Heredity
Frequently Asked Questions
Heredity is the process through which traits or characteristics are passed from parents to offspring via genes.
A gene is a segment of DNA on a chromosome that codes for a specific trait or protein.
A trait is any observable characteristic or feature of an organism, such as eye color or blood type, determined by genes.
Chromosomes are thread-like structures made of DNA and proteins, present in the nucleus of cells, that carry genetic information.
Genotype is the genetic makeup of an organism, representing the combination of alleles inherited from parents.
Phenotype is the observable physical or biochemical characteristics of an organism, determined by its genotype and environment.
Alleles are different forms of a gene that control the same trait and may result in variations within a population.
Inherited traits are passed through genes from parents to offspring; acquired traits result from environmental influences and are not inherited.
It states that two alleles for each trait separate during gamete formation, so each gamete gets only one allele.
Mendel’s law of independent assortment states that genes for different traits assort independently during gamete formation.
A monohybrid cross involves one trait, crossing two organisms that differ in that single trait, e.g., tall vs short pea plants.
A dihybrid cross studies two traits simultaneously, e.g., seed shape and color in pea plants.
A dominant trait expresses itself in the presence of another allele, while a recessive trait is masked when a dominant allele is present.
Tall stem in pea plants is a dominant trait over short stem.
The typical phenotype ratio in F2 generation of a monohybrid cross is 3:1 (three dominant : one recessive).
The F2 generation of a dihybrid cross typically shows a 9:3:3:1 phenotype ratio.
Sex determination is the process by which the sex of an organism is decided, usually by the combination of sex chromosomes (XX for female, XY for male in humans).
The father's sperm carries either X or Y chromosome. If X, offspring is female (XX); if Y, offspring is male (XY).
Mutation is a sudden change in the DNA sequence, which may lead to variations and sometimes diseases.
Examples include hemophilia, sickle cell anemia, and color blindness.
Genotype is the set of genes inherited, while phenotype is the expression of those genes as observable attributes.
Punnett Square is a diagrammatic device used to predict the outcome of genetic crosses.
Variation increases survival chances by allowing species to adapt to changing environments.
Mendel discovered the principles of dominance, segregation, and independent assortment.
A hybrid is the offspring resulting from the cross-breeding of genetically distinct individuals.
An organism that consistently yields progeny with the same traits when self-crossed is a true breeding or pure line.
Heredity principles are used in selective breeding to improve crop yield and disease resistance.
Mutation, genetic recombination, and sexual reproduction cause genetic variation.
While genes provide the blueprint, environmental factors such as nutrition, climate, and lifestyle influence the phenotype.
Pedigree charts are used to study the inheritance of traits across generations within families.
Meiosis produces gametes with half the chromosome number and leads to genetic diversity.
Genetic recombination and reduction division (chromosome number halved) happen during meiosis.
Mendel cross-pollinated pea plants with contrasting traits and analyzed the traits in successive generations, discovering foundational laws of genetics.
They inherit a mix of genes from each parent and experience genetic variation and recombination during gamete formation.
In codominance, two different alleles express themselves equally; for example, AB blood group in humans.
In incomplete dominance, the resulting phenotype is a blend of both parental traits, e.g., red and white flowers produce pink offspring.
Genetic disorders pass from parents to offspring through faulty genes, often following patterns like dominant or recessive inheritance.
DNA stores genetic information and directs the synthesis of proteins required for various functions in the body.
Biological evolution is the change in traits of populations over generations due to genetic variation and natural selection.
Acquired traits, gained during an individual's lifetime, are not inherited as they do not alter genetic material.
