1. Why are individuals different from one another? 2. How are traits passed on from one generation to the next? 3. How many chromosomes do humans have?
Answer (1)
Individuals are different from one another because of variations in their DNA. DNA is the blueprint of life and determines how organisms look and function. Each person has unique DNA, except for identical twins. Differences can arise from genetic variations, such as mutations or the mixing of genes during the formation of reproductive cells, as well as from environmental factors that influence development and characteristics.
Traits are passed from one generation to the next through genes. Genes are segments of DNA located on chromosomes, which carry instructions for making proteins and determining traits. During reproduction, parents pass their genes to their offspring through reproductive cells: eggs and sperm. Each parent contributes half of their chromosomes to form a complete set in the child, ensuring traits from both sides are inherited.
Humans have 46 chromosomes in total, arranged in 23 pairs. Each parent contributes one chromosome to each pair, so offspring receive one set of 23 chromosomes from their mother and another set of 23 from their father.
