Heredity and Evolution Mind Map

Heredity is the passing of traits from parents to their children through genes.

In answers, mention both inheritance and parent to offspring transfer. If the question asks for resemblance, connect it directly to genes.

A gene is a small functional part of DNA on a chromosome that carries information for a trait.

When writing an answer, say gene is a unit of inheritance and mention that it is located on a chromosome.

A dominant trait is the trait that appears even when only one dominant allele is present.

When a question gives one capital and one small letter, check which trait is dominant and then write the visible trait.

A recessive trait is the trait that appears only when both alleles are recessive.

If the question mentions a recessive trait, check whether both alleles must be the same small letter before deciding the phenotype.

The monohybrid ratio is the expected ratio of traits or genotypes when only one character is studied in a cross.

For a monohybrid cross of two heterozygous parents, remember 1:2:1 for genotype and 3:1 for phenotype.

Sex determination is the process by which the sex of an offspring is decided at fertilisation.

Always write XX for female and XY for male in humans. Mention that the father's sperm determines the final combination.

Variation means differences among individuals of the same species.

When answering, separate inherited variation from environmental variation. This makes your answer more complete and more accurate.

Natural selection is the process in which organisms with useful variations survive and reproduce more successfully in a particular environment.

When the question mentions better survival and more offspring over time, connect the answer to natural selection.