Biology Chapter Overview: Cells and Chemistry

<p>Osmosis (A)</p> Signup and view all the answers

<p>Elastic muscle (B)</p> Signup and view all the answers

<p>Fertilization (C)</p> Signup and view all the answers

<p>To transport oxygen and nutrients throughout the body (A)</p> Signup and view all the answers

<p>Photosynthesis (D)</p> Signup and view all the answers

<p>Sand and water (C)</p> Signup and view all the answers

<p>To exchange gases between the body and the environment (B)</p> Signup and view all the answers

<p>DNA is a double helix structure made up of two polynucleotide chains. Each chain consists of nucleotides, which are composed of deoxyribose sugar, a phosphate group, and a nitrogenous base (adenine, thymine, guanine, or cytosine). The two chains are held together by hydrogen bonds between the nitrogenous bases, with adenine pairing with thymine and guanine pairing with cytosine.</p> Signup and view all the answers

<p>Sex chromosomes are a pair of chromosomes that determine the sex of an individual. In humans, females have two X chromosomes (XX), while males have one X and one Y chromosome (XY). The X chromosome is larger than the Y chromosome and carries genes for various traits, while the Y chromosome is smaller and primarily carries genes related to male sexual development.</p> Signup and view all the answers

<p><strong>Mitosis</strong> is a type of cell division that produces two daughter cells genetically identical to the parent cell. <strong>Meiosis</strong> is a type of cell division that produces four daughter cells, each with half the number of chromosomes as the parent cell. <strong>Mutation</strong> is a permanent change in the DNA sequence of a gene. <strong>Non-disjunction</strong> is the failure of chromosomes to separate properly during cell division.</p> Signup and view all the answers

<p>An atom is composed of a nucleus containing protons (positively charged) and neutrons (no charge), surrounded by negatively charged electrons that orbit the nucleus in specific energy levels called electron shells. Electrons move in a cloud-like region around the nucleus, constantly changing their energy levels and positions.</p> Signup and view all the answers

<p>There are different types of chemical bonding, including:</p> <ul> <li> <strong>Covalent bonding:</strong> Atoms share electrons to form a stable molecule.</li> <li> <strong>Ionic bonding:</strong> Atoms transfer electrons, creating ions with opposite charges that attract each other to form a compound.</li> <li> <strong>Hydrogen bonding:</strong> A type of weak interaction between molecules where a hydrogen atom is attracted to a highly electronegative atom (like oxygen or nitrogen).</li> </ul> Signup and view all the answers

<p>An element is a pure substance consisting of only one type of atom. Each element has a unique atomic number, which represents the number of protons in the nucleus of its atoms. Elements are listed on the periodic table, arranged by atomic number.</p> Signup and view all the answers

<p>Science is a systematic and logical approach to discovering and explaining the natural world through observation, experimentation, and the development of theories and laws.</p> Signup and view all the answers

<p>Biology is the study of living organisms, including their structure, function, growth, evolution, and interactions with their environment.</p> Signup and view all the answers

<p>A hypothesis is a testable statement or proposed explanation for a phenomenon. It is based on limited evidence and requires further investigation to be proven or disproven.</p> Signup and view all the answers

<p>Chemistry is the study of matter and its properties, as well as how matter changes. It can be broadly classified into different branches, including:</p> <ul> <li> <strong>Organic chemistry:</strong> Focuses on compounds containing carbon.</li> <li> <strong>Inorganic chemistry:</strong> Deals with compounds not containing carbon.</li> <li> <strong>Physical chemistry:</strong> Explores the physical properties and behaviors of matter.</li> <li> <strong>Analytical chemistry:</strong> Focuses on identifying and quantifying substances.</li> <li> <strong>Biochemistry:</strong> Examines the chemical processes within living organisms.</li> </ul> Signup and view all the answers

<p><strong>Acidity</strong> refers to the concentration of hydrogen ions (H+) in a solution. Solutions with higher H+ concentrations are more acidic. <strong>Basicity</strong> (or alkalinity) refers to the concentration of hydroxide ions (OH-) in a solution. Solutions with higher OH- concentrations are more basic.</p> Signup and view all the answers

