BIOLOGY Focused on Week 2-3

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Questions and Answers

Which of the following is an example of an adaptation that has evolved in living organisms?

The size of a river

The shape of a bird’s beak (correct)

The length of a fish's tail

The temperature of the ocean

What type of structure is formed from similar anatomical features inherited from a common ancestor?

Convergent Structure

Diverging Structure

Homologous Structure (correct)

Analogous Structure

What is the primary mechanism that introduces new inheritable variation in a population?

Genetic Drift

Natural Selection

Mutations (correct)

Gene Flow

Which statement accurately describes genetic drift?

It causes changes in allele frequency due to random chance in small populations. Signup and view all the answers

Which factor has contributed to the distinct species found in Australia?

Geographic isolation for about 50 million years Signup and view all the answers

In terms of biochemical evidence, which two species share a high degree of similarity in DNA sequences?

Humans and chimpanzees Signup and view all the answers

What is the role of alleles in genetics?

They are variations in a gene affecting a specific trait. Signup and view all the answers

Which of the following is NOT a characteristic of mutations?

They provide a survival advantage in every case. Signup and view all the answers

What is the primary mechanism of evolution described in Darwin's theory?

Natural selection Signup and view all the answers

Which of the following describes a key concept of natural selection?

There is competition for limited resources. Signup and view all the answers

According to Darwin, what happens to favorable traits in a population over time?

They become more common through reproduction. Signup and view all the answers

Which scientist proposed the theory of inheritance of acquired characteristics?

Jean-Baptiste de Lamarck Signup and view all the answers

What was one of the key observations Darwin made during his voyage?

Beak size and shape varied among finches on different islands. Signup and view all the answers

What does 'descent with modification' imply?

Species evolve over time through inherited changes. Signup and view all the answers

Which statement is a significant difference between Lamarck's and Darwin's theories?

Darwin focused on natural selection rather than acquired traits. Signup and view all the answers

How does an organism's variation contribute to evolution?

Some variations enhance survival and reproductive success. Signup and view all the answers

What is the primary effect of gene flow on genetic variation?

Increases genetic variation Signup and view all the answers

Which of the following best describes the bottleneck effect?

A significant reduction in population size due to a disaster Signup and view all the answers

How does non-random mating affect genetic diversity in a population?

It generally decreases genetic diversity Signup and view all the answers

What defines microevolution?

Small-scale changes within a species Signup and view all the answers

Which of the following statements about cell theory is correct?

Cells are the basic unit of life and all living organisms are made of one or more cells Signup and view all the answers

What is the main outcome of natural selection in a population?

Survival of individuals with favorable traits Signup and view all the answers

Which phenomenon describes a new species arising from geographical isolation?

Speciation Signup and view all the answers

Which of the following describes the founders effect?

A small subgroup establishing a new population Signup and view all the answers

What feature distinguishes eukaryotic cells from prokaryotic cells?

Presence of membrane-enclosed organelles Signup and view all the answers

Which component of a cell regulates the entry and exit of substances?

Plasma membrane Signup and view all the answers

What is the role of the Golgi apparatus in a eukaryotic cell?

Modification and distribution of proteins Signup and view all the answers

How do the surface area and volume ratios of cells change as cell size increases?

Volume increases proportionately more than surface area Signup and view all the answers

Which structure serves as the site of protein synthesis within a cell?

Ribosomes Signup and view all the answers

What is the composition of ribosomal subunits?

Ribonucleic acid (RNA) and protein molecules Signup and view all the answers

Which of the following accurately describes the nucleus?

It stores DNA and contains the nucleolus Signup and view all the answers

What type of cells are structurally complex and possess membrane-bound organelles?

Eukaryotic cells Signup and view all the answers

What is the primary function of lysosomes in a cell?

Break down unwanted foreign substances and worn-out cell parts Signup and view all the answers

Which organelle is primarily involved in the packaging, storage, and distribution of molecules produced by the endoplasmic reticulum?

Golgi apparatus Signup and view all the answers

What structures are chloroplasts primarily involved in?

Photosynthesis Signup and view all the answers

Which type of fiber in the cytoskeleton is responsible for maintaining cell shape and enabling movement?

Actin filaments Signup and view all the answers

What is the main byproduct produced by peroxisomes during the breakdown of fatty acids?

Hydrogen peroxide (H2O2) Signup and view all the answers

What structural feature do both mitochondria and chloroplasts share?

