Biology and physics (year 10) Flashcards
What is evolution, and how is it defined in scientific terms?
Evolution is the gradual change in the physical characteristics of living organisms over many generations, often due to natural selection.
What is biogeography, and how does it contribute to the evidence of evolution?
Biogeography is the study of the past and present distribution of living organisms, and it helps provide evidence for the common ancestry of species.
What is comparative anatomy, and how does it support the theory of evolution?
Comparative anatomy involves comparing features of different species to find evidence of a common ancestor, providing support for evolutionary relationships.
What are homologous structures, and how do they relate to evolutionary evidence?
Homologous structures are parts of organisms that show evidence of a common ancestor, reinforcing the idea of shared ancestry among species.
What are vestigial structures, and how do they provide evidence for evolution?
Vestigial structures are parts of an organism that have lost some or all of their original function, indicating evolutionary changes over time.
What are some examples of vestigial structures in humans?
Examples include wisdom teeth, the appendix, nipples on men, and tonsils, which have limited or no useful function in modern humans.
What is comparative embryology, and how does it contribute to the evidence of evolution?
Comparative embryology involves studying the development of embryos in different species to identify shared traits and common ancestry.
How does the presence of branchial arches in embryos relate to evidence for evolution?
Branchial arches in embryos of different species suggest shared ancestry and common features, supporting evolutionary relationships.
What is genetic evidence, and how does it provide support for the theory of evolution?
Genetic evidence involves comparing DNA and protein sequences to reveal similarities and differences among species, reinforcing the concept of common ancestry.
What is the Human Genome Project, and how does it contribute to genetic evidence for evolution?
The Human Genome Project mapped the DNA of humans, enabling the comparison of DNA from different species to identify genetic similarities, supporting the concept of a common ancestor.
What are proteins, and how are they related to genetic evidence for evolution?
Proteins are molecules made of amino acids and play vital roles in living organisms. Amino acid sequences in proteins can be analyzed to assess the relatedness of species.
How does comparing amino acid sequences in proteins help determine species relatedness?
Small differences in amino acid sequences suggest closely related species, while large differences indicate that common ancestors lived long ago.
What is cytochrome C, and how does it contribute to genetic evidence for evolution?
Cytochrome C is a protein involved in aerobic respiration and is found in many animals and plants. It provides a basis for analyzing genetic similarities. The fewer differences in cytochrome C sequences between species, the more recently they shared a common ancestor, providing compelling evidence for the theory of evolution. The more differences signify a more distant common ancestor, helping to establish the evolutionary relationships between various organisms and supporting the idea of species gradually changing over time. This molecular evidence adds a valuable layer of support to the broader body of evidence demonstrating evolutionary processes.
What is biogeography, and how does it contribute to the evidence of evolution?
Biogeography is the study of the past and present distribution of living organisms, and it offers evidence by comparing fossils from different continents to demonstrate species migration and common ancestry.
Can you provide an example of evidence for evolution from Australian marsupials?
Australian marsupials have common features with South American marsupials, suggesting they evolved from a common ancestor millions of years ago when the continents were connected.
How does the distribution of flightless birds (Ratites) provide evidence for evolution?
The distribution of flightless birds suggests that they originated from a common ancestor on Gondwana, and as continents drifted apart, different populations evolved on isolated southern continents.
What are fossils, and how do they contribute to the understanding of evolution?
Fossils are the remains, impressions, or traces of long-dead organisms, and they help reveal the history of life on Earth and how species have changed over time.
What is the fossil record, and what information does it provide?
The fossil record is a record of all fossils found on Earth, showing how organisms have evolved from simpler to more complex forms over geologic time.
How are fossils formed, and what conditions are necessary for their preservation?
Fossils are formed when organisms are quickly protected, buried in sediment, hardened, and gradually brought closer to the surface through geological processes.
What are the main types of fossils, and how do they differ?
The main types of fossils include original fossils, indirect or trace fossils, mould fossils, mineralized or cast fossils, mummified organisms, and carbon film fossils, each preserving organisms in various ways.
