Biology Chapter 1: Cell Structure and Function Quiz

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Questions and Answers

What structure is NOT considered a basic feature of all cells?

Genetic material

Cell wall (correct)

Ribosomes

Plasma membrane

Which measurement unit is primarily used for measuring atoms?

Meter

Micrometer

Nanometer

Angstrom (correct)

Why is understanding cells important in biology?

Cells are fundamental to understanding human health. (correct)

Cells differentiate organisms from non-living things.

Cells exhibit identical structures across all species.

Cells are the smallest units of matter.

What is the function of ribosomes in cells?

To synthesize proteins Signup and view all the answers

What statement best describes the nature of cells in multicellular organisms?

Cells are similar but can serve different functions. Signup and view all the answers

What is the relationship between cell theory and evolution in biology?

Both cell theory and evolution explain the diversity of life. Signup and view all the answers

How do metabolic pathways contribute to cellular functions?

They convert energy into biochemical work. Signup and view all the answers

What is a common feature shared by all living cells?

Cells contain cytosol. Signup and view all the answers

What is the main mechanism behind Darwinian evolution?

Natural selection Signup and view all the answers

Which of the following statements is true according to Cell Theory?

Cells are the smallest self-reproducing unit of life. Signup and view all the answers

How does modern cell theory describe the origin of new cells?

New cells arise from existing cells. Signup and view all the answers

Which of the following best describes a characteristic of all living organisms?

All are made up of cells. Signup and view all the answers

In evolutionary biology, what does the phrase 'related by descent from a common ancestor' imply?

Species share a lineage traced back to a single ancestor. Signup and view all the answers

What role does energy flow play within cells according to modern cell theory?

It contributes to metabolism and biochemistry. Signup and view all the answers

What does the term 'pattern' refer to in the context of the Theory of Evolution by Natural Selection?

The consistent changes in characteristics of a population over time. Signup and view all the answers

Which concept is NOT included in the major unifying theories of biology as mentioned in the content?

Quantum Mechanics Signup and view all the answers

What adaptation do icefish have to survive in extreme environments?

Thinner blood Signup and view all the answers

Why do icefish still possess parts of the hemoglobin gene despite lacking hemoglobin?

They evolved from species that had hemoglobin. Signup and view all the answers

What is a key difference between human chromosomes and those of other great apes?

Humans have fewer chromosome pairs. Signup and view all the answers

What is unlikely regarding the missing 24th chromosome pair in humans?

It was completely lost. Signup and view all the answers

Which event led to the formation of human chromosome 2?

End-to-end fusion of two ancestral chromosomes Signup and view all the answers

What do vestigial telomeres in humans indicate?

Remnants of past evolution and chromosome fusion. Signup and view all the answers

What is a characteristic feature of icefish's anatomical structure?

Blood lacking hemoglobin. Signup and view all the answers

How does the study of chromosomes contribute to the understanding of evolution?

It helps identify the genetic similarities and differences among species. Signup and view all the answers

What does convergent evolution demonstrate?

Unrelated organisms adapt similarly to the same environment. Signup and view all the answers

Which of the following is an example of analogous features?

The wings of a bat and the wings of a bird. Signup and view all the answers

What drives adaptive radiation in divergent evolution?

The availability of diverse habitats and resources. Signup and view all the answers

What are the large layered structures formed by cyanobacteria called?

Stromatolites Signup and view all the answers

How does biogeography support Darwin's theory of evolution?

It illustrates that species close in location are more related than those farther away. Signup and view all the answers

How long were prokaryotes the only cellular form of life based on the fossil record?

2.1 billion years Signup and view all the answers

What is the significance of the fossil record in evolutionary biology?

It helps track the changes and transitions of species over time. Signup and view all the answers

What major event in the evolution of cells came after eukaryotes?

Multicellularity Signup and view all the answers

What concept refers to similar traits in organisms that do not share a recent common ancestor?

Convergence Signup and view all the answers

Which of the following was an essential step in the origin of eukaryotic cells?

Endosymbiogenesis Signup and view all the answers

In the context of evolution, which statement about homology is correct?

They indicate shared ancestry among different species. Signup and view all the answers

What does the fossil record primarily reveal regarding the history of life on Earth?

