as it is an example of natural selection where the genetic traits that help survival are passed on.

Analyze statement D

Statement D implies that a flower with tasty nectar is more likely to pass on its genes through pollen spread by a butterfly. This is correct because attracting pollinators can increase the chances of pollination and gene transfer.

Key concepts

Mutation

Mutations are changes in the DNA sequence. These changes can occur due to various factors such as radiation, chemicals, or errors during DNA replication.

When a mutation occurs in a germ cell (like an egg or sperm), it can be passed on to the offspring. This means that the child might inherit the genetic variation from the mutated egg or sperm.

However, if the mutation happens in a somatic cell (any cell other than sperm or egg cells), it will not be passed on to the next generation. Only mutations in the gametes can be hereditary.

This is why the mutation in the ultraviolet light-affected egg was considered correct in the exercise.

Acquired Traits

Acquired traits are characteristics or skills that an individual develops during their lifetime. These traits are not present in the individual's DNA and therefore cannot be passed on to the next generation.

Examples of acquired traits include:

• Muscular strength from exercise
• Knowledge or skills learned
• Scars from injuries

In the context of the exercise, the muscular strength gained by a weight lifter would not be passed to their children. This is because these traits don't change the genetic material in the gametes.

Natural Selection

Natural selection is the process by which individuals with traits that are better suited to their environment have a higher likelihood of surviving and reproducing. These advantageous traits are then passed on to the next generation.

Over time, natural selection can lead to the evolution of new species. For example:

• If a green-feathered bird can avoid predators more effectively, it is likely to survive longer and reproduce more.
• This bird's offspring will inherit the green feathers, enhancing their chances of survival.

This process was illustrated in the exercise by the green-feathered bird's ability to pass its genes to its offspring.

Pollination

Pollination is a crucial process for the reproduction of flowering plants. It involves the transfer of pollen from the male part of the flower (anther) to the female part (stigma).

Pollen can be spread in several ways:

• By wind
• By water
• By animals and insects, such as butterflies and bees

If a flower has traits that attract pollinators (such as tasty nectar), it increases the likelihood of transferring its pollen to other flowers. This enhances the chances of fertilization and gene dissemination.

The exercise example suggested that a flower with tasty nectar, which attracts butterflies, is more likely to pass on these favorable traits.