Selective Breeding 2

Uses of Selective Breeding

Usefulness and appearance are the two most common reasons for a characteristic being considered desirable. Some useful examples are:

Crops

Disease resistance in food crops is a useful characteristic because it improves yield (food production productivity).

Animals

In farming, animals that produce more milk or meat are also useful for yield-related reasons.

Dogs

Gentle-natured domestic dogs are useful as these animals must co-exist (live with) with humans.

Flowers

Flowers can be selected based on visual criteria, such as size or colour.

Dangers of Selective Breeding

Selective breeding can create some problems:

Inbreeding

Selective breeding can lead to inbreeding. Here, some breeds become particularly susceptible to disease or inherited defects.
- For example, French bulldogs have been selectively bred to have flat faces, but that causes them breathing problems.

Reduced variation

Selective breeding can reduce variation (differences in characteristics) within a population, making it harder for a species to adapt to environmental change.

1Cell Biology

1.1What's in Cells?

1.1.1Types of Cells

1.1.2Properties of Prokaryotes

1.1.3Standard Form

1.1.4Standard Form - Calculations

1.1.5Addition in Standard Form - Calculations

1.1.6Subtraction in Standard Form - Calculations

1.1.7Multiplication in Standard Form - Calculations

1.1.8Division in Standard Form - Calculations

1.1.9Animal Cells

1.1.10Plant Cells

1.1.11Differences Between Animal & Plant Cells

1.1.12Bacterial Cells

1.1.13Types of Cells HyperLearning

1.1.14Cell Specialisation in Animals

1.1.15Sperm Cells

1.1.16Nerve Cells

1.1.17Muscle Cells

1.1.18Cell Specialisation in Plants

1.1.19Microscopy

1.1.20Developments in Microscopy

1.1.21Microscope Practical

1.1.22Microscopy - Calculations

1.1.23Culturing Microorganisms

1.1.24Contamination

1.1.25Avoiding Contamination

1.1.26Calculating Bacteria

1.1.27Calculating Bacteria - Calculations

1.1.28End of Topic Test - What's in Cells?