Evolution of life forms such as prokaryotes and eukaryotes Signup and view all the answers

What event contributed to the isolation of marsupials in Australia?

The break-up of the supercontinent Pangea. Signup and view all the answers

At what point in the evolutionary timeline did true multicellularity emerge?

1.8 billion years ago Signup and view all the answers

What is the first major event in the evolution of cells?

Abiogenesis Signup and view all the answers

Which option lists the major events in order of the evolution of cells?

Abiogenesis - Protocells - Prokaryotes - Multicellularity Signup and view all the answers

What is the initial stage in the evolution of cells?

Abiogenesis Signup and view all the answers

What do protocells primarily consist of?

Phospholipids Signup and view all the answers

Why is RNA considered significant in early life forms?

It acts both as an informational storage and an enzyme. Signup and view all the answers

Which of the following characteristics describes prokaryotes?

They are simple and lack internal compartments. Signup and view all the answers

What significant biochemistry evolved in prokaryotes?

DNA replication and protein synthesis Signup and view all the answers

What structure results from the chemical properties of phospholipids in water?

Liposomes and micelles Signup and view all the answers

In which era did prokaryotes exist alone for 2.1 billion years?

The prokaryote era Signup and view all the answers

What does the theory of endosymbiogenesis explain?

The origin of eukaryotic cells from prokaryotic ancestors Signup and view all the answers

Study Notes

Biology 1 - Cells, Molecular Biology, and Genetics (Biol 1000)

This course covers cells, molecular biology, and genetics.
The professor is Dr. Michael Cardinal-Aucoin.
The course is for Winter 2025.
The school is York University.

Evolution

Evolution is a major unifying theory in biology.
Darwinian evolution describes natural selection.
Evidence and examples of evolution were discussed.

Major Unifying Concepts Of Biology

Theory of Evolution by Natural Selection
Cell Theory
Genetics
Homeostasis

A Note about Theories

In everyday language, "theory" often means a guess or speculation.
In science, a theory is a broad explanation supported by multiple lines of evidence.
Scientific theories have withstood rigorous testing.

Two Major Unifying Concepts of Biology

Theory of Evolution by Natural Selection:
- Characteristics of a population change over time (pattern).
- Individuals with certain traits produce more offspring than those without (mechanism).
- All species are related by descent from a common ancestor.
- All species come from pre-existing species.
Cell Theory:
- All organisms are made up of cells (pattern).
- All cells come from pre-existing cells (mechanism).
- All cells in a multicellular organism descend from an ancestral cell.

Modern Cell Theory

A cell is the smallest self-reproducing unit of life.
Cells make up all living things.
New cells arise from pre-existing cells.
The activity of an organism depends on the total activity of independent cells.
Energy flow occurs within cells.
Cells contain hereditary information (DNA and RNA).
Cells of similar organisms share similar chemical composition.

Cells

All cells share certain properties, but not all are identical.
Plant cells, animal cells, and bacteria were shown.

Different Types of Cells

Four basic features of all cells:
- Plasma membrane
- Cytosol (semifluid substance)
- Genetic material (at some point)
- Ribosomes (to make proteins)

Units of Measure

Micrometer (µm): 1,000,000 µm = 1 meter; e.g., strand of hair has diameter ~20-180 µm
Nanometer (nm): 1,000,000,000 nm = 1 meter; e.g., wavelength of visible light ~400-700 nm
Angstrom (Å): 10,000,000,000 Å = 1 meter; used to measure atoms/bond lengths

Introduction to the Cell

A diagram showing the relative sizes of various biological entities on a logarithmic scale was presented.

Why Study Cells?

Cells are the fundamental functional units of all living things.
Cell theory is a unifying principle in biology.
Understanding cells provides insight into the functions of organisms (e.g., plants, animals, parasites, fungi).
Knowledge of cells is essential for understanding human health and diseases.
Knowledge of cells important for treatments development.

Evolution by Natural Selection

Differences exist between individuals within a population.
These differences are heritable, passed from one generation to the next.
Some individuals leave more offspring than others.
Over time these differences in population change based on reproduction and differential survival.

