Virus Structure and Classification Quiz
71 Questions
17 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the shape of the tobacco mosaic virus?

  • Spherical
  • Polyhedral
  • Helical (correct)
  • Complex

What type of virus specifically infects bacteria?

  • Bacteriophage (correct)
  • Influenza virus
  • Ebola virus
  • Adenovirus

Which of the following is a proposed origin theory of viruses?

  • Viruses evolved from larger mammals
  • Produced from fragments of genetic material of living organisms (correct)
  • Viruses were created in laboratory settings
  • Viruses are a byproduct of cellular respiration

Which virus is classified as having a complex shape?

<p>Bacteriophage (D)</p> Signup and view all the answers

How large are most viruses in diameter?

<p>Less than 0.1 micrometer (A)</p> Signup and view all the answers

What is the ratio of phenotypes expected when crossing two fully heterozygous individuals for two traits?

<p>9:3:3:1 (D)</p> Signup and view all the answers

Which of the following describes the Law of Independent Assortment?

<p>Genes located on separate chromosomes are inherited independently. (D)</p> Signup and view all the answers

In incomplete dominance, what phenotype is produced from a red flower crossed with a white flower?

<p>Pink flower (C)</p> Signup and view all the answers

What characterizes codominance in genetic inheritance?

<p>Both alleles are expressed equally in the phenotype. (A)</p> Signup and view all the answers

Which of the following is an example of a polygenic trait?

<p>Eye color (C)</p> Signup and view all the answers

What is the primary reason sex-linked traits are more common in males than in females?

<p>Females have two X chromosomes providing a backup. (C)</p> Signup and view all the answers

Which statement is true regarding non-Mendelian genetics?

<p>They incorporate concepts such as multiple alleles and codominance. (B)</p> Signup and view all the answers

What is a characteristic of sex-linked recessive traits?

<p>They can be easily observed in males only. (C)</p> Signup and view all the answers

Which of the following best explains the concept of biological diversity?

<p>The variety of living organisms on Earth. (A)</p> Signup and view all the answers

How does the Principle of Segregation contribute to genetic variation?

<p>Pairs of alleles segregate during gamete formation. (B)</p> Signup and view all the answers

What is the primary purpose of taxonomy in biology?

<p>To classify organisms and assign them names (B)</p> Signup and view all the answers

How many levels of classification did Linnaeus originally establish?

<p>7 (B)</p> Signup and view all the answers

Which of the following correctly describes a homologous structure?

<p>Structures that appear similar due to common ancestry (A)</p> Signup and view all the answers

Which of the following domains includes multicellular organisms?

<p>Eukarya (B)</p> Signup and view all the answers

What is the correct format for writing a scientific name in binomial nomenclature?

<p>Genus is capitalized, species lowercase, both italicized (A)</p> Signup and view all the answers

Which statement best defines natural selection?

<p>The selective survival of organisms based on favorable traits (D)</p> Signup and view all the answers

Which type of structure is a vestigial structure?

<p>A structure reduced in size from previous ancestors (C)</p> Signup and view all the answers

What was one of the main problems with Aristotle's classification system?

<p>It mistakenly grouped unrelated organisms together (C)</p> Signup and view all the answers

Which evidence is NOT considered by modern taxonomy when classifying organisms?

<p>Common names in local languages (A)</p> Signup and view all the answers

What do phylogenetic trees illustrate?

<p>The evolutionary relationships among groups of organisms (C)</p> Signup and view all the answers

Which structure's function is an example of an analogous structure?

<p>The wing of a bird and the wing of a butterfly (A)</p> Signup and view all the answers

Which of the following classifications is the broadest?

<p>Domain (D)</p> Signup and view all the answers

Which of the following is true about the organisms classified under the same genus?

<p>They share similar anatomical features. (D)</p> Signup and view all the answers

What is the significance of biochemistry in modern taxonomy?

<p>It provides evidence of evolutionary relationships (C)</p> Signup and view all the answers

What occurs in an individual with monosomy?

<p>They have one chromosome instead of a pair. (D)</p> Signup and view all the answers

What results from trisomy 21?

