Biology grade 11

Nucleotide

The repeating unit of DNA consisting of deoxyribose sugars, a phosphate group, and one of four nitrogenous bases.

Complementary Base Pairing

The pairing of nitrogenous bases in DNA where adenine (A) pairs with thymine (T) and guanine (G) pairs with cytosine (C).

Chromosomes

Structures containing DNA, including haploids (n = 23 chromosomes) and diploids (2n = 46 chromosomes).

Homologous Chromosomes

Chromosome pairs with alleles carrying the same genes, inherited maternally and paternally.

Mitosis

Asexual cell division process resulting in two identical daughter cells, involving prophase, metaphase, anaphase, and telophase.

Meiosis

Cell division in sexually reproducing organisms reducing chromosome number in gametes, with two divisions halving the chromosome number.

Karyotype

Complete set of an individual's chromosomes arranged by size.

Non-Disjunction

Failure of chromosomes to separate during cell division, leading to abnormal chromosome numbers.

Gregor Mendel

Biologist known for experiments with peas, establishing genetic principles.

Alleles, Genotypes, Phenotypes

Alleles are gene forms on chromosomes, genotypes are genetic makeup, and phenotypes are observable traits influenced by both genotype and environment.

Complete Dominance

Condition where dominant allele masks the recessive allele's effect on phenotype.

Co-Dominance

Inheritance where two alleles of a gene are expressed separately, influencing the phenotype.

Sex-Linked Inheritance

Alleles found on sex chromosomes (X or Y) affecting inheritance patterns.

Organelles

Membrane-bound structures in cells like nucleus, ribosomes, endoplasmic reticulum, Golgi apparatus, lysosomes, mitochondria, vacuoles, and chloroplasts.

Hierarchy of Cells to Organisms

Organelles -> Cells -> Tissues -> Organs -> Organ systems -> Organisms.

Blood Components

Blood is composed of plasma, red blood cells, white blood cells, and platelets, with plasma making up 55%, blood cells 45%, and white blood cells and platelets less than 1%.

Pulmonary Artery/Vein

The pulmonary artery carries oxygen-poor blood from the heart to the lungs, while the pulmonary vein carries oxygen-rich blood from the lungs to the heart.

Aorta

The aorta is the main artery that carries blood away from the heart to the rest of the body.

Sinoatrial Node

The SA node generates an electrical signal causing the atria to contract, acting as the pacemaker of the heart.

Veins

Veins transport blood at lower pressure, have valves to keep blood flowing toward the heart, and receive blood from capillaries.

Arteries

Arteries withstand high pressure due to thick walls, branch from the aorta, and transport blood from the heart.

Capillaries

Capillaries facilitate the exchange of O2 and CO2 due to their thin walls, allowing blood cells to pass through in a single file line.

Pathway of Blood

Describes the flow of deoxygenated and oxygenated blood through the heart and lungs.

Cardiac Output

The product of heart rate and stroke volume, measured in liters per minute.

Respiratory System Components

Describes the structures and functions of components like the nasal cavity, trachea, and lungs.

Mechanisms of Breathing

Explains how the diaphragm and intercostal muscles control inhalation and exhalation based on pressure and volume changes.

Smoking

Smoking can cause lung diseases like COPD and lung cancer by damaging airways and alveoli.

Asthma

Chronic lung disease characterized by inflammation and muscle tightening around the airways, treated with inhalers.

Macromolecules

Organic compounds made of carbon and hydrogen, including proteins, lipids, nucleic acids, and carbohydrates like monosaccharides and polysaccharides.

Lipids

Fats used for insulation, energy storage, hormone production, organ cushioning, and cell membrane building. Fat stores more energy than carbs, with 1g of fat = 9 calories and 1g of carbs = 4 calories.

Protein

Acts as enzymes, transports materials, acts as hormones, and is a key component in various body parts. Made up of amino acids, with 20 different types required by humans.

Monomer

Single organic compound used to make a polymer.

Polymer

Chain of multiple monomers.

Polymerization

Process of chaining monomers to form a polymer.

Path of Food Along the System

Mouth, Esophagus, Stomach, Small Intestine, Large Intestine.

Lactose Intolerance

Insufficient lactase enzyme in the small intestine leading to the inability to digest lactose.

Diseases Affecting the Digestive System

H. pylori causing ulcers, treated with antibiotics and proton pump inhibitors. Diarrhea is loose, watery stools.

Genetic Diversity

Unique genetic combinations inherited from parents, leading to variations in traits.

Commensalism

Interaction where one species benefits and the other is unaffected.

Mutualism

Interaction where both species benefit.

Parasitism

Interaction where one species benefits and the other is harmed.

Structural Diversity

Range of physical sizes, shapes, and distributions in ecosystems.

Binomial Nomenclature

Naming system with genus and species names.

Antibiotics

Substances used to kill bacteria, leading to potential resistance.

Natural Selection

Process of adaptation to the environment, leading to survival of individuals with ideal traits.

Adaptations

Changes in animals to cope with environmental changes.

Speciation

Formation of new species through reproductive isolation mechanisms.

Divergent Evolution

Interbreeding species diverging into different groups.

Plant Tissue

Dermal, Vascular, Ground, and Meristematic tissues in plants.

Meristems

Center of active mitotic cell division in plants where growth occurs, found in root tips, shoots, buds, and areas of new growth.

Xylem and Phloem

Xylem transports water and minerals upward, while phloem carries food downward in plants.

Transport

Movement of substances in plants from source (high sugar concentration) to sink (low sugar concentration), influenced by seasons and fruit development.

Capillary Action

Water movement upward in plants due to adhesion properties being stronger than cohesion properties.

Seed Structure

Consists of embryo (tiny plant), endosperm (nutritive tissue), and seed coat (protective layer).

Structures & Functions of Leaves, Stems, and Roots

Internal structures like cuticle, epidermis, palisade, spongy layer, stomata, cortex, cambium, phloem, xylem, pith, and their functions.

Leaf Specializations

Unique leaf adaptations like Venus flytraps for trapping insects and cactus spines.

Asexual Plant Reproduction

Methods like runners, tubers, leaves, roots, and grafting for producing genetically identical clones.

Types of Tropisms

Phototropism (growth towards light), Gravitropism (shoots up, roots down in response to gravity), Thigmotropism (response to touch stimulus).