Inheritance, Variation and Evolution Principles of Inheritance Inheritance refers to the passing of genetic information from parents to offspring. This is contr...
Inheritance refers to the passing of genetic information from parents to offspring. This is controlled by DNA molecules that carry genes. Genes exist in pairs called alleles, which can be dominant or recessive. Genetic crosses can be predicted using Punnett squares.
Problem: If a red flower (RR) is crossed with a white flower (rr), what are the possible genotypes and phenotypes in the offspring?
Solution:
Variation refers to the differences between individuals within a species. Genetic variation arises from mutations or recombination of alleles during sexual reproduction. Environmental variation is caused by differing external factors.
Natural selection is the gradual process by which biological traits become more or less common in a population based on their advantages or disadvantages. It is one of the key mechanisms of evolution, first proposed by Charles Darwin. Evidence for evolution includes fossils, antibiotic resistance, and comparative anatomy.
Speciation is the process by which new species arise from existing ones due to reproductive isolation and genetic divergence over many generations.
Humans can artificially influence inheritance and evolution through selective breeding programs or direct genetic modification. Applications include improved crop yields and breeding livestock. However, ethical concerns exist regarding genetic engineering of organisms.