<p>Down Syndrome. (B)</p> Signup and view all the answers

Which condition results from having an extra X chromosome?

<p>Klinefelter Syndrome. (C)</p> Signup and view all the answers

Which syndrome is characterized by a monosomy of the sex chromosomes?

<p>Turner Syndrome. (B)</p> Signup and view all the answers

What genetic principle explains that two factors control each inherited trait?

<p>Law of Segregation. (C)</p> Signup and view all the answers

What describes the physical appearance resulting from an organism's genotype?

<p>Phenotype. (C)</p> Signup and view all the answers

In Mendel's experiments, what was the term for the first generation of offspring resulting from a genetic cross?

<p>F1 Generation. (B)</p> Signup and view all the answers

Which of the following best defines a dominant allele?

<p>An allele that blocks the expression of another allele. (B)</p> Signup and view all the answers

What occurs during prophase 1 of meiosis that can lead to chromosomal structural rearrangements?

<p>Crossing over between homologous chromosomes. (B)</p> Signup and view all the answers

What is the typical chromosomal composition of Klinefelter Syndrome?

<p>47, XXY. (D)</p> Signup and view all the answers

What type of genetic cross involves two organisms differing by a single trait?

<p>Monohybrid Cross. (D)</p> Signup and view all the answers

What is the cause of most miscarriages during early pregnancy?

<p>Chromosomal abnormalities. (B)</p> Signup and view all the answers

What is the role of amniocentesis in prenatal testing?

<p>To definitively diagnose chromosomal abnormalities. (D)</p> Signup and view all the answers

Which of the following statements is true about Triple X Syndrome?

<p>It involves an extra X chromosome in females. (B)</p> Signup and view all the answers

What do fossils primarily provide evidence for in the study of evolution?

<p>The history of life on Earth (D)</p> Signup and view all the answers

How do scientists determine the absolute age of fossils?

<p>Through radioactive dating (C)</p> Signup and view all the answers

Which of the following statements best describes homologous structures?

<p>They suggest a common ancestor among different species. (B)</p> Signup and view all the answers

What is the significance of transitional fossils?

<p>They demonstrate features between ancient ancestors and their descendants. (C)</p> Signup and view all the answers

Which process describes two or more related species becoming dissimilar through evolution?

<p>Divergent evolution (A)</p> Signup and view all the answers

In the context of biogeography, what did Darwin conclude about species on different continents?

<p>They evolved independently under the same environmental pressures. (D)</p> Signup and view all the answers

What is an example of a vestigial organ?

<p>The wisdom teeth in humans (D)</p> Signup and view all the answers

Which statement accurately describes analogous structures?

<p>They share a common function but are structurally different. (B)</p> Signup and view all the answers

What is the role of cytochrome C in evolutionary biology?

<p>As a protein for cellular respiration (A)</p> Signup and view all the answers

What is comparative anatomy primarily used to study?

<p>The structure and function similarities among organisms (C)</p> Signup and view all the answers

What is the basic building block of carbohydrates?

<p>Monosaccharides (C)</p> Signup and view all the answers

What distinguishes macronutrients from micronutrients?

<p>Macronutrients are consumed in larger amounts. (C)</p> Signup and view all the answers

What is the purpose of digestion in living organisms?

<p>To break down food into smaller molecules for energy (C)</p> Signup and view all the answers

What type of evolution occurs when unrelated species adapt to similar environments and develop similar features?

<p>Convergent evolution (C)</p> Signup and view all the answers

What is a characteristic of scientific theory?

<p>It is supported by extensive evidence. (A), It does not conflict with scientific findings. (B)</p> Signup and view all the answers

What does the Theory of Evolution suggest about modern species?

<p>They are the result of changes in heritable information. (A)</p> Signup and view all the answers

Which of the following concepts is aligned with gradualism in geology?

<p>Earth changes occur through long-term slow processes. (B)</p> Signup and view all the answers

What was Lamarck's theory regarding acquired characteristics?

<p>Acquired traits can be passed to offspring. (C)</p> Signup and view all the answers

Which of the following is an example of evidence for evolution?

