Podcast
Questions and Answers
Which type of variation gives rise to a smooth bell-shaped curve when plotted as a graph?
Which type of variation gives rise to a smooth bell-shaped curve when plotted as a graph?
Blood group is an example of continuous variation.
Blood group is an example of continuous variation.
False
Name one example of genetic variation in humans.
Name one example of genetic variation in humans.
Blood group or eye colour
Phenotypic variation can be genetic, caused entirely by ______ or environmental, caused entirely by the environment.
Phenotypic variation can be genetic, caused entirely by ______ or environmental, caused entirely by the environment.
Signup and view all the answers
Match the following types of variation with their characteristics:
Match the following types of variation with their characteristics:
Signup and view all the answers
What is the primary reason white shelled snails survive longer than their black or grey counterparts?
What is the primary reason white shelled snails survive longer than their black or grey counterparts?
Signup and view all the answers
The term 'survival of the fittest' refers to the ability of organisms to reproduce more successfully than others in their population.
The term 'survival of the fittest' refers to the ability of organisms to reproduce more successfully than others in their population.
Signup and view all the answers
What happens to the allele for white shells over generations in the snail population?
What happens to the allele for white shells over generations in the snail population?
Signup and view all the answers
In natural selection, variations in a population can arise from __________.
In natural selection, variations in a population can arise from __________.
Signup and view all the answers
Match the following concepts with their descriptions:
Match the following concepts with their descriptions:
Signup and view all the answers
What distinguishes continuous variation from discontinuous variation?
What distinguishes continuous variation from discontinuous variation?
Signup and view all the answers
Phenotypic variation can include traits that are influenced by both genetic and environmental factors.
Phenotypic variation can include traits that are influenced by both genetic and environmental factors.
Signup and view all the answers
Give two examples of characteristics that exhibit continuous variation.
Give two examples of characteristics that exhibit continuous variation.
Signup and view all the answers
In discontinuous variation, groups are categorized distinctly such as blood types A, B, AB, or ___ .
In discontinuous variation, groups are categorized distinctly such as blood types A, B, AB, or ___ .
Signup and view all the answers
Match the types of variation with their examples:
Match the types of variation with their examples:
Signup and view all the answers
What graph shape is typically produced by plotting continuous variation?
What graph shape is typically produced by plotting continuous variation?
Signup and view all the answers
Discontinuous variation can have many ‘in-between’ values.
Discontinuous variation can have many ‘in-between’ values.
Signup and view all the answers
Define genetic variation in your own words.
Define genetic variation in your own words.
Signup and view all the answers
What is one adaptation of xerophytes to minimize water loss?
What is one adaptation of xerophytes to minimize water loss?
Signup and view all the answers
Only large plants can survive in deserts.
Only large plants can survive in deserts.
Signup and view all the answers
Who put forward the theory of natural selection?
Who put forward the theory of natural selection?
Signup and view all the answers
The process where individuals with favorable traits are more likely to survive and reproduce is known as __________.
The process where individuals with favorable traits are more likely to survive and reproduce is known as __________.
Signup and view all the answers
Match the adaptations of xerophytes with their purposes:
Match the adaptations of xerophytes with their purposes:
Signup and view all the answers
What environmental condition do xerophytes primarily adapt to?
What environmental condition do xerophytes primarily adapt to?
Signup and view all the answers
Natural selection can lead to changes in the alleles of a population over time.
Natural selection can lead to changes in the alleles of a population over time.
Signup and view all the answers
What leads to competition among individuals in an environment?
What leads to competition among individuals in an environment?
Signup and view all the answers
What is the primary consequence of natural selection?
What is the primary consequence of natural selection?
Signup and view all the answers
Natural selection leads to a change in the characteristics of a population over time.
Natural selection leads to a change in the characteristics of a population over time.
Signup and view all the answers
What is defined as the change in adaptive features of a population over time due to natural selection?
What is defined as the change in adaptive features of a population over time due to natural selection?
Signup and view all the answers
The development of __________ resistance by bacteria is an example of adaptation by natural selection.
The development of __________ resistance by bacteria is an example of adaptation by natural selection.
Signup and view all the answers
Match the following components with their roles in natural selection:
Match the following components with their roles in natural selection:
Signup and view all the answers
If the environment changes, what might occur in terms of natural selection?
If the environment changes, what might occur in terms of natural selection?
Signup and view all the answers
Individuals with a survival advantage are less likely to breed.
Individuals with a survival advantage are less likely to breed.
