Comprehensive Biology Review Flashcards

Flashcards generated from lecture notes to aid in exam preparation.

Organelles

Specialized subcellular structures found within living cells.

Cells

Basic structural unit of a living organism.

Tissues

Group of cells with similar structures, working together to perform the same function.

Organs

Group of tissues, working together to perform specific functions.

Organ Systems

Group of organs with similar functions, working together to perform body functions.

Nucleus

Contains the genetic material, which codes for a particular protein; enclosed in a nuclear membrane.

Cytoplasm

Liquid substance in which chemical reactions occur; contains enzymes.

Cell membrane

Contain receptor molecules to identify and selectively control what enters and leaves the cell.

Mitochondria

Where aerobic respiration reactions occur, providing energy for the cell.

Ribosomes

Where protein synthesis occurs.

Chloroplasts

Where photosynthesis takes place, providing food for the plant; contains chlorophyll pigment.

Permanent vacuole

Contains cell sap; improves cell’s rigidity.

Cell wall

Made from cellulose; provides strength to the cell.

Specialized cells

Cells that have developed certain characteristics in order to perform particular functions.

Cell differentiation

A process that involves the cell gaining new sub-cellular structures in order for it to be suited to its role.

Sperm cells Specializations

Streamlined head and long tail to aid swimming, many mitochondria provide energy, acrosome has digestive enzymes.

Nerve cells Specializations

Long axon for carrying impulses, dendrites for branched connections, nerve endings with mitochondria for neurotransmitters.

Muscle cells Specializations

Special proteins for contraction, lots of mitochondria for energy, can store glycogen.

Root hair cells Specializations

Large surface area due to root hairs, large permanent vacuole, mitochondria for active transport of mineral ions.

Xylem cells Specializations

Lignin deposition causes cells to die and become hollow, forming a continuous tube for water and mineral ion transport.

Phloem cells Specializations

Cell walls form sieve plates, energy is supplied by companion cells.

Stem cell

An undifferentiated cell which can undergo division to produce many more similar cells that can differentiate.

Meristems in plants

Found in root and shoot tips; can differentiate into any type of cell throughout the life of the plant.

Carbohydrates

Made of carbon, oxygen, and hydrogen; polymers that break down into simple sugars.

Proteins

Made of carbon, oxygen, hydrogen, sulfur, nitrogen, and phosphorus; polymers that can be broken down into amino acids.

Lipids (fats and oils)

Made of carbon, oxygen, and hydrogen; large polymers that can be broken down into 3 fatty acid molecules and a glycerol molecule.

Benedict’s solution test for glucose

Turns brick red if glucose is present; remains blue if not.

Iodine solution test for starch

Turns blue-black if starch is present; remains brown if not.

Biuret solution test for protein

Turns purple if protein is present; remains blue if not.

Ethanol and distilled water test for fat

A milky white emulsion forms if fat is present; remains colorless if not.

Enzymes

Biological catalysts that increase the rate of reaction without being used up.

Lock and Key Hypothesis

The shape of the substrate is complementary to the shape of the active site, forming an enzyme-substrate complex.

Factors affecting enzyme activity

Enzyme activity is affected by changes in temperature and pH due to denaturation.

Diffusion

The spreading out of particles resulting in a net movement from an area of higher concentration to an area of lower concentration.

Osmosis

The movement of water from a less concentrated solution to a more concentrated solution through a partially permeable membrane.

Active transport

The movement of particles from an area of lower concentration to an area of higher concentration, requiring energy.

Photosynthesis

The process of making glucose from sunlight in the leaves of the plant.

Waxy cuticle

Helps to reduce water loss by evaporation.

Upper epidermis

Very thin and transparent in order to let light in to the palisade mesophyll.

Palisade mesophyll

Contain lots of chloroplasts so that photosynthesis can happen rapidly.

Spongy mesophyll

Have lots of air spaces to allow gases to diffuse in and out of cells faster.

Lower epidermis

Contains guard cells and stomata.

Guard cell

Kidney-shaped cells that open and close the stomata.

Stomata

Where gas exchange and loss of water by evaporation takes place.