<p>Fossils showing different species over time. (B)</p> Signup and view all the answers

Which observation led Darwin to propose his theory of natural selection?

<p>Species exhibited variation in different habitats. (A)</p> Signup and view all the answers

What do fossils and rock strata demonstrate in relation to evolution?

<p>Different species can exist at different times. (C)</p> Signup and view all the answers

What aspect of naturalism influenced Darwin's work during the age of imperialism?

<p>Naturalists gathered data under surveying missions. (D)</p> Signup and view all the answers

How did Charles Lyell influence the perspective on Earth's age?

<p>Through geological surveys supporting uniformitarianism. (D)</p> Signup and view all the answers

What was one of Darwin's notable observations during his voyage on the HMS Beagle?

<p>Some isolated regions had unique species not found elsewhere. (A)</p> Signup and view all the answers

What is transmutation in the context of early evolutionary ideas?

<p>Species changing due to environmental factors. (A)</p> Signup and view all the answers

What influenced Darwin’s understanding of species variability?

<p>The observation of similar traits in related animals in different habitats. (B)</p> Signup and view all the answers

What is the significance of Darwin's finches in his study of evolution?

<p>They varied in beak shapes across different islands. (C)</p> Signup and view all the answers

What is uniformitarianism in geology?

<p>The idea that current processes have shaped the earth over time. (D)</p> Signup and view all the answers

Flashcards

What are viruses and what are their characteristics?

Viruses are microscopic particles that need a host cell to reproduce. They are smaller than 0.1 micrometers, meaning 5000 flu viruses could fit on a pinhead. Viruses come in various shapes: helical (like a helix, e.g., tobacco mosaic virus), polyhedral (diamond-shaped, e.g., adenoviruses), spherical (round, e.g., coronavirus), or complex (like a robot, e.g., bacteriophages).

What are bacteriophages?

Bacteriophages are viruses that specifically infect and destroy bacteria. They are distinct from other viruses due to their unique, 'robot-like' shape with head and tail regions. They are the most abundant biological agents on Earth, outnumbering nearly all other organisms.

What are the theories on the origin of viruses?

The origin of viruses is still debated, with several theories on their evolution. Scientists believe they might have emerged from: (1) parasitic organisms that lost their ability to reproduce independently, (2) fragments of genetic material from existing organisms, or (3) virus-like particles that predate the first cells.

What is the lytic cycle?

The lytic cycle is a rapid viral reproduction process where a virus infects a host cell, replicates itself, and bursts the cell, releasing new viruses.  This process leads to immediate destruction of the host cell.

Signup and view all the flashcards

What is the lysogenic cycle?

The lysogenic cycle is a slower viral reproduction process where a viral genome integrates into the host cell's DNA without immediately replicating. The virus remains dormant until triggered, leading to a later burst of viral production.

Signup and view all the flashcards

Natural Selection

The process by which organisms better adapted to their environment tend to survive and reproduce more successfully.

Signup and view all the flashcards

Taxonomy

The scientific study of classifying organisms and assigning them names.

Signup and view all the flashcards

Aristotle's Classification System

The early system of classification developed by Aristotle, which divided organisms into plants and animals based on their general characteristics.

Signup and view all the flashcards

Binomial Nomenclature

A two-part naming system used to give each species a unique scientific name.

Signup and view all the flashcards

Domain

The broadest taxonomic category, above the kingdom level.

Signup and view all the flashcards

Species

The most specific taxonomic category, containing only one type of organism.

Signup and view all the flashcards

Phylogeny

The evolutionary history of an organism.

Signup and view all the flashcards

Phylogenetic Tree

A diagram that shows the evolutionary relationships between different groups of organisms.

Signup and view all the flashcards

Morphology

The study of the physical structures of organisms.

Signup and view all the flashcards

Homologous Structures

Structures in different species that are similar because of common ancestry.

Signup and view all the flashcards

Analogous Structures

Structures in different species that are similar in function, but not in structure.

Signup and view all the flashcards

Vestigial Structures

Structures that are reduced in size and seem to be leftover from a previous ancestor.