How does the fossil record support the theory of evolution?
The fossil record shows that older fossils represent simpler organisms, while younger fossils show more complex ones, providing evidence for the gradual evolution of life on Earth.
What are the two main methods for dating fossils, and how do they work?
Relative dating compares fossils to surrounding layers, while absolute dating uses radioactive minerals in rocks to calculate numerical ages.
What is half-life in the context of dating fossils?
Half-life is the time required for half of the atoms of a radioactive substance to become stable, which is used in absolute dating methods.
How does the geological time scale reveal the progression of complexity in living organisms?
The geological time scale shows that older fossils represent simpler organisms, while younger fossils exhibit more complex forms, supporting the theory of evolution.
What is natural selection, and how does it drive evolutionary changes?
Natural selection is the process where organisms better suited to their environment tend to survive, reproduce, and pass beneficial traits to the next generation.
Who is the scientist known for proposing natural selection and evolution in his book “The Origin of Species”?
Charles Darwin.
What are the five key elements of Darwin’s theory of natural selection?
The five key elements are overproduction, variation, competition, selection or adaptation, and speciation.
Who was Jean-Baptiste Lamarck, and what was his theory of evolution?
Lamarck believed in the inheritance of acquired traits, where organisms modified themselves during their lifetime, and these acquired traits were passed to offspring.
What did Charles Darwin discover about finches during his expedition to the Galapagos Islands?
Darwin discovered that finches on the Galapagos Islands had different beaks adapted to their specific food sources, providing evidence for natural selection.
How do mosquitoes develop resistance to pesticides, and what does this illustrate about natural selection?
Mosquitoes develop resistance to pesticides through natural selection favoring resistant individuals, reducing the effectiveness of pesticides.
How does the development of antibiotic-resistant bacteria illustrate natural selection?
Antibiotic-resistant bacteria evolve when antibiotics are overused, allowing resistant strains to survive and reproduce.
How is the concept of half-life used in the context of radioactive dating?
Half-life is a fundamental concept in radioactive dating that measures the time required for half of the atoms in a radioactive substance to become stable or decay. This concept is applied in radiometric dating methods, such as carbon dating or uranium-lead dating. By measuring the remaining amount of radioactive material in a sample and knowing the half-life of the radioactive isotope, scientists can calculate the age of the sample. For example, in carbon dating, the isotope carbon-14 decays with a known half-life, and by comparing the ratio of carbon-14 to carbon-12 in a sample, the age of organic materials can be determined. The shorter the remaining half-life, the more accurate the dating method is for relatively young materials, while longer half-lives are used for older specimens, providing a powerful tool for estimating the ages of fossils and rocks in the geological record.
How does the geological time scale reveal the progression of complexity in living organisms?
The geological time scale is a chronological framework that organizes Earth’s history into distinct time intervals. It shows that older fossils, found in lower rock layers, typically represent simpler life forms, such as single-celled organisms and simple invertebrates. In contrast, younger fossils, found in higher rock layers, exhibit more complex life forms, including vertebrates and eventually mammals and humans. This progressive increase in complexity observed in the fossil record aligns with the theory of evolution, indicating that life on Earth evolved gradually from simpler to more intricate forms over geological time. The geological time scale, by illustrating this pattern of increasing complexity, provides crucial evidence for the theory of evolution.
What is natural selection, and how does it drive evolutionary changes?
Natural selection, often referred to as “survival of the fittest,” is the process by which organisms better adapted to their environment tend to survive and reproduce more successfully. This leads to the passing on of beneficial traits to subsequent generations. Natural selection operates through several key principles:
- Overproduction: In any generation, there are more offspring produced than can survive, resulting in competition for limited resources.
- Variation: Individuals within a population display genetic variation, leading to differences in traits or characteristics.
- Competition: Individuals with more favorable traits are better equipped to compete for resources and survive in their environment.
