Topic 7A: Genetics Flashcards
What is inheritance in genetics?
Inheritance is the process by which genetic information is passed from parent organisms to offspring, determining traits based on genetic material (DNA).
What is the law of segregation?
The law of segregation states that allele pairs separate during gamete formation, so each gamete carries only one allele for each gene.
What is the law of independent assortment?
The law of independent assortment states that genes for different traits are inherited independently of each other, as long as they are on different chromosomes.
What is the difference between dominant and recessive alleles?
A dominant allele is expressed in the phenotype even if only one copy is present, whereas a recessive allele is only expressed when two copies (homozygous) are present.
What is a genotype?
A genotype is the genetic makeup of an organism, referring to the specific alleles inherited for a particular trait.
What is a phenotype?
A phenotype is the observable characteristics or traits of an organism, resulting from the interaction of its genotype with the environment.
What is genetic linkage?
Genetic linkage occurs when genes located close together on the same chromosome tend to be inherited together during meiosis because they are less likely to be separated by crossing over.
What is crossing over?
Crossing over is the exchange of genetic material between homologous chromosomes during meiosis, which can lead to genetic variation by recombining alleles.
What is epistasis?
Epistasis occurs when one gene affects the expression of another gene, often masking or modifying the phenotype produced by the second gene.
What is an example of epistasis?
One example is the coat color in certain animals, where a gene for coat color might be affected by another gene that determines whether pigment is produced at all.
What is the Chi-squared test used for in genetics?
The Chi-squared test is used to compare observed genetic data with expected data to determine whether the differences are due to chance or a significant factor.
What is the null hypothesis in a Chi-squared test?
The null hypothesis in a Chi-squared test states that there is no significant difference between the observed and expected data, meaning any variation is due to random chance.
How is the Chi-squared statistic calculated?
The Chi-squared statistic is calculated using the formula:
where is the observed frequency (O), is the expected frequency (E), and the sum is taken across all categories.
What does a high Chi-squared value indicate?
A high Chi-squared value indicates a large difference between the observed and expected values, suggesting that the result is statistically significant and not due to chance.
How do you determine if the Chi-squared value is statistically significant?
You compare the Chi-squared value to a critical value from the Chi-squared distribution table, based on the degrees of freedom and chosen significance level (usually 0.05). If the Chi-squared value exceeds the critical value, the null hypothesis is rejected.
What is inheritance?
The process by which genetic traits are passed from parents to offspring through genetic material (DNA).
What is the Law of Segregation?
The principle that alleles for a gene separate during gamete formation, so each gamete carries only one allele for each gene.
What is the Law of Independent Assortment?
The principle that genes located on different chromosomes are inherited independently of one another during meiosis.
What is a Dominant Allele?
An allele that expresses its effect on the phenotype even when only one copy is present in a heterozygous individual.
What is a Recessive Allele?
An allele that only expresses its effect on the phenotype when two copies (homozygous) are present.
What is a genotype?
The genetic constitution of an organism, describing the specific alleles inherited for a given trait.
What is phenotype?
The observable characteristics of an organism resulting from the interaction of its genotype with the environment.
What is Genetic Linkage?
The tendency of genes located close together on the same chromosome to be inherited together due to reduced recombination during meiosis.
What is Crossing Over?
The exchange of genetic material between homologous chromosomes during meiosis, leading to genetic variation.
What is epistasis?
A genetic interaction where one gene affects the expression of another gene, often masking or modifying its phenotype.
What is the Chi-Squared Test?
A statistical test used to determine whether there is a significant difference between observed and expected genetic data.
What is Statistical Significance (Chi-Squared)?
When the Chi-squared value exceeds the critical value from the Chi-squared distribution table, it suggests that the observed differences are unlikely due to chance.