Signup and view all the flashcards

Homologous Structures

Structures that are similar in function and structure due to shared ancestry.

Signup and view all the flashcards

Analogous Structures*

Structures that are similar in function, but have different underlying structures, and are not due to shared ancestry.

Signup and view all the flashcards

Vestigial Structures*

A structure that has lost its original function, often reduced in size, and provides evidence of evolutionary history.

Signup and view all the flashcards

Principle of Segregation

A pair of alleles separate during meiosis, so each gamete receives only one allele from the pair.

Signup and view all the flashcards

Dihybrid Cross

A cross between two individuals differing in two traits.

Signup and view all the flashcards

Law of Independent Assortment

Genes on separate chromosomes are inherited independently.

Signup and view all the flashcards

Dihybrid Cross Ratio

The offspring of a dihybrid cross with two heterozygous parents display a phenotypic ratio of 9:3:3:1.

Signup and view all the flashcards

Incomplete Dominance

A pattern of inheritance where the heterozygote exhibits a phenotype that is a blend of the two homozygous phenotypes.

Signup and view all the flashcards

Codominance

A pattern of inheritance where both alleles are expressed equally in the heterozygote.

Signup and view all the flashcards

Polygenic Traits

Traits controlled by multiple genes, creating a range of phenotypes.

Signup and view all the flashcards

Sex-Linked Traits

Genes located on sex chromosomes (X or Y) that determine sex-linked traits.

Signup and view all the flashcards

Hemophilia

A genetic disorder linked to the X chromosome, usually affecting males more often due to their single X chromosome.

Signup and view all the flashcards

Evolution

The process of change in organisms over time, leading to the diversity of life on Earth.

Signup and view all the flashcards

Aneuploidy

An abnormal number of chromosomes.

Signup and view all the flashcards

Monosomy

Condition where an individual has only one chromosome instead of a homologous pair.

Signup and view all the flashcards

Polysomy

Condition where an individual has three or more of a specific chromosome.

Signup and view all the flashcards

Down Syndrome

Condition where an individual has three copies of chromosome 21.

Signup and view all the flashcards

Klinefelter Syndrome

Condition where an individual has an extra X chromosome (47, XXY).

Signup and view all the flashcards

Triple X Syndrome

Condition where an individual has an extra X chromosome (47, XXX).

Signup and view all the flashcards

Turner Syndrome

Condition where an individual has only one X chromosome (45, XO).

Signup and view all the flashcards

Chromosomal Structural Rearrangements

Structural rearrangements in chromosomes. These include partial duplications, deletions, inversions, and translocations.

Signup and view all the flashcards

Heredity

Passing of traits from parent to offspring.

Signup and view all the flashcards

Self pollination

When pollen from one plant lands on the pistil of the same plant.

Signup and view all the flashcards

Cross-pollination

When pollen from one plant lands on the pistil of a different plant.

Signup and view all the flashcards

True breeding

When a plant self pollinates, it always produces offspring with traits the same as the parent.

Signup and view all the flashcards

Alleles

Different forms of a gene.

Signup and view all the flashcards

Dominant Trait

An allele that blocks another allele.

Signup and view all the flashcards

Recessive Trait

An allele that is masked by a dominant allele.

Signup and view all the flashcards

Scientific Theory

In the context of natural science, a scientific theory is a well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experimentation.

Signup and view all the flashcards

Evolutionary Theory

The collection of scientific facts, observations, and hypotheses that attempt to explain the diversity of life on Earth. This theory is supported by a wealth of evidence from multiple fields of science and explains how species have changed and diversified throughout history.

Signup and view all the flashcards

What is a scientific theory?

A theory is a well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experimentation. It's supported by a lot of evidence and doesn't conflict with existing experimental results.

Signup and view all the flashcards

What is a scientific law?

A law is a statement that describes an observed pattern or relationship in nature. It's a concise and universal statement that summarizes a pattern, while a theory explains why a phenomenon occurs.

Signup and view all the flashcards

Theory of Evolution

The theory of evolution explains how species change over time. It suggests that modern species are the result of changes to heritable information (DNA) passed from generation to generation, and that all life on Earth shares a common ancestor.

