Question

Nurturing behavior in rats can produce calmer, less stressed offspring because genes that are involved in stress reactions are turned off. This is an example of a. epigenetics. b. genetic engineering. c. recessive genes. d. dominant genes.

Short answer

The answer is a. epigenetics.

Step-by-step solution

Understanding Epigenetics

Epigenetics is the study of changes in organisms caused by modification of gene expression rather than alteration of the genetic code itself. This means how genes are 'turned on' or 'off' as a result of external or environmental factors.

Analyzing Genetic Engineering

Genetic engineering involves directly manipulating an organism's genes using biotechnology. This typically involves making direct changes to the DNA sequence, rather than affecting how genes are expressed externally like epigenetics.

Exploring Recessive Genes

Recessive genes are those that do not express their effects unless two copies are present in an individual. This is about hereditary traits, and not about genes being turned on or off through behavioral influences.

Understanding Dominant Genes

Dominant genes express their traits even when only one copy is present in an individual. This concept, similar to recessive genes, relates to hereditary inheritance rather than gene expression changes due to behavior.

Comparing with the Context

The context involves nurturing behavior affecting gene expression related to stress—an external influence changing how genes are expressed. This aligns with epigenetics, where gene expression is altered by environmental factors.

Key concepts

Gene Expression

Gene expression is the process by which information from a gene is used in the synthesis of a functional gene product, typically a protein. In simple terms, it determines whether a gene is 'active' or 'inactive'.
When a gene is expressed, it means that the protein or RNA it codes for is being made and used by the cell. However, not all genes are always active. It's a bit like having a vast library of books, but only reading or using the information from a few of them at any given time.

• Genes can be turned 'on' or 'off' based on the needs of an organism.
• This switching can be influenced by various factors, including environmental changes or diet.

When the environment influences which genes are expressed, it's a part of the broader field known as epigenetics. This allows organisms to respond to changes in their environment without altering the underlying DNA sequence.

Environmental Influence

Environmental factors can have a profound effect on gene expression, sometimes more than genetic predispositions themselves.
This means that, by changing environmental factors, the potential expression of certain genes can be modified. For example, when a rat pup receives nurturing care - like licking or grooming from its mother - this environmental stimulus can activate genes that help in reducing stress responses.

• Factors like temperature, nutrient availability, and social interactions can influence gene expression.
• Environmental stimuli can lead to chemical modifications around genes, making them more or less likely to be expressed.

Understanding environmental influence is essential as it demonstrates the flexibility of biological systems in adapting to changes without changing the fundamental genetic code. This aspect shows how organisms can turn specific genes on or off in response to the world around them.

Nurturing Behavior

Nurturing behavior, especially in animals like rats, plays an essential role in shaping gene expression patterns. When a mother rat licks and grooms her pups, she provides a nurturing environment that activates specific genes necessary for stress regulation.
This nurturing doesn't alter the pups' DNA; instead, it affects which genes are expressed, leading to calmer and more stress-resilient offspring.

• Nurturing behavior acts as an environmental stimulus that modifies gene expression without altering genetic sequences.
• Such behavior can lead to long-lasting effects on the offspring, benefitting them throughout their lives.

This fascinating intersection between biochemistry and behavior underscores the importance of the environment on gene expression. It confirms that nurturing is not just a social or emotional construct, but a biological catalyst for gene expression.