- Selection/Adaptation: Those with advantageous traits are more likely to survive, reproduce, and pass on these traits to their offspring.
- Speciation: Over many generations, the advantageous traits become more common in the population, potentially leading to the emergence of new species.
Natural selection is a fundamental mechanism of evolution, explaining how species change and adapt to their surroundings over time. It helps shape the diversity of life on Earth by favoring traits that enhance an organism’s chances of survival and reproduction.
What are the five key elements of Darwin’s theory of natural selection?
Darwin’s theory of natural selection comprises five key elements:
- Overproduction: Organisms produce more offspring than can survive, leading to competition for resources.
- Variation: Individuals within a population exhibit genetic diversity, resulting in differences in traits.
- Competition: Individuals with more advantageous traits have a better chance of surviving and reproducing.
- Selection/Adaptation: Favorable traits become more prevalent in a population over time.
- Speciation: The accumulation of advantageous traits can eventually lead to the formation of new species.
These elements describe the fundamental principles that drive the process of natural selection.
Can you provide an example of natural selection in action in the animal kingdom?
One classic example of natural selection is the change in the color of peppered moths in response to industrial pollution during the 19th and 20th centuries in England. Prior to pollution, most peppered moths had pale coloration, which camouflaged them against lichen-covered tree trunks. However, as industrialization darkened the tree trunks with soot and pollution, darker moths became better camouflaged, making them less vulnerable to predation by birds. Over time, the frequency of dark-colored moths in the population increased as they had a survival advantage, demonstrating the process of natural selection.
What is antibiotic resistance, and how does it relate to natural selection?
Antibiotic resistance is the ability of bacteria to evolve and develop mechanisms to withstand the effects of antibiotics, rendering these drugs less effective in treating infections. The phenomenon of antibiotic resistance is a direct result of natural selection. Here’s how it works:
- Bacteria are exposed to antibiotics as a form of treatment.
- Within a bacterial population, there is genetic variation, and some bacteria may have inherent resistance to the antibiotic.
In the presence of antibiotics, only the bacteria with resistant traits survive, as they are not affected by the drug. - Over time, the surviving, antibiotic-resistant bacteria reproduce and pass on their resistant traits to their offspring.
- As a result, the population becomes increasingly dominated by antibiotic-resistant strains, and the effectiveness of antibiotics diminishes.
This process illustrates how natural selection operates on a rapid timescale, favoring those organisms with traits that enhance their survival and reproduction, even in the face of human intervention, such as the use of antibiotics.
Define adaptation.
A change in the structure or function of a species over a long time that makes it better suited to its environment.
What is a gene?
A unit of hereditary information passed from parents to offspring, composed of DNA.
Define genetic variation.
The differences in genes within individuals of a population.
How does genetic variation impact the survival of a population?
Genetic variation is essential for the continuation of life on Earth as it allows for adaptation to changing environments. It enables natural selection to produce populations that are well-suited to their surroundings. However, a lack of genetic diversity can make populations vulnerable to environmental changes, hindering their ability to adapt and survive.
What environmental factors can influence the survival of organisms?
Several environmental factors can affect the survival of organisms, including sunlight, temperature, wind, soil quality, pH, and water availability. Organisms typically thrive within specific temperature ranges and rely on factors like resource availability, mates, the presence of predators, and population density.
How do humans impact the survival of other species through their activities?
Human activities, such as habitat destruction, have a detrimental effect on the environment and can lead to the extinction of many species. Efforts in conservation management, including the creation of protected areas, reducing deforestation, sustainable resource use, and protection of vulnerable species, help mitigate the negative impact of human activities on the survival of other species.
define gamete
A sex cell, either an ovum (egg) or sperm.
What is menstruation?
The monthly discharge of blood and tissue from the lining of the uterus.
What is an ovum?
A female sex cell, also known as an egg. Ova contain genetic material and are the largest human cells, visible to the naked eye. An ovum is 0.12 mm in diameter.
What is semen?
A protective fluid that contains sperm.