Signup and view all the answers
What occurs over generations as a result of natural selection?
What occurs over generations as a result of natural selection?
Signup and view all the answers
What is the primary goal of selective breeding?
What is the primary goal of selective breeding?
Signup and view all the answers
Selective breeding involves choosing individuals with undesirable characteristics to breed together.
Selective breeding involves choosing individuals with undesirable characteristics to breed together.
Signup and view all the answers
Name one characteristic that is commonly selected for in domesticated animals through selective breeding.
Name one characteristic that is commonly selected for in domesticated animals through selective breeding.
Signup and view all the answers
An example of a plant that has been selectively bred in multiple ways is __________.
An example of a plant that has been selectively bred in multiple ways is __________.
Signup and view all the answers
Which of the following is NOT a benefit of selective breeding in crop plants?
Which of the following is NOT a benefit of selective breeding in crop plants?
Signup and view all the answers
All dog breeds today are descended from multiple distinct species.
All dog breeds today are descended from multiple distinct species.
Signup and view all the answers
What must occur over many generations in selective breeding to establish a new breed?
What must occur over many generations in selective breeding to establish a new breed?
Signup and view all the answers
Match the following characteristics with their corresponding outcome in selective breeding:
Match the following characteristics with their corresponding outcome in selective breeding:
Signup and view all the answers
Study Notes
Variation in Biology
- Variation is defined as differences between individuals of the same species.
- Phenotypic variation is the difference in features between individuals of the same species.
- Some of these differences are caused by differences in genes, which is genetic variation.
- Phenotypic variation can be divided into two types depending on how the measurements are grouped.
Types of Variation
- Continuous Variation: Many small degrees of difference in a characteristic, measured on a scale. Examples include height, mass, and finger length.
- Discontinuous Variation: Distinct differences in a characteristic, with no in-between values. Examples include blood groups (A, B, AB, O), sex (male or female), and tongue rolling ability.
- When plotted graphically, continuous variation shows a smooth bell curve, while discontinuous variation forms a step-like shape.
Genetic Variation
- Examples of genetic variation in humans include blood group and eye color.
Environmental Variation
- Characteristics are affected by factors such as climate, diet, culture, lifestyle, and accidents.
- Examples include scarring from an accident, weight gain from poor diet, and speaking a specific language based on where you grew up.
Genetic and Environmental Causes
- Discontinuous variation is usually caused by genetic variation alone.
- Continuous variation often results from a combination of genetic and environmental factors.
Mutations
- Mutations are random genetic changes to DNA.
- Most mutations have no effect on the phenotype.
- Occasionally, mutations lead to new alleles creating new phenotypes and may give an individual a survival advantage over other members of the species.
- Examples include changes in feather colors that could improve mating success.
- Mutations can be harmful to individuals, exemplified by sickle cell anemia.
- Mutations can be increased by exposure to ionizing radiation (e.g., X-rays, gamma rays) or certain chemicals.
Adaptive Features
- Adaptive features are inherited traits that increase an organism's fitness.
- Fitness is the probability of an organism surviving and reproducing in its environment.
- Plants have adapted leaves depending on their habitat.
Hydrophytes
- Plants adapted to extremely wet conditions.
- Common adaptations include large air spaces in leaves for flotation, small roots, and stomata mainly on the upper epidermis.
Xerophytes
- Plants adapted to extremely dry conditions.
- Common adaptations include a thick waxy cuticle, sunken stomata, rolled leaves with stomata on the inside, and extensive shallow roots.
- Plants in very dry conditions like deserts have small, needle-shaped leaves to minimize water loss.
Natural Selection
- Individuals with the most beneficial adaptive features are more likely to survive and reproduce.
- This leads to natural selection as only those individuals are capable of having offspring with similar traits.
- This is known as the concept of 'survival of the fittest'.
Artificial Selection
- Humans select individuals with desirable characteristics and breed them together.
- This process is repeated for successive generations to produce a 'new breed' with specific desired traits.
- Examples include dog breeds like pugs, and crop plants like cauliflower, broccoli, and kale all evolved from the same original plant.
Natural vs Artificial Selection
- Natural selection occurs naturally, leading to populations better adapted to their environment.
- Artificial selection is when humans intervene and control which traits are passed on to the next generation.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Explore the concepts of variation and natural selection in this quiz. You'll learn about continuous vs. discontinuous variation, examples of genetic variation, and how environmental factors can influence phenotypic traits. Test your knowledge on survival strategies and allele changes in populations.