Signup and view all the flashcards

Fixed or Immutable Species

The belief that species were created by a divine being and remained unchanged throughout history. This view was prevalent before Darwin's theories.

Signup and view all the flashcards

The Earth is Young

The early belief that the Earth is very young, less than 10,000 years old, and that its features were relatively unchanging.

Signup and view all the flashcards

Transmutation

A term used in the early 19th century to describe the idea that species could change or transform over time. This was an early attempt to explain the diversity of life.

Signup and view all the flashcards

Lamarck's Theory of Inheritance

A hypothesis proposed by Jean-Baptiste Lamarck that suggested that organisms could acquire traits during their lifetime and pass those traits on to their offspring. For example, the long neck of a giraffe was thought to have been acquired by generations of giraffes stretching to reach higher branches.

Signup and view all the flashcards

Catastrophism

The theory that the Earth's features were formed by sudden, catastrophic events like volcanoes, floods, or earthquakes. These events were thought to be responsible for mass extinctions and the formation of landforms.

Signup and view all the flashcards

Gradualism

The theory that the Earth's features were formed by gradual processes like erosion, sedimentation, and volcanic activity. These processes occur over long periods of time.

Signup and view all the flashcards

Uniformitarianism

The theory that the Earth's features were formed by processes that are still ongoing today. These processes, acting over millions of years, have shaped the Earth's surface.

Signup and view all the flashcards

Fossils and Strata

Fossils are the preserved remains or traces of ancient organisms. They provide evidence for past life, showing that organisms have changed over time.

Signup and view all the flashcards

Darwin's Voyage on the HMS Beagle

Darwin's voyage on the HMS Beagle was a pivotal moment in his development of the theory of evolution. He observed the immense diversity of life across the globe, noting similarities and differences between species in different regions.

Signup and view all the flashcards

Species Variability

Darwin noticed that species varied across the globe, with some regions containing unique organisms not found anywhere else. He also observed that species inhabiting similar habitats in different parts of the world shared similar features.

Signup and view all the flashcards

Environmental Influence on Traits

A trait that is beneficial in one environment might be useless or even harmful in another.

Signup and view all the flashcards

Fossil Record

The study of fossils provides the most direct evidence of evolution.

Signup and view all the flashcards

Fossils as a Record

Fossils are remnants of organisms from the past, offering a record of life on Earth.

Signup and view all the flashcards

Extinct Organisms

Many fossils represent organisms that no longer exist on Earth, often resembling current species.

Signup and view all the flashcards

Evolutionary Changes

Fossils demonstrate that organisms from the past differed from present-day organisms.

Signup and view all the flashcards

Relative Age

The relative age of a fossil refers to its age compared to other objects.

Signup and view all the flashcards

Strata and Relative Age

Scientists determine the relative age of fossils by their position in layers of rock, called strata.

Signup and view all the flashcards

Absolute Age

The absolute age of a fossil is its actual age in years.

Signup and view all the flashcards

Radioactive Dating

Radioactive dating uses the decay of radioactive isotopes to determine a fossil's age.

Signup and view all the flashcards

Transitional Fossils

Fossils with characteristics between ancient ancestors and their descendants, providing evidence of evolutionary transitions.

Signup and view all the flashcards

Archaeopteryx

Archaeopteryx is a famous transitional fossil with features of both reptiles and birds, supporting the theory of bird evolution from reptiles.

Signup and view all the flashcards

Fossil Limitations

Fossils primarily preserve hard tissues, limiting our knowledge of soft tissues and behaviors of past organisms.

Signup and view all the flashcards

Biogeography

The study of the distribution of organisms across the globe.

Signup and view all the flashcards

Divergent Evolution

The process of two or more related species becoming increasingly dissimilar through evolution.

Signup and view all the flashcards

Convergent Evolution

The process of two or more unrelated species developing similar features due to adapting to similar environments.

