Grade 9 Biology

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Questions and Answers

Define Biology.

Biology is the scientific study of life or living things.

What are the common characteristics of living things?

Living things are composed of one or more cells, they can grow, reproduce, transmit genetic information to their offspring, need energy to accomplish work, maintain relatively constant internal conditions (homeostasis), and are capable of evolutionary adaptation to the environment.

What is the scientific method?

Biologists study about living things using a scientific method that involves asking questions, suggesting possible answers, and testing for the validity of the answers through experimentation.

How many lenses does a hand lens have?

one Signup and view all the answers

What is the total magnification of a compound light microscope with a ×10 eyepiece and a ×40 objective lens?

400 Signup and view all the answers

What is the main function of a hand lens?

To provide an enlarged image of the object placed under it. Signup and view all the answers

What are the major types of microscopes?

Electron microscope Signup and view all the answers

A hypothesis should be testable.

True Signup and view all the answers

The scientific study begins with careful ________ that lead to a question.

observations Signup and view all the answers

Is it possible to define life in a simple sentence? If your answer is no, why not?

Yes, it is possible to define life in a simple sentence. Signup and view all the answers

How are living things different from non-living things?

Living things have the capacity for growth, reproduction, functional activity, and continual change, which non-living things lack. Signup and view all the answers

Why do biologists classify living things?

Biologists classify living things to organize the study of organisms, identify relationships between species based on similarities and differences, and reveal evolutionary patterns and connections. Signup and view all the answers

What is taxonomy?

Taxonomy is the science of naming and classifying species. Signup and view all the answers

Who introduced the taxonomic hierarchy in biological classification?

Carolus Linnaeus Signup and view all the answers

What is the standard magnification of the eyepiece in a light microscope?

10x Signup and view all the answers

Which part of the microscope holds multiple objective lenses?

Nose piece Signup and view all the answers

It is forbidden to eat or drink in the science laboratory.

True Signup and view all the answers

To minimize the damage done by a burn, the affected area should be flooded with _____ tap water for several minutes.

cold Signup and view all the answers

How do biologists use dichotomous keys?

To identify unfamiliar organisms Signup and view all the answers

What is the purpose of a dichotomous key?

The purpose of a dichotomous key is to help identify unfamiliar organisms by simplifying the identification process. Signup and view all the answers

Viruses are considered to be living organisms.

False Signup and view all the answers

What is the purpose of the five-kingdom system of classification?

To classify all known organisms Signup and view all the answers

What is taxonomic hierarchy?

Taxonomic hierarchy is a group of organisms that share a unique set of traits. Signup and view all the answers

List some taxonomic hierarchies that you know.

Some examples of taxonomic hierarchies include domain, kingdom, phylum, class, order, family, genus, and species. Signup and view all the answers

For which of the following purposes could taxonomy be used?

All of the above Signup and view all the answers

What is binomial nomenclature?

Binomial nomenclature is the internationally agreed system of naming organisms comprising two parts: the genus and the species. Signup and view all the answers

Write the scientific names of the following organisms: house fly, mouse, dog, cat & goat.

House fly: Musca domestica, Mouse: Mus musculus, Dog: Canis lupus familiaris, Cat: Felis catus, Goat: Capra aegagrus hircus Signup and view all the answers

Which of the following is not a property of life?

Populations of organisms rarely change over time Signup and view all the answers

Which of the following is the correct procedure of scientific method?

Observation question hypothesis prediction, experiment results conclusion Signup and view all the answers

Hypothesis in biology is best described as...

Possible explanation of an observation Signup and view all the answers

Write the main difference between light and Electron microscope.

The main difference is that light microscopes use visible light to illuminate specimens, while electron microscopes use a beam of electrons. Signup and view all the answers

Why does a microscope have several objective lenses?

A microscope has several objective lenses to provide different levels of magnification for viewing specimens. Signup and view all the answers

What will happen to the field of view in a microscope as you close the diaphragm?

Closing the diaphragm in a microscope will decrease the amount of light entering the lens, resulting in a darker field of view. Signup and view all the answers

Why should you always focus a microscope by moving the objective lens away from the specimen?

Focusing a microscope by moving the objective lens away from the specimen prevents damage to the lens or specimen. Signup and view all the answers

Explain the importance of adding oil immersion when using high power objective? How?

Oil immersion is important when using a high power objective as it allows for better resolution and prevents light refraction. The oil has the same refractive index as glass, reducing light loss and increasing clarity. Signup and view all the answers

List at least three field tools used by biologists.