1.1.29Exam-Style Questions - Cell Structure & Microscopy

1.2Cell Division

1.2.1Chromosomes

1.2.2The Cell Cycle

1.2.3Mitosis

1.2.4Exam-Style Questions - Mitosis & Cell Cycle

1.2.5Stem Cells

1.2.6Use of Stem Cells

1.2.7Disadvantages of Stem Cells

1.3Transport in Cells

1.3.1Diffusion

1.3.2Factors Affecting Diffusion

1.3.3Surface Area : Volume

1.3.4Surface Area : Volume - Calculations

1.3.5Exchange Surfaces

1.3.6Examples of Exchange Surfaces

1.3.7Osmosis

1.3.8Osmosis Practical

1.3.9Active Transport

1.3.10Transport in Cells

1.3.11End of Topic Test - Cell Division & Transport

1.3.12Grade 9 - Cell Transport

2Organisation

2.1Principles of Organisation

2.1.1Cells & Tissues

2.1.2Organs

2.1.3Organ Systems

2.1.4Organisms

2.2Enzymes

2.2.1Enzymes

2.2.2Enzymes HyperFlashcards

2.2.3Rate of Reaction

2.2.4Calculating Rate of Reaction

2.2.5Rate of Reaction - Calculations

2.2.6Digestion

2.2.7Bile

2.2.8Examples of Digestive Enzymes - Amylase

2.2.9Examples of Digestive Enzymes - Protease

2.2.10Examples of Digestive Enzymes - Lipase

2.2.11Testing for Biological Molecules

2.2.12End of Topic Test - Organisation & Enzymes

2.2.13Grade 9 - Enzymes

2.2.14Exam-Style Questions - Enzymes

2.3Circulatory System

2.3.1Types of Blood Vessel

2.3.2Blood Vessels - Arteries

2.3.3Blood Vessels - Capillaries

2.3.4Blood Vessels - Veins

2.3.5The Heart - Structure

2.3.6The Heart - Function

2.3.7Important Blood Vessels

2.3.8Double Circulatory System

2.3.9Gas Exchange

2.3.10Gas exchange - Calculations

2.3.11Alveoli

2.3.12Blood Components

2.3.13Platelets

2.3.14Red Blood Cells

2.3.15White Blood Cells

2.3.16End of Topic Test - Circulatory System

2.4Non-Communicable Diseases

2.4.1Health Issues

2.4.2Disease Interactions

2.4.3Sampling

2.4.4Sampling - Calculations

2.4.5Risk Factors

2.4.6Examples of Risk Factors

2.4.7Risk Factor Graphs

2.4.8Coronary Heart Disease

2.4.9Heart Valve Disease

2.4.10Heart Failure

2.4.11Treating Heart Disease

2.4.12Cancer

2.4.13Cancer Risk Factors

2.4.14End of Topic Test - Non-Communicable Diseases

2.4.15Exam-Style Questions - Coronary Heart Disease

2.5Plant Tissues, Organs & Systems

2.5.1Plant Tissues

2.5.2Leaves

2.5.3Transpiration

2.5.4Rate of Transpiration

2.5.5Measuring Transpiration

2.5.6Translocation

2.5.7Transpiration Tissues

2.5.8Stomata

2.5.9Premium Knowledge - Transpiration

2.5.10End of Topic Test - Plants

2.5.11Exam-Style Questions - Plant Tissues

3Infection & Response

3.1Communicable Disease

3.1.1Spreading Disease

3.1.2Viruses

3.1.3Other Pathogens

3.1.4Human Defence Systems

3.1.5Human Defence Systems 2

3.1.6Grade 9 - Immune System

3.1.7Antibiotics

3.1.8Drug Development

3.1.9Drug Testing

3.1.10Drug Testing / Efficacy - Calculations

3.1.11End of Topic Test - Communicable Diseases

3.1.12Exam-Style Questions - Microorganisms & Disease

3.2Monoclonal Antibodies

3.2.1Producing & Using Monoclonal Antibodies

3.2.2Grade 9 - Monoclonal Antibodies

3.3Plant Diseases

3.3.1Diseases & Defence

3.3.2Identifying Disease

3.3.3End of Topic Test - Antibodies & Plant Disease

4Bioenergetics

4.1Photosynthesis

4.1.1Photosynthesis

4.1.2Photosynthesis 2

4.1.3Photosynthesis - Calculations

4.1.4Photosynthesis Experiments

4.1.5Grade 9 - Photosynthesis Experiment

4.1.6Exam-Style Questions - Rate of Photosynthesis

4.2Respiration

4.2.1Respiration

4.2.2Respiration - Calculations

4.2.3Exercise

4.2.4Respiration HyperLearning

4.2.5End of Topic Test - Photosynthesis and Respiration

4.2.6Exam-Style Questions - Anaerobic Respiration

5Homeostasis & Response

5.1Homeostasis

5.1.1Homeostasis

5.1.2Homeostasis & Negative Feedback

5.1.3Exam-Style Questions - Exercise & Homeostasis

5.2The Human Nervous System

5.2.1The Nervous System

5.2.2The Nervous System HyperFlashcards

5.2.3Synapses

5.2.4Reflexes

5.2.5Exam-Style Questions - Nervous System

5.2.6The Brain

5.2.7Eye Anatomy

5.2.8Eye Function

5.2.9Control of Body Temperature

5.2.10Warming Up & Cooling Down

5.2.11Body Temperature HyperLearning

5.2.12End of Topic Test - Human Nervous System

5.3Hormonal Coordination in Humans

5.3.1Endocrine System

5.3.2Thyroxine & Adrenaline

5.3.3Blood Glucose

5.3.4Diabetes

5.3.5Control of Water Balance

5.3.6Urine

5.3.7Dialysis

5.3.8Transplants

5.3.9Puberty

5.3.10Menstruation

5.3.11Contraception

5.3.12Contraception 2

5.3.13Hormones for Infertility

5.3.14End of Topic Test - Homeostasis & Hormones

5.3.15Grade 9 - Hormonal Coordination

5.3.16Exam-Style Questions - Hormones & Contraception

5.4Plant Hormones

5.4.1Plant Hormones

5.4.2Plant Hormones 2

5.4.3End of Topic Test - Hormones

6Inheritance, Variation & Evolution

6.1Reproduction

6.1.1Reproduction

6.1.2Reproduction 2

6.1.3Genome

6.1.4DNA

6.1.5Protein Synthesis

6.1.6Genetic Inheritance

6.1.7Genetic Crosses

6.1.8Inherited Disorders

6.1.9Inherited Disorders 2

6.1.10Genetic Crosses - Calculations

6.1.11Genome Screening & Sex Determination

6.1.12End of Topic Test - Reproduction

6.1.13Exam-Style Questions - DNA & Genetics

6.2Variation & Evolution

6.2.1Variation & Evolution

6.2.2Selective Breeding

6.2.3Selective Breeding 2

6.2.4Genetic Engineering

6.2.5Uses of Genetic Modification

6.2.6Cloning

6.2.7Cloning 2

6.2.8End of Topic Test - Variation & Evolution

6.2.9Exam-Style Questions - Selective Breeding

6.3Genetics & Evolution

6.3.1Natural Selection

6.3.2Speciation

6.3.3Evidence for Evolution

6.3.4Genetics & Extinction

6.3.5Grade 9 - Evolution

6.4Classification

6.4.1Classification of Living Organisms

6.4.2Classification of Living Organisms 2

6.4.3End of Topic - Genetics & Classification

7Ecology

7.1Adaptations & Interdependence

7.1.1Communities

7.1.2Communities 2

7.2Organisation of Ecosystems

7.2.1Population Dynamics

7.2.2Environmental Change

7.2.3Assessing Ecosystems

7.2.4Assessing Ecosystems - Calculations

7.2.5The Cycling of Materials

7.2.6Decay

7.2.7Decay Practical

7.2.8End of Topic Test - Organisation of Ecosystems

7.2.9Grade 9 - Ecosystems

7.2.10Exam-Style Questions - Decomposition

7.3Biodiversity

7.3.1Human Interactions with Ecosystems

7.3.2Human Interactions with Ecosystems 2

7.3.3Greenhouse Gases

7.3.4Greenhouse Gases 2

7.3.5Hardest Questions - Humans & the Environment

7.3.6End of Topic Test - Adaptations & Biodiversity

7.4Trophic Levels

7.4.1Trophic Levels

7.4.2Trophic Levels 2

7.4.3Transfer efficiency - Calculations

7.4.4Premium Knowledge - Trophic Levels & Food Chains

7.4.5Exam-Style Questions - Food Chains

7.5Food Production

7.5.1Food Production

7.5.2Farming & Fishing

7.5.3Food Production - Calculations

7.5.4End of Topic Test - Food & Trophic Levels

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