Signup and view all the flashcards

Study Notes

Biology 11: Unit 1 - Classification of Living Things

  • Biodiversity is the variety of life on Earth, encompassing all living things, whether multicellular or unicellular. A system of organization is needed to classify these living things.
  • Taxonomy is the classification system for living things.
  • Biological species are groups of organisms that can interbreed and produce fertile offspring. Members of the same species can interbreed, hence a labrador and a poodle can produce a fertile offspring called a labradoodle.
  • Zorses (horse + zebra hybrids) are infertile, indicating they are not the same species.
  • Genetic diversity refers to the variation of genes within a species,
  • Species diversity measures the number of each species and variation in a particular ecosystem.
  • Ecological diversity describes the variety of biological communities in terrestrial and aquatic ecosystems.

Three Levels of Biodiversity

  • Genetic diversity: The variety of genes within a species.
  • Species diversity: The number of different species present in an ecosystem.
  • Ecological diversity: The variety of biological communities.
  • Biotic and abiotic factors influence ecological diversity.

Classification of Living Things (Taxonomy)

  • Scientists group and classify organisms to organize the natural world.
  • Advances in technology improve classification systems.
  • Darwin's theory of evolution explains the modification and diversification of species over time.

Darwin's Theory of Evolution

  • Organisms produce more offspring than can survive.
  • Limited resources (food, water, shelter) lead to competition.
  • Individuals best adapted to their environments survive and reproduce.
  • Traits of the best adapted are passed on, leading to evolution.

Early Attempts of Classification

  • Aristotle classified organisms over 2,000 years ago into two main groups: animals and plants.
  • Later classifications expanded on this, recognizing different kingdoms, phylia, and other categories.
  • Problems arose with the use of common names as organisms were not always related by lineage.

Modern Taxonomy (Phylogeny)

  • Phylogeny considers the evolutionary history of an organism.
  • Modern taxonomists use a variety of data including morphology (body structure), cellular organization, evolutionary relationships, and genetic similarities to determine evolutionary relationships and relationships amongst species.
  • Phylogenetic trees illustrate evolutionary relationships among organisms.
  • Traditonally, morphology, structure, and cellular organization, embryological and biochemical similarities are all used to classify organisms.
  • Using more data (including molecular data), modern classification better represents evolutionary relationships amongst species.

Structure Types

  • Homologous Structures: similar structures in different species due to shared ancestry. (e.g. the bones in the arm of a human, cat, horse etc)
  • Analogous Structures: similar functions, different structures, (e.g. wings of a bird and wings of a bat).
  • Vestigial Structures: reduced structures with no apparent function in the current organism but were functional in the organism's ancestors. (e.g. the appendix in humans or whale hip bones).

Biochemical Similarities and Genetic Similarities

  • Comparing chemical compounds and DNA sequences helps assess relationships between organisms.
  • More similar the DNA, more closely species are related.

Cladistics

  • A method of classifying organisms based on evolutionary innovations (shared characteristics).
  • Creates a cladogram.
  • Organisms that share a common ancestor are in a clade and are more closely related.
  • The 'out-group' serves as a basis of comparison in a cladogram.

Classification of Living Things (Lesson 3): Domains

  • Domains are the highest taxonomic levels, including Bacteria, Archaea, and Eukarya.
  • Bacteria and Archaea are prokaryotic (no nucleus or other membrane enclosed organelles).
  • Eukaryotes, including Protista, Plantae, Fungi, and Animalia, are eukaryotic (with a nucleus).
  • Characteristics such as cell type, cell wall composition, and methods of feeding are used to group organisms.

Characteristics of Life

  • Movement
  • Respiration
  • Sensitivity
  • Growth
  • Reproduction
  • Excretion

Viruses

  • Viruses are not considered living organisms because they cannot perform any life processes on their own, requiring a host cell.
  • A virus is composed of a protein capsid and genetic material (DNA or RNA)

Viral Replication and Transmission

  • Lysogenic cycle: genetic material from the virus is incorporated into the host cellular DNA (genome).
  • Lytic cycle: viral genetic material replicates itself within the host cell and destroys the cell.