<p><strong>Eukaryotic cells</strong> are complex cells that have a membrane-bound nucleus containing their genetic material (DNA). They also have other membrane-bound organelles, such as mitochondria, endoplasmic reticulum, and Golgi apparatus. <strong>Prokaryotic cells</strong> are simpler cells that lack a membrane-bound nucleus and other membrane-bound organelles. Their DNA is located in a region called the nucleoid. Examples of prokaryotes include bacteria and archaea.</p> Signup and view all the answers

<p>Adenosine triphosphate (ATP) is the primary energy currency of cells. It is a molecule that stores and releases chemical energy for various cellular processes, such as muscle contraction, protein synthesis, and active transport.</p> Signup and view all the answers

<p><strong>Filtration</strong> is the process of separating solids from liquids or gases by passing the mixture through a filter. <strong>Diffusion</strong> is the movement of molecules from a region of high concentration to a region of low concentration. <strong>Osmosis</strong> is the movement of water molecules across a semi-permeable membrane from a region of high water concentration to a region of low water concentration. <strong>Active transport</strong> is the movement of molecules against their concentration gradient, requiring energy input from the cell.</p> Signup and view all the answers

<ul> <li> <strong>Reactant:</strong> A substance that participates in a chemical reaction.</li> <li> <strong>Solution:</strong> A homogeneous mixture of two or more substances.</li> <li> <strong>Precipitate:</strong> A solid that forms from a solution during a chemical reaction.</li> <li> <strong>Product:</strong> A substance that is formed in a chemical reaction.</li> <li> <strong>Compound:</strong> A substance formed by two or more different elements chemically combined in a fixed ratio.</li> <li> <strong>Chemical reaction:</strong> A process that involves the rearrangement of atoms and molecules, resulting in the formation of new substances.</li> </ul> Signup and view all the answers

<p><strong>Homogeneous mixtures</strong> have a uniform composition throughout, meaning that all parts of the mixture have the same properties. Examples include saltwater, air, and sugar dissolved in water. <strong>Heterogeneous mixtures</strong> have a non-uniform composition, meaning that different parts of the mixture have different properties. Examples include sand and water, oil and water, and a salad.</p> Signup and view all the answers

<p>Evolution is the gradual change in the genetic makeup of a population over time. It occurs through natural selection, where individuals with traits that are better suited to their environment are more likely to survive, reproduce, and pass on those traits to their offspring. Over many generations, these favorable traits become more common in the population, leading to the evolution of new species.</p> Signup and view all the answers

<p>Hydrogen bonding is a type of intermolecular force that occurs between molecules containing hydrogen atoms bonded to highly electronegative atoms, such as oxygen or nitrogen. In water (H2O), hydrogen bonds form between the hydrogen atom of one water molecule and the oxygen atom of another water molecule. These bonds are responsible for water's high boiling point and its ability to dissolve many substances. Carbon dioxide (CO2) and carbon monoxide (CO) do not form hydrogen bonds, as they lack hydrogen atoms bonded to highly electronegative atoms.</p> Signup and view all the answers

<ul> <li> <strong>Mass:</strong> The amount of matter in an object.</li> <li> <strong>Weight:</strong> The force of gravity acting on an object.</li> <li> <strong>Density:</strong> The mass of a substance per unit volume.</li> <li> <strong>Solid:</strong> A state of matter with a fixed shape and volume.</li> <li> <strong>Liquid:</strong> A state of matter that has a fixed volume but takes the shape of its container.</li> <li> <strong>Gas:</strong> A state of matter that has no fixed shape or volume and expands to fill its container.</li> <li> <strong>Matter:</strong> Anything that has mass and takes up space.</li> <li> <strong>Mixture:</strong> A combination of two or more substances that are not chemically bonded.</li> </ul> Signup and view all the answers

