Inheritance Variation And Evoloutiom Flashcards
What is the basic unit of heredity?
Gene
True or False: Alleles are different forms of the same gene.
True
What is the genotype of an organism?
The genetic makeup of an organism.
Fill in the blank: The observable characteristics of an organism are known as its __________.
Phenotype
What is the purpose of meiosis?
To produce gametes with half the number of chromosomes.
What is a dominant allele?
An allele that expresses its trait even in the presence of a recessive allele.
What is a recessive allele?
An allele that only expresses its trait when two copies are present.
True or False: A homozygous organism has two identical alleles for a trait.
True
What is a phenotype ratio?
The ratio of different phenotypes produced in a genetic cross.
In a dihybrid cross, how many different phenotypes can be produced?
Four
What does the term ‘polygenic inheritance’ refer to?
Inheritance of traits controlled by two or more genes.
Fill in the blank: The __________ is the physical location of a gene on a chromosome.
Locus
What is a Punnett square used for?
To predict the genotypes and phenotypes of offspring from a genetic cross.
True or False: Mutation is a change in the DNA sequence.
True
What is natural selection?
The process where organisms better adapted to their environment tend to survive and produce more offspring.
What is speciation?
The formation of new and distinct species in the course of evolution.
Fill in the blank: The __________ theory explains how species evolve over time.
Evolution
What is genetic drift?
A change in allele frequencies in a population due to random sampling.
True or False: Genetic variation is essential for a population’s adaptability.
True
What is the role of chromosomes in inheritance?
Chromosomes carry genes that are passed from parents to offspring.
What is a karyotype?
A visual representation of an individual’s chromosomes.
Fill in the blank: The process of cell division that results in two identical daughter cells is called __________.
Mitosis
What type of inheritance pattern does blood type follow?
Codominance and multiple alleles.
What is the significance of the Hardy-Weinberg principle?
It provides a mathematical model to study genetic variation in a population.
True or False: All mutations are harmful.
False
What is a sex-linked trait?
A trait associated with a gene that is carried only by the male or female parent.
Fill in the blank: The __________ is a group of individuals of the same species that live in the same area and interbreed.
Population
What is an example of a trait that exhibits incomplete dominance?
Flower color in snapdragons (red x white = pink).
What is the role of DNA in inheritance?
DNA stores and transmits genetic information.
True or False: Evolution can occur in a single generation.
False
What is the difference between artificial selection and natural selection?
Artificial selection is human-directed breeding, while natural selection is driven by environmental pressures.
What is a phenotype that results from a heterozygous genotype?
It can display the dominant trait.
Fill in the blank: The __________ is the genetic makeup of an organism, while the phenotype is the expression of that genotype.
Genotype
What is the primary source of genetic variation in populations?
Mutation
What does the term ‘adaptive radiation’ refer to?
The diversification of a group of organisms into forms filling different ecological niches.
True or False: All individuals in a population are genetically identical.
False
What is a trait that is controlled by multiple genes called?
Polygenic trait
What is the significance of the fossil record in understanding evolution?
It provides evidence of past life forms and how they have changed over time.
Fill in the blank: The study of the distribution of species and ecosystems in geographic space and through geological time is known as __________.
Biogeography
What is meant by ‘survival of the fittest’?
It refers to the idea that individuals who are better adapted to their environment are more likely to survive and reproduce.
What are homologous structures?
Anatomical features in different species that are similar due to shared ancestry.
True or False: The process of evolution is slow and gradual.
True
What is a common example of a sex-linked disorder?
Hemophilia
What is the role of the environment in natural selection?
It determines which traits are advantageous for survival and reproduction.
Fill in the blank: __________ is the process by which organisms change over time through adaptations.
Evolution
What is the difference between a phenotype ratio and a genotype ratio?
Phenotype ratio refers to the observable traits, while genotype ratio refers to the genetic makeup.
What is the function of a test cross?
To determine the genotype of an organism displaying a dominant phenotype.
True or False: Genetic variation is essential for evolution to occur.
True
What does ‘fitness’ refer to in an evolutionary context?
The ability of an organism to survive and reproduce in its environment.
What is an example of a trait that shows epistasis?
Coat color in Labrador retrievers.
Fill in the blank: The __________ theory of evolution suggests that species evolve in rapid bursts followed by long periods of stability.
Punctuated equilibrium
What is a phenotype that is influenced by both genetics and environment?
Height in humans.
What is the purpose of genetic counseling?
To provide information and support regarding genetic conditions and inheritance.
True or False: The environment does not influence gene expression.
False
What is the significance of Charles Darwin’s theory of natural selection?
It provided a scientific explanation for the diversity of life on Earth.
Fill in the blank: The observable traits of an organism are referred to as its __________.
Phenotype
What is the primary function of ribonucleic acid (RNA) in cells?
To transfer genetic information from DNA for protein synthesis.
What is the significance of recombinant DNA technology?
It allows for the manipulation of DNA to create genetically modified organisms.
What is a common method for determining genetic relationships among species?
DNA sequencing.
True or False: All mutations are beneficial to an organism.
False
What is the role of the Y chromosome?
It determines male sex characteristics.
What is the significance of the genetic code?
It dictates how sequences of nucleotides in DNA are translated into proteins.
What is an example of a trait influenced by environmental factors?
Skin color in humans.
True or False: Evolution can be observed directly in short-lived organisms.
True
What is a genetic marker?
A specific DNA sequence that can be used to identify individuals or species.
Fill in the blank: Genetic __________ is the variation of genes within a population.
Diversity
What is the term for a change in the frequency of a gene variant in a population over time?
Evolutionary change
What is a common technique used for genetic engineering?
CRISPR-Cas9
True or False: All traits are inherited according to Mendel’s laws.
False
What is the term for the physical expression of a trait?
Phenotype
Fill in the blank: The __________ is responsible for carrying genetic information from one generation to the next.
DNA
What is the role of epigenetics in inheritance?
It studies how external factors can modify gene expression without changing the DNA sequence.
