Question

The phenotype is determined by the combination of alleles or genes at a certain locus. Natural selection allows animals to naturally adapt to their environments. Dane recently crossed two of his shorthorn cattle. His calf had both red and white in its coat. Dane’s offspring is a result of codominance. A scientist is analyzing a cell under a microscope. He notices it only has half of a paired chromosome. The cell is a result of nondisjunction. An animal has a genetic mutation. The mutation occurred during replication. Somatic cells divide during mitosis, while gametes undergo meiosis. If two identical animals are raised separately but do not look exactly the same in a year, factors like environmental influences contribute to this phenomenon.

Answer 1

The phenotype of an organism is the physical expression of its genetic makeup or genotype, which can exhibit dominant or recessive trait expression. Environmental factors also influence phenotypes, and natural selection can impact which alleles are more common in a population. Mendelian genetics, dominant and recessive traits, mutations, and environmental factors all contribute to the diversity of phenotypes.

Step-by-step explanation:

Understanding Phenotypes and Genotypes

Two alleles for a given gene in a diploid organism interact to produce physical characteristics, which constitute an organism’s phenotype. Meanwhile, an organism's genotype is its underlying genetic makeup, composed of both expressed and non-expressed alleles. Mendel’s hybridization experiments offer insights into how different genotypes can produce the same phenotype. For example, crossing true-breeding plants with yellow and green pods, respectively, all F₁ hybrids exhibited the yellow pod phenotype, despite having different genotypes from the yellow pod parent plant, as revealed in their F₂ progeny.

Different genetic expressions, such as dominant and recessive alleles, can dictate phenotypic outcomes. In cases of codominance, both alleles are equally expressed, like in certain cattle where red and white colors may appear together in the coat. Environmental influences also play a significant role in shaping phenotypes, contributing to differences in identical organisms raised in varying settings.

Natural selection favors advantageous traits, leading to an increase in allele frequency for those traits within a population over time. However, variations such as mutations can introduce new genetic material into a population, sometimes resulting in observable changes.