<p><strong>Bacteria</strong> are single-celled prokaryotes, meaning they lack a nucleus and other membrane-bound organelles. They have a cell wall, a plasma membrane, and cytoplasm. Bacteria can be found in a wide variety of environments, including soil, water, and the human body. Some bacteria are harmful, causing diseases, while others are beneficial, such as those involved in food digestion and the production of antibiotics. <strong>Viruses</strong> are not considered living organisms because they lack the ability to reproduce independently. They consist of genetic material (DNA or RNA) enclosed in a protein coat. Viruses can only replicate by infecting host cells, hijacking their cellular machinery to produce more viruses.</p> Signup and view all the answers

<p>Animal cells are eukaryotic cells that contain a membrane-bound nucleus, cytoplasm, and various organelles. They lack the rigid cell walls found in plant cells. Key organelles include the mitochondria, which generate energy; the endoplasmic reticulum, involved in protein synthesis and lipid metabolism; and the Golgi apparatus, which packages and modifies proteins.</p> Signup and view all the answers

<p>Here's a possible organization from smallest to largest:</p> <ol> <li>Atoms</li> <li>Molecules</li> <li>Organelles</li> <li>Cells</li> <li>Tissues</li> <li>Organs</li> <li>Organ Systems</li> <li>Organism</li> </ol> Signup and view all the answers

<p>These are major organ systems within the human body, working together to maintain life. Here's a brief overview of their functions:</p> <ul> <li> <strong>Skeletal System:</strong> Provides support, protection, and movement.</li> <li> <strong>Muscular System:</strong> Enables movement, posture, and heat generation.</li> <li> <strong>Respiratory System:</strong> Responsible for gas exchange (oxygen intake, carbon dioxide removal).</li> <li> <strong>Cardiovascular System:</strong> Transports oxygen, nutrients, hormones, and removes waste products.</li> <li> <strong>Immune System:</strong> Protects the body from disease-causing organisms.</li> <li> <strong>Integumentary System:</strong> Provides protection, regulates temperature, and senses the environment.</li> <li> <strong>Endocrine System:</strong> Produces and releases hormones that regulate various body functions.</li> <li> <strong>Nervous System:</strong> Processes information, controls actions, and coordinates bodily functions.</li> <li> <strong>Reproductive System:</strong> Enables the production of offspring.</li> <li> <strong>Digestive System:</strong> Breaks down food into nutrients for the body to absorb.</li> </ul> Signup and view all the answers

<p>The cardiovascular system consists of the heart, blood vessels (arteries, veins, and capillaries), and blood. The heart pumps blood through the arteries, carrying oxygen and nutrients to the body's tissues. Deoxygenated blood returns to the heart through the veins, which then pump it to the lungs for oxygenation. Blood flows through the capillaries, where gas exchange occurs with the surrounding tissues.</p> Signup and view all the answers

<p>Blood is composed of several components:</p> <ul> <li> <strong>Plasma:</strong> The liquid portion of blood.</li> <li> <strong>Red blood cells:</strong> Responsible for carrying oxygen.</li> <li> <strong>White blood cells:</strong> Part of the immune system, fighting infections.</li> <li> <strong>Platelets:</strong> Help with blood clotting.</li> </ul> Signup and view all the answers

<p>The main types of blood cells are red blood cells, white blood cells, and platelets.</p> <ul> <li> <strong>Red blood cells (erythrocytes):</strong> Contain hemoglobin, a protein that binds oxygen.</li> <li> <strong>White blood cells (leukocytes):</strong> Part of the immune system, fighting infections. There are various types of white blood cells, each with specific functions.</li> <li> <strong>Platelets (thrombocytes):</strong> Essential for blood clotting, helping stop bleeding from wounds.</li> </ul> Signup and view all the answers

<p>There are three main types of muscle tissue:</p> <ul> <li> <strong>Skeletal muscle:</strong> Attached to bones; responsible for voluntary movement.</li> <li> <strong>Smooth muscle:</strong> Found in internal organs like the stomach, intestines, and blood vessels; responsible for involuntary movement.</li> <li> <strong>Cardiac muscle:</strong> Found only in the heart and responsible for pumping blood through the body.</li> </ul> Signup and view all the answers

<p>Insulin, a hormone produced by the pancreas, helps regulate blood sugar levels. It signals cells to take up glucose from the bloodstream, reducing blood sugar levels.</p> Signup and view all the answers

