10th Biology: Ecology

• 10th Biology encompasses core biological concepts typically introduced in a tenth-grade curriculum.

Ecology

• Ecology is the study of the interactions between living organisms and their environment.
• An ecosystem consists of all the living organisms in a particular area, along with the non-living components of the environment, such as air, water, and soil.
• Biotic factors are the living components of an ecosystem, including plants, animals, and microorganisms.
• Abiotic factors are the non-living components of an ecosystem, such as temperature, sunlight, and water availability.
• Producers, like plants, convert sunlight into energy through photosynthesis.
• Consumers obtain energy by feeding on other organisms; primary consumers eat producers, secondary consumers eat primary consumers, and so on.
• Decomposers break down dead organic matter, recycling nutrients back into the ecosystem.
• Food chains illustrate the flow of energy from one organism to another.
• A food web is a complex network of interconnected food chains.
• Trophic levels represent the different feeding positions in a food chain or web.
• Energy transfer between trophic levels is inefficient; only about 10% of the energy is transferred to the next level.
• Biomagnification is the increasing concentration of toxins in organisms at higher trophic levels.
• Population density is the number of individuals of a species per unit area or volume.
• Carrying capacity is the maximum population size that an environment can sustain.
• Symbiosis is a close and long-term interaction between two different species, including mutualism, commensalism, and parasitism.
• Mutualism is a symbiotic relationship in which both species benefit.
• Commensalism is a symbiotic relationship in which one species benefits and the other is neither harmed nor helped.
• Parasitism is a symbiotic relationship in which one species benefits and the other is harmed.
• Climate change refers to long-term shifts in temperature and weather patterns, largely due to human activities.
• Deforestation is the clearing of forests for other land uses, contributing to habitat loss and climate change.
• Pollution is the contamination of the environment with harmful substances.

Cell Biology

• Cell biology is the study of cells, their structure, function, and behavior.
• The cell is the basic unit of life.
• The cell theory states that all living organisms are composed of cells, cells are the basic units of structure and function in living organisms, and all cells arise from pre-existing cells.
• Prokaryotic cells lack a nucleus and other membrane-bound organelles; bacteria and archaea are prokaryotes.
• Eukaryotic cells have a nucleus and other membrane-bound organelles; plants, animals, fungi, and protists are eukaryotes.
• The plasma membrane is the outer boundary of the cell, regulating the movement of substances in and out.
• The cytoplasm is the gel-like substance within the cell, containing organelles and other cellular components.
• The nucleus contains the cell's genetic material (DNA) and controls cellular activities.
• Ribosomes are responsible for protein synthesis.
• The endoplasmic reticulum (ER) is a network of membranes involved in protein and lipid synthesis.
• The Golgi apparatus processes and packages proteins and lipids.
• Mitochondria are the powerhouses of the cell, generating energy through cellular respiration.
• Lysosomes contain enzymes that break down cellular waste and debris.
• The cytoskeleton provides structural support and facilitates cell movement.
• Cell division is the process by which cells reproduce; mitosis and meiosis are two types of cell division.
• Mitosis is the process of cell division that results in two identical daughter cells.
• Meiosis is the process of cell division that results in four genetically different daughter cells (gametes).
• Cellular respiration is the process by which cells convert glucose into energy (ATP).
• Photosynthesis is the process by which plants convert sunlight, water, and carbon dioxide into glucose and oxygen.
• Diffusion is the movement of molecules from an area of high concentration to an area of low concentration.
• Osmosis is the movement of water across a semipermeable membrane from an area of high water concentration to an area of low water concentration.
• Active transport is the movement of molecules across a membrane against their concentration gradient, requiring energy.

