Variations In Living Organisms Flashcards
What is variation in living organisms?
Variation refers to the differences in physical, genetic, or behavioral traits among individuals of the same species.
True or False: All variations in living organisms are genetic.
False
What are the two main types of variation?
Genetic variation and environmental variation.
Fill in the blank: Genetic variation is primarily caused by ________.
mutations
Define genetic variation.
Genetic variation refers to the differences in the genetic makeup of individuals within a population.
Which process leads to genetic variation during reproduction?
Meiosis
What is the role of mutations in variation?
Mutations introduce new alleles into a population, contributing to genetic diversity.
True or False: Environmental factors can influence phenotypic variation.
True
What is phenotypic variation?
Phenotypic variation refers to the observable differences in traits among individuals.
Which type of variation can be influenced by climate, diet, and lifestyle?
Environmental variation
What is the significance of variation in a population?
Variation increases the chances of survival and adaptation to changing environments.
Fill in the blank: The process of natural selection acts on ________ variation.
phenotypic
What is a mutation?
A mutation is a change in the DNA sequence that can lead to new traits.
Multiple Choice: Which of the following is NOT a type of genetic variation? A) Single nucleotide polymorphisms B) Chromosomal mutations C) Environmental influences
C) Environmental influences
How do alleles contribute to genetic variation?
Alleles are different forms of a gene that can result in different traits among individuals.
True or False: All traits are influenced by both genetics and environment.
True
What is the Hardy-Weinberg principle?
The Hardy-Weinberg principle describes the genetic variation of a population that is not evolving.
Fill in the blank: The Hardy-Weinberg equation is p² + 2pq + q² = ________.
1
What does ‘p’ represent in the Hardy-Weinberg equation?
The frequency of the dominant allele.
What does ‘q’ represent in the Hardy-Weinberg equation?
The frequency of the recessive allele.
What is directional selection?
Directional selection is a type of natural selection that favors one extreme phenotype over others.
Give an example of stabilizing selection.
Stabilizing selection can be seen in human birth weights, where extreme weights are selected against.
What is disruptive selection?
Disruptive selection favors individuals at both extremes of the phenotypic range.
True or False: Genetic drift has a larger effect in small populations.
True
What is the founder effect?
The founder effect occurs when a small group of individuals establishes a new population, leading to reduced genetic diversity.
How can gene flow affect variation?
Gene flow introduces new alleles into a population, increasing genetic diversity.
What is a phenotype?
A phenotype is the observable physical or biochemical characteristics of an organism.
Fill in the blank: The observable traits of an organism are influenced by its ________ and environment.
genotype
What is the difference between a genotype and a phenotype?
A genotype is the genetic makeup of an organism, while a phenotype is the expression of that genetic makeup.
True or False: Environmental variation can lead to changes in genotype.
False
What are polygenic traits?
Polygenic traits are influenced by multiple genes, leading to a range of phenotypes.
Give an example of a polygenic trait.
Human height is an example of a polygenic trait.
What is a phenotype ratio?
The phenotype ratio is the relative frequency of different phenotypes in a population.
Fill in the blank: The term ________ refers to the genetic makeup of an individual.
genotype
What is the purpose of the AQA Biology A-Level curriculum regarding variations?
To understand the mechanisms and significance of variation in living organisms.
What is a genetic marker?
A genetic marker is a specific DNA sequence that can be used to identify individuals or species.
True or False: All individuals in a population are genetically identical.
False
What is the impact of selective breeding on variation?
Selective breeding reduces genetic variation by favoring specific traits.
What is a clone?
A clone is an organism that is genetically identical to another organism.
Fill in the blank: The study of heredity is known as ________.
genetics
What does the term ‘adaptive radiation’ refer to?
Adaptive radiation refers to the rapid evolution of diversely adapted species from a common ancestor.
What is the role of the environment in natural selection?
The environment determines which traits are advantageous for survival and reproduction.
True or False: Genetic diversity is important for the survival of a species.
True
What is speciation?
Speciation is the process by which new species arise from existing species.
Fill in the blank: The ________ hypothesis explains how species evolve through gradual changes.
gradualism
What is the difference between allopatric and sympatric speciation?
Allopatric speciation occurs when populations are geographically isolated, while sympatric speciation occurs within the same geographic area.
What is a homologous structure?
A homologous structure is an anatomical feature that is similar in different species due to shared ancestry.
Fill in the blank: Darwin’s theory of evolution is based on the concept of ________ selection.
natural
What does ‘survival of the fittest’ mean?
It refers to the idea that individuals with advantageous traits are more likely to survive and reproduce.
What is a phenotype frequency?
Phenotype frequency is the proportion of a particular phenotype in a population.
True or False: Phenotypic variation is solely due to genetic differences.
False
What is the significance of genetic diversity in ecosystems?
Genetic diversity enhances ecosystem resilience and adaptability to changing conditions.
Fill in the blank: The study of how traits are passed from parents to offspring is called ________.
inheritance
What is the function of the gene pool?
The gene pool contains all the alleles for every gene in a population.
What is the difference between a dominant and a recessive allele?
A dominant allele masks the effect of a recessive allele in heterozygous individuals.
True or False: A recessive trait can be expressed in a heterozygous individual.
False
What is the purpose of a Punnett square?
A Punnett square is used to predict the genotypes and phenotypes of offspring from genetic crosses.
Fill in the blank: The observable characteristics of an organism are determined by its ________.
genotype
What is a trait?
A trait is a specific characteristic or feature of an organism.
What is the role of chromosomes in genetic variation?
Chromosomes carry genes, and variations in chromosome number or structure can lead to genetic differences.
True or False: All individuals in a species have the same number of chromosomes.
False
What is a fitness landscape?
A fitness landscape is a representation of how different genotypes or phenotypes perform in terms of fitness.
Fill in the blank: The term ________ refers to the genetic contribution of an individual to the next generation.
fitness
What is the effect of inbreeding on genetic variation?
Inbreeding often reduces genetic variation and can increase the likelihood of genetic disorders.
True or False: Gene therapy can be used to introduce new genetic material into an organism.
True
What is a transgenic organism?
A transgenic organism is one that has been genetically modified to contain genes from another species.
Fill in the blank: The process of selecting organisms with desirable traits for breeding is called ________ breeding.
selective
What is the significance of the Galápagos Islands in the study of variation?
The Galápagos Islands provided key evidence for Darwin’s theory of evolution due to the unique species found there.
True or False: Artificial selection is the same as natural selection.
False
What is the concept of adaptive traits?
Adaptive traits are characteristics that enhance an organism’s ability to survive and reproduce in its environment.
Fill in the blank: The ________ effect can lead to a loss of genetic variation in small populations.
bottleneck
What is the main focus of evolutionary biology?
The main focus of evolutionary biology is to study the processes that drive the evolution of species.
True or False: Variation is only important in evolutionary contexts.
False
