Genetics Flashcards
Genetics
is the study of heredity. Genetics involves studying how traits are passed from parent to offspring.
Heredity
is the passing of traits from parents to offspring.
Traits
are the characteristics of an organism. Examples are eye color, freckles, height or dimples
Chromosomes
Chromosomes are thread-like structures in the nucleus of cells that carry genetic information. A chromosome consists of a long strand of DNA containing many genes.
DNA
Deoxyribonucleic acid (DNA) is a molecule made up of nucleotides that contains genetic information for cell growth, division and function.
Gene
A gene is a segment on a chromosome that determines a specific trait. Genes are the units of heredity.
allele
- a different form or version of a gene - alleles usually occur in pairs
dominant
- a gene variant that is expressed more strongly than other versions of the same gene - the dominant allele masks the effect of the recessive allele
recessive
a gene that is masked by a dominant gene, and is only expressed when two copies of the gene are present
genotype
- the genetic make up or code of an organism - Ex: BB, Bb, bb
phenotype -
the observable traits or physical appearance of an organism - Ex: brown eyes or blue eyes
Who is the father of genetics?
Gregor Mendel
What did Gregor Mendel Study?
Mendel studied how traits like flower color, seed shape, and plant height were inherited by plants. He used pea plants for his experiments.
homozygous
- If an organism has two of the same kind of gene for a trait, it is called pure or homozygous.
Example: Homozygous brown eyes (BB) ~ Homozygous blue eyes (bb)
heterozygous
An organism with two different alleles for a trait is called heterozygous or hybrid.
Example: A heterozygous tall plant (Tt) expresses the dominant allele (T or tall) and thus, is tall.
Why did Mendel choose pea plants for his experiments?
Mendel chose pea plants because they grow quickly, have many different traits, and can be easily cross-pollinated.
Why is Mendel’s work important?
Mendel’s discoveries helped us understand how traits are inherited and laid the foundation for the science of genetics. This helps us understand how traits pass from one generation to the next in all living things.
What did Mendel discover about how traits are passed down?
Mendel discovered that traits are passed from parents to offspring through specific patterns. He found that some traits are dominant, and others are recessive.