Human Anatomy

• Human anatomy is the study of the structure of the human body.
• The skeletal system provides support, protection, and movement.
• Bones are the main components of the skeletal system; the human skeleton has 206 bones.
• Joints are the points where bones meet, allowing for movement.
• Ligaments connect bones to bones, providing stability to joints.
• The muscular system enables movement, maintains posture, and generates heat.
• Muscles contract to produce movement; skeletal muscles are attached to bones and are responsible for voluntary movements.
• Tendons connect muscles to bones.
• The nervous system controls and coordinates bodily functions through electrical and chemical signals.
• The brain is the control center of the nervous system.
• The spinal cord transmits signals between the brain and the rest of the body.
• Neurons are nerve cells that transmit electrical impulses.
• The endocrine system regulates bodily functions through hormones.
• Hormones are chemical messengers produced by endocrine glands.
• The cardiovascular system transports blood, oxygen, and nutrients throughout the body.
• The heart is the pump that circulates blood.
• Blood vessels include arteries, veins, and capillaries.
• The respiratory system is responsible for gas exchange, taking in oxygen and releasing carbon dioxide.
• The lungs are the main organs of the respiratory system.
• The digestive system breaks down food into nutrients that the body can absorb.
• The stomach, small intestine, and large intestine are parts of the digestive system.
• The excretory system removes waste products from the body.
• The kidneys filter blood and produce urine.
• The immune system defends the body against pathogens and diseases.
• White blood cells are part of the immune system.
• The lymphatic system helps to maintain fluid balance and plays a role in immunity.
• Lymph nodes filter lymph fluid and contain immune cells.

Evolution

• Evolution is the process by which populations of organisms change over time.
• Natural selection is the mechanism of evolution, where individuals with advantageous traits are more likely to survive and reproduce.
• Charles Darwin is credited with developing the theory of evolution by natural selection.
• Variation is the differences among individuals in a population.
• Adaptation is a trait that helps an organism survive and reproduce in its environment.
• Fitness refers to an organism's ability to survive and reproduce.
• Mutation is a change in the DNA sequence; mutations can be beneficial, harmful, or neutral.
• Genetic drift is the random change in the frequency of alleles in a population.
• Gene flow is the transfer of genetic material from one population to another.
• Speciation is the process by which new species arise.
• Allopatric speciation occurs when populations are geographically isolated.
• Sympatric speciation occurs when populations diverge in the same geographic area.
• Fossil evidence provides a record of past life and evolutionary changes.
• Comparative anatomy compares the body structures of different species.
• Homologous structures are structures that have a common evolutionary origin but may have different functions.
• Analogous structures are structures that have similar functions but different evolutionary origins.
• Vestigial structures are remnants of organs or structures that had a function in an early ancestor.
• Molecular biology studies the similarities and differences in the DNA and protein sequences of different species.

Genetics

• Genetics is the study of heredity and variation of inherited characteristics.
• Genes are units of heredity that carry information from parents to offspring.
• DNA (deoxyribonucleic acid) is the molecule that carries genetic information.
• Chromosomes are structures made of DNA and protein that contain genes.
• Alleles are different versions of a gene.
• Genotype is the genetic makeup of an organism.
• Phenotype is the observable characteristics of an organism.
• Homozygous means having two identical alleles for a gene.
• Heterozygous means having two different alleles for a gene.
• Dominant alleles are expressed when present in a heterozygous genotype.
• Recessive alleles are only expressed when present in a homozygous genotype.
• Punnett squares are used to predict the genotypes and phenotypes of offspring.
• Mendel's laws of inheritance include the law of segregation and the law of independent assortment.
• The law of segregation states that allele pairs separate during gamete formation.
• The law of independent assortment states that genes for different traits are inherited independently of each other.
• Sex-linked traits are traits that are determined by genes located on the sex chromosomes (X and Y).
• Incomplete dominance occurs when the heterozygous phenotype is intermediate between the two homozygous phenotypes.
• Codominance occurs when both alleles in a heterozygous genotype are fully expressed.
• Polygenic inheritance is when multiple genes influence a trait.
• Mutations are changes in the DNA sequence.
• Genetic engineering is the process of manipulating an organism's genes.
• Gene therapy is the use of genes to treat or prevent diseases.
• Cloning is the process of creating a genetically identical copy of an organism.