<ul> <li> <strong>Fertilization:</strong> The process where a sperm cell unites with an egg cell to form a zygote.</li> <li> <strong>Ovulation:</strong> The release of a mature egg cell from an ovary.</li> <li> <strong>Menstruation:</strong> The periodic shedding of the lining of the uterus if fertilization does not occur.</li> </ul> Signup and view all the answers

<ul> <li> <strong>Nose:</strong> The nose is the primary organ involved in the sense of smell and breathing. It filters and warms incoming air.</li> <li> <strong>Mouth:</strong> The mouth is the first part of the digestive system, responsible for chewing (mechanical digestion), tasting, and initiating the breakdown of food.</li> <li> <strong>Hair:</strong> Hair provides insulation, protection, and tactile sensation.</li> <li> <strong>Nails:</strong> Nails protect the fingertips and toes, aiding in fine motor skills.</li> </ul> Signup and view all the answers

<p>Plants can be categorized based on various criteria, including:</p> <ul> <li> <strong>By their vascular system:</strong> <ul> <li> <strong>Vascular plants:</strong> Have specialized tissues for water and nutrient transport (e.g., trees, ferns).</li> <li> <strong>Nonvascular plants:</strong> Lack specialized vascular tissues and rely on diffusion for water and nutrient transport (e.g., mosses, liverworts).</li> </ul> </li> <li> <strong>By their life cycle:</strong> <ul> <li> <strong>Annuals:</strong> Complete their life cycle within a single growing season (e.g., sunflowers, zinnias).</li> <li> <strong>Biennials:</strong> Complete their life cycle over two growing seasons (e.g., carrots, beets).</li> <li> <strong>Perennials:</strong> Live for multiple years, producing flowers and fruits repeatedly (e.g., roses, tulips).</li> </ul> </li> </ul> Signup and view all the answers

<p>Plants absorb water and dissolved nutrients through their roots. Water moves from the soil into the roots through a process called osmosis, driven by a difference in water potential. Once the water reaches the vascular tissues (xylem), it is transported upward to the leaves and other parts of the plant.</p> Signup and view all the answers

<p>Leaves are the primary sites for gas exchange in plants. They have tiny pores called stomata on their surfaces that open and close to regulate gas exchange with the environment. When the stomata are open, carbon dioxide diffuses into the leaf for photosynthesis, and oxygen produced during photosynthesis diffuses out.</p> Signup and view all the answers

<p>Plant cells are eukaryotic cells with several key features:</p> <ul> <li> <strong>Cell Wall:</strong> A rigid outer layer made of cellulose that provides structural support and protection.</li> <li> <strong>Chloroplasts:</strong> Organelles responsible for photosynthesis.</li> <li> <strong>Vacuole:</strong> A large central sac that stores water, nutrients, and waste products.</li> <li> <strong>Other organelles:</strong> Plant cells also contain other organelles, such as mitochondria, endoplasmic reticulum, and Golgi apparatus.</li> </ul> Signup and view all the answers

<p>Cellulose is a complex carbohydrate that is the primary component of plant cell walls. It provides structural support and strength to the cell, allowing plants to maintain their shape and grow upright.</p> Signup and view all the answers

<p>Pollination is the transfer of pollen from the male part of a flower (anther) to the female part (stigma). Pollination can occur by wind, water, or animals, such as insects, birds, or bats. When pollen grains land on the stigma, they germinate and grow a pollen tube, which carries sperm to the ovary, where fertilization can occur.</p> Signup and view all the answers

<ul> <li> <strong>Photosynthesis:</strong> The process by which plants and some algae use sunlight, carbon dioxide, and water to produce glucose (a type of sugar) and oxygen.</li> <li> <strong>Respiration:</strong> The process by which all living organisms, including plants and animals, break down glucose in the presence of oxygen to release energy, carbon dioxide, and water. This energy is used to power cellular processes.</li> </ul> Signup and view all the answers

<p>An ecosystem is a community of living organisms (biotic factors) interacting with their physical environment (abiotic factors). These interactions involve energy flow, nutrient cycling, and relationships between organisms. Ecosystems can range in size from a small pond to a vast forest.</p> Signup and view all the answers