Genetic Material (DNA) and Traits

  • Traits are characteristics of an organism.
  • Hereditary refers to traits being passed down from parents.
  • Genetic information is stored in DNA.
  • Each gene codes for proteins, which create traits.

DNA Structure

  • DNA is a molecule made of four nitrogenous bases.
  • The bases (A,T,C,G) have specific pairing which forms the DNA structure
  • Pairs to create double helix.

The Cell Cycle

  • Interphase: The longest phase in the cell cycle that is divided into three subphases: G1, S, and G2. Growth, Synthesis, and Growth.
  • Mitosis (M phase) is a period of cell division.

Mitosis

  • The process where one 'parent cell' divides into two identical 'daughter cells'.
  • PMAT stages: Prophase, Metaphase, Anaphase and Telophase, ensuring genetic continuity.
  • DNA replication happens before mitosis and is responsible for creating an identical copy of DNA.

Mitosis Errors

  • Errors in DNA replication and division can result in mutations or variations in the genomic makeup of the organism.
  • Mutations are changes in DNA sequence and can occur spontaneously (errors in the replication or division process) or be caused by mutagens (external factors).
  • Mutations are important for studying inheritance and how genes are altered.

Meiosis

  • Meiosis is a specialized cell division process that occurs in germ cells to produce gametes (sex cells).
  • Meiotic division creates four non-identical gamete cells with half the number of chromosomes of the parent cell.

Gametogenesis

  • The process of producing gametes or reproductive cells, different for males (spermatogenesis) and females (oogenesis).
  • In spermatogenesis, a diploid germ cell produces four identical haploid sperm cells.
  • Polar bodies are produced during oogenesis to maintain the correct number of chromosomes in the mature egg cell.

Nondisjunction

  • Nondisjunction is an error that occurs during meiosis where homologous chromosomes or sister chromatids fail to separate.
  • Nondisjunction leads to gametes with an abnormal number of chromosomes and can cause genetic disorders with physical and/or mental abnormalities.
  • Nondisjunction is more common in females than males as the age of the mother impacts the frequency of the event.

Prenatal Testing

  • Methods of detecting genetic abnormalities in the fetus before birth, including screening tests (like eFTS) and diagnostic tests (like amniocentesis) to identify genetic abnormalities - such as trisomy 21.

Sources of variation

  • Different forms of a gene or allele, inheritance, independent assortment, and random chance.

Mendelian Genetics

  • Laws of Inheritance
  1. Principle of dominance: A dominant allele will mask the expression of a recessive allele in the heterozygous condition.
  2. Principle of Segregation: When gametes are formed, each allele pair segregates randomly.

Beyond Mendelian Genetics

  • Incomplete dominance: The heterozygous phenotype results in a phenotype that is intermediate between the homozygous phenotypes.
  • Codominance: Both alleles express themselves in the phenotype.
  • Polygenic traits: Traits effected by more than one gene.
  • Sex-linked traits: traits on the sex chromosomes.

Evolution

  • Evolution is the process of gradual change over time in the genetic makeup of populations.
  • Organisms may acquire certain traits to improve their fitness and ability to survive and reproduce in their environments.
  • Modern theory is supported by many lines of evidence.
  • Organisms change and some of those changes result in traits that enable them to survive and reproduce better.

Evidence for Evolution

  • Fossil record: Ordered sequence in strata representing the history of life on Earth.
  • Geographic distribution of species: Similar organisms found in similar environments on different continents suggest common descent.
  • Homologous body structures: Similar underlying anatomical structures among diverse species.
  • Vestigial structures: Rudimentary structures with little or no apparent function in modern organisms. Analogous structures in modern organisms fill a similar function but have different origins.
  • Comparative embryology: Similarity in embryonic development.
  • Molecular biology: Similarity in DNA and protein sequences.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

Biology Exam Review - Classification of Living Things PDF

Description

Test your knowledge about the structure and classification of viruses. This quiz covers topics such as the shape of the tobacco mosaic virus, types of viruses that infect bacteria, and various theories about the origins of viruses. Challenge yourself with these thought-provoking questions!

More Like This

Use Quizgecko on...
Browser
Open
Browser
Browser