Define Genotypes and Phenotypes

Question

Living things have traits, or characteristics. A dog might have curly brown fur. A giraffe has spots. A zebra has stripes. Phenotypes are the observable traits of organisms. Although you can observe a phenotype, the information that determines the phenotype cannot be easily observed.

Chromosomes are microscopic structures in the nucleus of cells. Each chromosome contains genes. A gene is a section of DNA with information about a specific trait. The genes for a trait are not all the same. There are variations, or different forms. The different forms of a gene are called alleles.

Organisms have two copies of each chromosome. For any given trait, the chromosomes might have the same form of the gene, or the same allele. They might have different alleles. The combination of alleles an organism has is its genotype. Letters are used to describe genotypes. For example, in pea plants, a capital T is used to indicate an allele for tallness. A lowercase t in
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Answer 1

Here are some concise notes summarizing the key points about genotypes and phenotypes:

Genotypes and Phenotypes Notes

1. Traits:

• Traits are characteristics of living organisms.
• Examples:
  • Curly brown fur in dogs
  • Spots on giraffes
  • Stripes on zebras

2. Phenotype:

• Definition: The observable traits of an organism.
• Phenotypes can include physical features, behaviors, and other characteristics that can be seen or measured.
• Although phenotypes are observable, the underlying genetic information that determines them is not directly visible.

3. Chromosomes:

• Microscopic structures located in the nucleus of cells.
• Contain genes that carry the information for specific traits.

4. Genes:

• Definition: Sections of DNA that provide instructions for specific traits.
• Genes can have variations, which are different forms called alleles.

5. Alleles:

• Definition: Different forms of a gene.
• Possible for an organism to have two copies of the same allele or two different alleles for a trait.

6. Genotype:

• Definition: The combination of alleles an organism has for a specific trait.
• Typically described using letters (e.g., uppercase and lowercase).
• Example: In pea plants,
  • T (capital T) represents an allele for tallness.
  • t (lowercase t) could represent an allele for shortness.
• Genotypes can be homozygous (same alleles) or heterozygous (different alleles).

Summary

• Phenotype = observable traits (what you see).
• Genotype = genetic makeup (the underlying alleles).
• Genes and alleles are crucial for understanding how traits are inherited and expressed in organisms.