Three field tools used by biologists are binoculars, compass, and field guides. Signup and view all the answers

Study Notes

Introduction to Biology

Definition of Biology: the scientific study of life or living things
Biology is derived from two Greek words: "bios" meaning life and "logos" meaning study
Characteristics of living things:
- Composed of one or more cells
- Grow and reproduce
- Transmit genetic information to offspring
- Need energy to accomplish work
- Maintain relatively constant internal conditions (homeostasis)
- Capable of evolutionary adaptation to the environment

Importance of Biology

Biology is applied in various fields such as:
- Agriculture
- Medicine
- Food processing
- Preparation of beverages
Biological applications in daily life:
- Wine-making
- Brewing
- Baking bread
- Producing cheese
- Fermentation processes brought about by yeasts, fungi, or bacteria
- Antibiotics production
- Industrial chemicals production
- Sewage disposal
- Forensic analysis of DNA samples

The Scientific Method

Steps of the scientific method:
1. Observation
2. Asking questions
3. Forming a hypothesis
4. Testing the hypothesis
5. Making conclusions about the findings
6. Communicating the findings
Hypothesis: a proposed scientific explanation
Example of hypothesis testing in everyday life: finding a missing pen using a torch that doesn't work
Application of the scientific method to common problems in our surroundings
Importance of temperature for seed germination: experiment with different temperatures and measure germination times and seedling length.### Tools of a Biologist
Hand lens: a tool used to magnify objects, has a convex lens fixed within a circular metallic loop and attached to a handle, provides an enlarged image of objects
Microscope: an instrument used to study small objects, magnifies images making them visible to the human eye
- Types of microscopes: light microscope, electron microscope
- Light microscope: uses a beam of light to view specimens, has two types: simple light microscope (single lens) and compound light microscope (two or more glass lenses)
- Electron microscope: uses a beam of electrons and electromagnets to enlarge images, provides higher magnification than light microscopes
Autoclave: equipment used to sterilize biological samples, kills microorganisms using high temperatures and pressurized steam
Incubator: device used to maintain a specific environment for culturing microorganisms
Petri dishes: flat dishes with a matching cover, used with gelling culturing media and sterilized in an autoclave
Culture tubes: used to culture microorganisms, available in various sizes and materials
Flasks: apparatus used for gently heating and mixing solutions, available in various shapes and sizes
Balance: used for making accurate measurements, weighing specimens, and making solutions
Dropper: used to control the amount of solution being added to a reaction
Tongs: used to lift or pick up hot objects
Dissecting tool kit: used to dissect animals, includes tools such as a catheter, groove probe, scalpel, and dissecting forceps
Dissecting pan: used as a pan on which the specimen is kept during dissection
Crucible: a small container made of ceramic or metal, used to melt elements
Beaker: a cylindrical glass container used for making solutions, holding hot or cold water, and more
Hotplate: used for heating solutions and making up an agar culturing medium
pH meter: used to measure the pH of substances
Thermometer: used to measure the temperature of substances
Forceps: used to hold or pick up small objects
Spatula: used for mixing substances into a solution, stirring, and scraping objects
Wash bottles: used to rinse laboratory materials, flexible and adjustable water pressure
Bunsen burner or alcohol burner: used for heating and sterilization purposes
Insect net: used for collecting insects
Fishing net: used for fishing, also known as fish traps

Light Microscope

Parts of a light microscope:
- Eyepiece (ocular): used to look through the microscope, standard magnification is 10x with optional eyepieces having magnifications from 5x to 30x
- Eyepiece tube: holds the eyepiece just above the objective lens
- Objective lenses: major lenses that further magnify the specimen at different intensities, typically with magnification powers of 4x-100x
- Arm: holder that connects all components, supports the microscope
- Body tube: connects the eyepiece to the objective lenses
- Nose piece: rotating mount that holds multiple objective lenses, movable to change magnification
- Adjustment knobs: used to focus the microscope, including fine adjustment knobs and coarse adjustment knobs### Characteristics of Living Things
Living things can be identified by a series of characteristics shared by all living systems
Characteristics of living things:
- Made up of one or more cells (unicellular or multi-cellular)
- Require energy for metabolic activities
- Respond to stimuli (detect and sense changes in internal or external environment)
- Can grow (permanent increase in size and mass due to cell number or size increase)
- Can reproduce (make more of the same kind of organism)
- Can excrete (remove metabolic waste products from cells)
- Display ordered complexity (complex and highly ordered systems, increasing in complexity from atoms to molecules to cells)
- Maintain homeostasis (maintain relatively constant internal conditions different from the environment)

Importance of Understanding Living Things

Understanding living things helps distinguish between living and non-living things
Characteristics of living things apply to all life forms, from single-celled organisms to complex organisms like humans

Classification of Living Things

Taxonomy: the science of classifying living things
Importance of classification: helps understand relationships between organisms, understand evolutionary history, and identify organisms

Taxonomic Hierarchy

Kingdoms: Monera, Protista, Fungi, Plantae, Animalia
Each kingdom has characteristic features
Understanding taxonomic hierarchies helps understand relationships between organisms

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