Question

An organism’s traits are determined by the specific combination of inherited ________. a. cells b. genes c. proteins d. chromatids

Short answer

An organism's traits are determined by the specific combination of inherited \(genes\). Genes, as segments of DNA, carry information for making proteins which give an organism its specific characteristics or traits. The other options (cells, proteins, chromatids) are related to genetic inheritance but do not directly determine traits.

Step-by-step solution

Identify the correct answer

In this case, an organism's traits are determined by the specific combination of inherited genes.

Explain why genes are the correct choice

Genes are segments of DNA that carry the information for making proteins, which in turn give an organism its specific characteristics, or traits. Genes are passed from parent to offspring through sexual or asexual reproduction. Therefore, the combination of inherited genes determines an organism's traits.

Explain why the other options are incorrect

a. Cells: Cells are the basic functional units of living organisms, but they are not the factor that directly determines traits. Cells contain DNA, which includes genes, but it is the genes themselves that determine traits. c. Proteins: While proteins do play a crucial role in an organism's traits, they are not directly inherited. Instead, they are synthesized based on the information carried by genes. It is the genes' information that dictates which proteins are made and how they function in the organism. d. Chromatids: Chromatids are duplicated copies of a chromosome, which contain genes. Although chromatids are involved in the inheritance process, they are not the fundamental units that carry the information for traits; genes are. Thus, the correct answer is: b. genes

Key concepts

genes

Genes are the basic units of heredity that play a critical role in determining the characteristics and functions of an organism. They are made up of DNA, which encodes the instructions to produce proteins needed by a cell to perform essential functions. Every organism inherits a set of genes from its parents, and these genes dictate to a great extent the inherited traits an organism possesses.

Each gene acts as a blueprint for a specific protein or function within the organism. The sequence of DNA in each gene determines the order of amino acids in a protein, which ultimately influences how the protein will function.

• A single gene can influence multiple traits.
• Some traits require multiple genes to work together.
• Genes can interact differently depending on environmental factors.

This genetic information is passed down during reproduction, ensuring that offspring carry a combination of traits from both parents.

inheritance

Inheritance is the process by which genetic information is passed from parents to their offspring. This transfer of genes from one generation to the next is vital for maintaining the continuity of species and is governed by well-understood biological principles.

There are two main types of inheritance:

• Sexual Inheritance: Involves the combination of genes from two parents, adding diversity within a species through genetic recombination. This process occurs during the formation of gametes, where half of each parent's genome is passed to the offspring.
• Asexual Inheritance: Offspring inherit a direct copy of their single parent's genetic material. It leads to very little genetic variation since the offspring are clones of the parent.

Understanding the rules of inheritance, such as those outlined by Gregor Mendel—known as Mendelian inheritance, helps illuminate how traits are distributed and expressed in organisms.

organism traits

Traits are the observable features or characteristics of an organism, such as eye color, height, or blooming patterns in plants. These are determined by the organism's genotype, which is the specific combination of inherited genes.

Traits can be:

• Dominant: Expressed when at least one dominant allele is present. For example, if the trait for brown eyes is dominant, an organism with one or two copies of the gene for brown eyes will have brown eyes.
• Recessive: Displayed only when both alleles for a trait are recessive. An organism must inherit two recessive alleles for the recessive trait to manifest.
• Polygenic: Influenced by multiple genes making the prediction and variation of traits like height or skin color very complex.

Traits are not solely determined by inherited genes. Environmental factors can also heavily influence trait expression, giving rise to differences even among organisms with similar genetic backgrounds.