Natural Selection Mechanisms

Artificial selection (by humans)
Sexual selection (competition for mates)
Genetic drift (random chance)
Gene flow (movement between populations)

Evidence for the Theory of Evolution by Natural Selection

Many visuals of evidence of the theory in several forms were included (e.g., examples, pictures, etc)

Darwin's Quote

"It is not the strongest of the species that survives, nor the most intelligent, but the one most adaptable to change."

How Natural Selection Works

Environmental resources are limited, so organisms compete for them.
Organisms vary extensively in traits.
Beneficial traits provide an advantage.
Individuals with advantageous traits leave more offspring.
Heritable beneficial traits become more common over time.
The population evolves.

Genotype and Phenotype

Genotype: genetic makeup of an organism
Phenotype: observable characteristics resulting from the interaction of genotype and environment

Evolution, Genotype, Phenotype, Environment

Evolution is the interplay between genotype, phenotype, and the environment.
Genotype influences phenotype.
Environmental influences affect phenotype.
Through evolution, advantageous characteristics become increasingly frequent in a population.

Macroevolution and Microevolution

Macroevolution represents large-scale changes that occur over millions of years, and result from many incremental modifications.
Microevolution involves small-scale changes within a population's traits over relatively short periods.

The Vastness of Evolutionary Time

Estimates for the age of the Earth, human generations, etc. were presented in the context of evolutionary time.

Evidence for Evolution

Extensive evidence supports evolution through homology, universal genetic code, fossils, genomics, insecticide resistance, and biogeography.

Biogeography and Species Distributions

Species are more closely related to those in the same geographic area.
Geographic distribution reflects divergence from common ancestors into different habitats.

Fossil Record

Oldest fossils from around 4 billion years ago (mya)
Cyanobacteria (blue-green algae): oldest fossils in the Precambrian Period.
Cyanobacteria also formed large layered structures called stromatolites.
Fossils of single-celled eukaryotes around 1.8 bya.
Multicellularity occurred around 1.8 to 1.5 bya.
Evolution created varied species through multiple lineages over time.

How is Evolution Relevant to Cell Biology?

Understanding the evolution of cells
- How cells evolved.
- Their history
- The diversity of cells
- Common features of cells
How cells have adapted to various environments

Main Events in the Evolution of Cells

Abiogenesis (first life)
Protocells (early life forms)
RNA world (early genetic material)
Prokaryotes (first cells)
Endosymbiosis (origin of eukaryotic organelles)
Eukaryotes (cells with nuclei)
Multicellularity (formation of complex organisms)

Abiogenesis

Prebiotic synthesis- molecules forms spontaneously.
No fossil records but can study in lab.
Molecules of life can be formed through lab conditions replicating early earth conditions.

Protocells

Formation of micelles and liposomes as chemical products resulting in the formation of the first cells
Hydrophilic heads together, and hydrophobic tails together.

RNA World

RNA has properties of both DNA and proteins.
Many scientists think RNA, not DNA, was the first genetic material on Earth.

Prokaryotes

Small, simple cells without internal compartments.
Evolved most biochemistry that is present in life forms today
DNA replication/genetic code
Protein synthesis
Photosynthesis
Anaerobic and aerobic metabolism

Endosymbiosis

Some organelles (e.g. mitochondria and chloroplasts) likely evolved from free-living prokaryotes that were engulfed by larger cells.

Eukaryotes

Cells with nuclei and other internal compartments
Larger than prokaryotic cells
More complex structures and functions
True multicellularity
Multiple chromosomes, mitosis, meiosis, and increased genetic diversity

Multicellularity

First multicellular organisms appeared around 2.7 billion years ago (bya).
Multicellularity arose multiple times.
Strong selective advantage over time.

Advantages of Multicellularity

Increased size
Competition for food
Protection from predators
Division of labour
Increased complexity
Overcome limits to cell size

Eukaryotes as Evolution's Major Achievement

Eukaryotic cells are evolution's major achievement, building upon prokaryotic cells

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Test your understanding of basic cell features and their significance in biology. This quiz covers essential concepts regarding cellular structures, functions, and their roles in living organisms. Ideal for students studying cell biology and related topics.