Genetics Flashcards
(44 cards)
What is an allele?
One of two or more versions of a genetic sequence at a particular region on a chromosome
Alleles can result in different traits expressed in an organism.
What is an autosome?
Any chromosome that is not a sex chromosome
Autosomes make up the majority of human chromosomes.
Define codominance.
A type of inheritance in which two alleles of the same gene are expressed separately to yield different traits in an individual
Example: AB blood type in humans.
What is complete dominance?
When one allele completely dominates or takes control over another
In complete dominance, the dominant allele’s trait is expressed in the phenotype.
What does the term dominant refer to in genetics?
The relationship between two versions of a gene where one is always shown
Dominant alleles mask the effects of recessive alleles.
What is a generation in the context of genetics?
A successive stage in the natural descent of organisms
Each generation can show variations in traits due to genetic recombination.
What is a genotype?
The genetic makeup of an organism
Genotype determines the potential traits of an organism.
What does heterozygous mean?
Having different alleles for a particular trait
Example: one dominant and one recessive allele.
What does homozygous mean?
Having the same alleles for a particular trait
Can be either two dominant or two recessive alleles.
What is a hybrid?
The offspring resulting from combining the qualities of two organisms of different varieties, usually through sexual reproduction
Hybrids often exhibit traits from both parent organisms.
Define incomplete dominance.
A form of gene interaction in which both alleles of a gene are partially expressed, resulting in an intermediate phenotype
Example: pink flowers resulting from red and white parent flowers.
What is the Law of Independent Assortment?
Two different genes assort independently into gametes
This law explains how different traits are passed independently of one another.
What is the Law of Segregation?
The principle that each pair of alleles for a trait segregates, or separates, during gamete formation
This ensures that offspring receive one allele from each parent.
What are multiple alleles?
More than two allelic forms within a population
Example: ABO blood types in humans.
What is a pedigree?
A diagram of family history that uses standardized symbols
Pedigrees are used to track genetic traits through generations.
Define phenotype.
The physical properties of an organism
Phenotype is influenced by genotype and environmental factors.
What is a Punnett square?
A table summarizing possible combinations of maternal alleles with paternal alleles
It is a tool used to predict the probability of offspring genotypes.
What does purebred mean?
No mixture of other blood through generations
Purebred organisms have consistently inherited traits.
What is a recessive trait?
A trait that is expressed only when the genotype is homozygous
Recessive traits can be hidden by dominant traits.
What are sex-linked traits?
Traits that are influenced by genes carried on sex chromosomes
These traits often show different patterns of inheritance in males and females.
What does DNA carry?
Genetic information
DNA is the molecule that holds the instructions for the development and functioning of living organisms.
What are genes?
Parts of DNA that code for traits
Genes are segments of DNA that determine specific characteristics or traits.
What are chromosomes?
Mature DNA structure
Chromosomes are structures within cells that contain DNA and are involved in the transmission of genetic information.
