Biology Cell Structure and Functions Quiz

Questions and Answers

What role do mitochondria play in the cell?

Store water and nutrients

Provide energy for the cell (correct)

Transport proteins and substances

Make proteins

What is the primary function of the nucleus in a cell?

Provide energy for the cell

Store water and nutrients

Make proteins

Control and regulate the cell (correct)

Which cellular process primarily occurs in chloroplasts?

Cell division

Cellular respiration

Protein synthesis

Photosynthesis (correct)

What is the correct equation for cellular respiration?

Glucose + oxygen > carbon dioxide + water Signup and view all the answers

What is one key difference between autotrophs and heterotrophs?

Autotrophs make their own food Signup and view all the answers

What are the two stages of photosynthesis called?

Light reaction and Calvin cycle Signup and view all the answers

What does ATP stand for?

Adenosine triphosphate Signup and view all the answers

In which type of cells does aerobic cellular respiration primarily occur?

Eukaryote cells Signup and view all the answers

What describes the interaction where one organism benefits while the other is harmed?

Parasitism Signup and view all the answers

Which step in the development of antibiotic resistance in bacteria involves a change in DNA?

Variation Signup and view all the answers

What is the role of selection pressure in natural selection?

It favors survival of certain variations. Signup and view all the answers

Which relationship describes both organisms benefiting from their interaction?

Mutualism Signup and view all the answers

Which of the following is an example of allelopathy?

Skunks producing chemicals harmful to other plants Signup and view all the answers

What is meant by competition in the context of intraspecific interactions?

Competition among members of the same species Signup and view all the answers

Which of the following correctly represents the definition of a pathogen?

A disease-causing organism Signup and view all the answers

How does sexual selection differ from natural selection?

It emphasizes mate selection for reproduction. Signup and view all the answers

What climatic changes are evidenced by fossilised pollen grains dated over 76,000 years ago in arid areas of Australia?

The areas were cooler and wetter. Signup and view all the answers

What has been the climate trend in Australia over the last 27,000 years according to fossil evidence?

The climate has shifted to warmer and drier. Signup and view all the answers

What is indicated by the pentadactyl limb structure observed in whales, bats, horses, and humans?

They share a common ancestor. Signup and view all the answers

Which of the following evidence supports the concept of evolution through embryology?

All vertebrate embryos exhibit gill slits and tails. Signup and view all the answers

What does biogeography illustrate about the evolution of old world and new world monkeys?

Geographic isolation led to their differences. Signup and view all the answers

What does the current low diversity of sclerophyll flora in south-eastern Australia imply?

There were historical extinctions that reduced diversity. Signup and view all the answers

How can a single species impact others in the community?

Through competition for resources. Signup and view all the answers

Which factor primarily led to the evolution of various species within a community?

Geographic variations and isolation. Signup and view all the answers

What primarily holds the secondary structure of a protein together?

Hydrogen bonds Signup and view all the answers

What is the difference between a polypeptide chain and a peptide bond?

A peptide bond forms between amino acids, while a polypeptide chain is a series of many amino acids. Signup and view all the answers

Why is the tertiary structure of a protein crucial for enzyme function?

It gives the enzyme its 3D shape, including the active site. Signup and view all the answers

How does temperature affect enzyme activity?

Optimal temperature increases activity until it denatures. Signup and view all the answers

What structural feature varies between different amino acids?

Variable group Signup and view all the answers

Which factor does NOT affect enzyme activity?

Electric charge of the enzyme Signup and view all the answers

What happens to an enzyme at temperatures above its optimal point?

Enzyme denatures and loses its function. Signup and view all the answers

Increasing the substrate concentration affects enzyme activity up to a certain point. What is this point called?

Saturation point Signup and view all the answers

What is considered the most dominant reason for land degradation?

Human-induced processes Signup and view all the answers

Which of the following activities contributes to land degradation?

Over-grazing by livestock Signup and view all the answers

What is a significant consequence of habitat clearing?

Loss of genetic diversity Signup and view all the answers

Which region is currently most affected by land degradation?

South America Signup and view all the answers

What happens to populations as habitats become increasingly fragmented?

They become more vulnerable to threats Signup and view all the answers

What is a strategy to combat land degradation?