Double membrane Signup and view all the answers

Which component of the cytoskeleton is the largest in diameter?

Microtubules Signup and view all the answers

Which of the following is NOT found in mitochondria?

Hydrolytic enzymes Signup and view all the answers

Study Notes

Week 2: Study of Life & Evolution of Life

Darwin initially believed species remained unchanged.
Darwin's voyage observed geological and biological diversity, noting variations in Galapagos finches.
Evolution is an evolved trait that benefits an organism's environment.
Natural Selection: Individual organisms show variations that are heritable and passed down. Organisms compete for resources.
Organisms produce more offspring than the environment can support.
Some individuals have traits that give them a better chance of survival and reproducing (survival of the fittest).
Beneficial traits increase in the population; the population adapts to its environment.
Darwin was influenced by Lamarck's theory of inheritance of acquired characteristics, where the environment drives inherited change.
Lamarck used the giraffe example, in which giraffes stretched their necks to reach higher leaves and passed the trait to offspring.

Theory of Evolution by Natural Selection

Darwin's theory predicts that a population of giraffes will have varied neck lengths.
Individuals with longer necks can reach more food, increasing their chances of survival and reproduction.

Evidence of Evolution

Fossils: Some fossils are transitional links between groups, demonstrating the characteristics of an ancestor and descendant.
Biogeography: Continents and oceans have shifted, leading to unique species in geographically isolated areas, like Australia, that have been isolated for 50 million years.
Anatomy: Similar characteristics in different species may indicate a shared ancestor (homologous structures). Structures with similar functions but different origins are analogous.
Biochemistry: High DNA similarity suggests a close evolutionary relationship between species like humans and chimpanzees.

Processes of Evolution

Evolution is the heritable change in traits in populations, through many generations.
Mutations: Changes in DNA are the source of new inheritable variations. They are random events that may be beneficial, harmful, or neutral to an organism's survival.
Gene Flow: Movement of alleles (forms of a gene) between populations, increasing variations. Migration of individuals or gametes (sex cells) to a new population leads to more genetic diversity.
Natural Selection: Individuals with favorable traits are more likely to survive and reproduce, passing down those traits to future generations. This leads to adaptations to the environment.
Genetic Drift: Random changes in allele frequencies in small populations can significantly alter the genetic makeup, impacting genetic diversity within a population due to chance events.

Natural Selection (continued)

Survival of the fittest leads to adaptations to the environment.
Populations with favorable adaptations are passed down to future generations.

Nonrandom Mating

Nonrandom mating occurs when individuals select mates based on specific traits. This can decrease diversity within a population.
Artificial selection is human-controlled breeding to increase frequency of desired traits, impacting traits in populations.

Microevolution

Variation within a species, such as different dog breeds, is an example of microevolution. Microevolution is change within a species over time.
Artificial selection driving changes over generations.

Macroevolution

The large-scale evolutionary process of species formation from one species into two species.

Week 3 - Cell Structure and Function

Cells are basic units of life, forming the structural and functional unit of any organism.
Cells have a plasma membrane, cytoplasm, and genetic material (DNA).
Cell theory: Cells are the basic units of all living organisms, all organisms are made of cells, and cells come from pre-existing cells.
Prokaryotic cells lack membrane-enclosed structures, while eukaryotic cells have them.
The plasma membrane regulates what enters and exits the cell and is composed of polar (hydrophilic) heads and nonpolar (hydrophobic tails).

Surface Area-to-Volume Ratio

Smaller cells have a larger surface area to volume ratio, allowing easier exchange of materials with their surroundings.
As cells increase in size, surface area becomes less relative to volume, so materials must be more efficiently transported.

Eukaryotes

Eukaryotes, includes animals, plants, fungi, and protists.
They have a nucleus, membrane-bound organelles, and are complex compared to prokaryotes.

Cell Organelles (Examples)

Nucleus: Stores DNA.
Ribosomes: Synthesize proteins.
Golgi apparatus: Modifies, sorts, and packages proteins and lipids.
Endoplasmic reticulum: Involved in protein synthesis and lipid production.
Mitochondria: Site of cellular respiration, producing energy.

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Description

Dive into the core concepts of evolution and natural selection in this quiz. Explore Darwin's observations, the impact of variations and traits in survival, and the influences of Lamarck's theory. Test your understanding of how species adapt to their environments over time.