Genetics Vocab
What is a gene?
a unit of DNA that contains instructions for building a specific protein or RNA molecule
What does a Punnett square predict?
the possible genotypes and phenotypes of offspring from a cross between two parents
What does DNA stand for?
deoxyribonucleic (dee-OK-see-ri-bo-new-klee-ik) acid
How do Genetics affect you?
profoundly influences your physical appearance, body functions, and even your behavior and predisposition to certain health conditions.
Name one example of a genetic disorder.
Down syndrome.
Define "dominant allele."
a variant of a gene that expresses its associated trait even when paired with a different allele
What is the probability of Bb x Bb having a bb child?
The probability of having a \(bb\) child when two \(Bb\) parents are crossed is \(\frac{1}{4}\) or \(25\%\).
Where is DNA found in a cell?
within the nucleus
What does it mean to inherit a trait?
a characteristic or feature is passed down from parents to offspring through genes, according to the rules of inheritance.
Is Down syndrome inherited or caused by a mutation?
not inherited in the classic sense
Define “genotype” vs. “phenotype.”
genotype is the genetic makeup of an organism, its DNA blueprint, while phenotype is the observable characteristics of that organism
What are the genotype ratios for AA x Aa?
Equal probability: Each of these combinations is equally likely to occur, resulting in a 1:1 ratio of AA to Aa genotypes.
What are the base pairs of DNA?
adenine (A), thymine (T), guanine (G), and cytosine (C)
How can we predict what traits we can get?
understanding how genes are passed down from parents to offspring
How is sickle cell anemia inherited?
autosomal recessive pattern
What is a recessive trait?
a characteristic that is expressed only when an individual has two copies of the recessive allele, meaning they inherit one from each parent
In Tt x Tt, what % will be tall if tall is dominant?
In a cross of Tt x Tt, 75% of the offspring will be tall if tall (T) is dominant to short (t).
What is a mutation?
a change in the DNA sequence of an organism's genes
What is selective breeding?
the process where humans choose which organisms (plants or animals) will reproduce, with the goal of developing organisms with specific, desired traits
Can carriers show symptoms of a disorder?
In most cases, carriers of a genetic condition do not exhibit symptoms themselves
What is homozygous and heterozygous?
homozygous describes an individual who has two identical alleles for a specific gene, while heterozygous describes an individual who has two different alleles for a specific gene
solve a cross of Rr x Rr.
RR Rr
Rr rr
Explain how a gene codes for a protein.
The DNA sequence is read in groups of three nucleotide bases, called codons, and each codon specifies a particular amino acid in a protein
What is genetic variation and why is it important?
Genetic variation is crucial for evolution because it provides the raw material for natural selection, allowing species to adapt and change over time.
Name a benefit and a risk of genetic testing.
it can provide individuals with information about their risk of developing certain diseases, allowing them to make informed decisions about their health and lifestyle