Site stabilisation Signup and view all the answers

Which of the following is NOT a cause of land degradation?

Afforestation efforts Signup and view all the answers

What is one effect of wildlife extinction on ecosystems?

Reduced ecological interactions Signup and view all the answers

Study Notes

Cell Structure and Functions

Cytoplasm: Nutrient-rich fluid housing organelles.
Mitochondria: Energy production for the cell.
Ribosomes: Protein synthesis.
Nucleus: Location of DNA control and regulation.
Endoplasmic Reticulum: Transports proteins and substances within the cell.
Golgi Apparatus: Folds, packages, and directs proteins to their destinations.
Vacuole: Storage for water and nutrients; helps maintain cell rigidity.
Chloroplasts: Site of photosynthesis, providing food and energy for cells.

Autotrophs vs. Heterotrophs

Autotrophs: Produce their own food.
Heterotrophs: Consume complex organic compounds from other organisms.

Photosynthesis Equation

Water + Carbon Dioxide → Glucose + Oxygen (in the presence of chlorophyll)

Cellular Respiration Overview

Process where glucose reacts with oxygen to release energy.
Energy is stored as ATP (adenosine triphosphate).

Aerobic Cellular Respiration

Occurs in eukaryotic cells, which contain a nucleus.

Photosynthesis vs. Cellular Respiration

Photosynthesis: Plants convert light energy into glucose.
Cellular Respiration: Animals break down glucose to release energy.

Cellular Respiration Equation

Glucose + Oxygen → Carbon Dioxide + Water + Energy (ATP)

Protein Structure

Proteins are chains of amino acids.
Amino acids: Comprise an amino group, carboxylic acid group, variable group, bonded at a central carbon atom.
Peptide Bond: Formed between amino acids via a condensation reaction, releasing water.

Structure Types of Proteins

Primary: Sequence of amino acids.
Secondary: Polypeptide chain folds, stabilized by hydrogen bonds.
Tertiary: 3D shape formed by further folding, essential for enzyme function.

Importance of Protein Structure for Enzymes

The 3D shape, including the active site, enables substrate binding and lowers activation energy.

Factors Affecting Enzyme Activity

Temperature: Increasing temperature raises reaction rates to an optimum, beyond which, the enzyme denatures.
pH: Each enzyme has an optimal pH; deviations cause denaturation and reduced activity.
Substrate Concentration: Higher levels increase rates of reaction up to a saturation point.

Community Interactions

Predator-Prey: One organism feeds on another (e.g., dolphins eat fish).
Interspecific Competition: Different species compete for resources (e.g., squirrels over habitat).
Intraspecific Competition: Same species compete for resources (e.g., monkeys over food).
Allelopathy: One organism releases harmful chemicals affecting another (e.g., skunks on maple pine).
Parasitism: One benefits at the other's expense (e.g., ticks).
Commensalism: One benefits while the other is unaffected (e.g., barnacles on whales).
Mutualism: Both organisms benefit (e.g., bees and flowers).

Antibiotic Resistance

Antibiotic: Chemical that harms bacteria, can be natural or synthetic.
Penicillin: Example of an antibiotic.
Pathogen: Disease-causing organism.
Mutation: DNA change that can be beneficial or harmful.

Bacteria Resistance Development

Steps: Variation, Selection Pressure, Inheritance, Gradual Changes in Population.

Natural and Sexual Selection

Natural Selection: Favors survival of variations leading to reproduction.
Sexual Selection: A form of natural selection focusing on reproductive partners.

Evidence of Evolution

Comparative Anatomy: Common ancestry reflected in limb structures across species.
Embryology: Shared features among vertebrate embryos, like gill slits.
Biogeography: Geographic separation (e.g., Pangea) leading to species divergence.

Community Impact of Species

Species dominance alters community dynamics, leading to soil and habitat degradation.
Human activities: Agriculture, grazing, and logging contribute to land degradation.
Habitat loss due to human activities can trigger extinction risks.
Restorative actions allow ecosystems to recover over time.

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Description

Test your knowledge on the various structures and functions of a cell, including organelles like mitochondria, ribosomes, and chloroplasts. Additionally, explore the differences between autotrophs and heterotrophs, as well as the processes of photosynthesis and cellular respiration.