Magnesium

Required for chlorophyll production; deficiency causes leaves to turn yellow.

Nitrate

Required to produce amino acids; deficiency causes stunted growth and turns leaves yellow.

Balanced diet

Maintain health; should consist of carbohydrates, proteins, lipids, dietary fibre, vitamins, minerals and water.

Mouth in alimentary canal

Mechanical digestion breaks food into smaller pieces; chemical digestion uses amylase to break down starch.

Oesophagus

Tube from the mouth to the stomach; food bolus moves down due to peristalsis.

Pancreas

Produces carbohydrase, protease and lipase enzymes which it secretes into the stomach and small intestine.

Stomach

Releases gastric juice (pepsin and hydrochloric acid) to break down proteins and kill bacteria.

Duodenum

Carbohydrases, proteases and lipases digest food here; bile is released to emulsify fats and neutralize acid.

Ileum

Lined with villi to maximize absorption of digested soluble molecules into blood.

Large intestine

Water is absorbed to produce faeces; faeces is stored in the rectum.

Carbohydrates

Broken down by carbohydrases into simple sugars like glucose.

Proteins

Broken down by proteases into amino acids.

Lipids

Broken down by lipases into glycerol and 3 fatty acids.

Energy transferred (J) calculation

Temperature increase (°C) x mass of water (g) x 4.2 (J/g°C).

Respiration

Occurs in every cell in the body to supply ATP.

Aerobic respiration

Uses oxygen; yields the most energy; occurs in the mitochondria.

Anaerobic respiration

Occurs when there is not enough oxygen; does not yield as much energy; oxidation of glucose is incomplete.

Adaptations of leaves for gas exchange

Spongy mesophyll, guard cell, stomata, thin leaves, flattened shape.

Ribs

Muscle ‘cage’ surrounding the lungs to provide protection of internal organs.

Intercostal muscle

Muscles found between the ribs that control inhalation and exhalation.

Diaphragm

Muscular dome at the bottom of the thorax that changes the pressure in order to control inhalation and exhalation.

Trachea

The windpipe, where air enters the thorax and flows to the lungs.

Bronchi

The trachea divides into 2 of these.

Bronchioles

The bronchi further divide into smaller tubes that connect to the alveoli.

Alveoli

Tiny air sacs where gas exchange occurs.

Pleural membranes

Found on the outside of the lungs and inside of chest cavity to lubricate the lungs.

Alveoli adaptations

Thin cell walls, folded shape, large network of tiny capillaries.

Phloem adaptations

Transport sucrose and amino acids between leaves and other parts of the plants (translocation).

Xylem adaptations

Water travels up the xylem from the roots into the leaves, lignin strengthens the plant.

Transpiration

Evaporation of water from the surface of a plant; consequence of gaseous exchange.

Water absorption

Taken up by plants through root hair cells via osmosis.

Factors affecting transpiration

Factor: Increase in light intensity. Effect: Increases rate of photosynthesis, increased rate of transpiration.

Factors affecting transpiration

Factor: Increase in temperature. Effect: Water molecules move faster, increased rate of transpiration.

Factors affecting transpiration

Factor: Increased air movement (wind). Effect: Steeper concentration gradient, increased rate of transpiration.

Factors affecting transpiration

Factor: Increase in humidity . Effect: Reduced concentration gradient, decreased rate of transpiration.

Plasma

The liquid which carries the components in the blood.

Red blood cells

Carry oxygen molecules from the lungs to all the cells in the body.

White blood cells

Part of the immune system, which is the body’s defence against pathogens.

Platelets

Stop bleeding and form a clot.

Platelets

Cause fibrinogen proteins to form a mesh of insoluble fibrin across the wound, trapping red blood cells and therefore forming a clot.

Vaccinations

Contain either a dead or inactivated form of the pathogen to stimulate white blood cells to produce antibodies.

Circulatory system

Carries oxygen and nutrients to every cell in the body and removes any waste products.

Heart structure

Made up of muscular walls, has 4 chambers that separate the oxygenated blood from the deoxygenated blood, coronary arteries supply it with blood.

Arteries

Carry blood AWAY from the heart; have strong, elastic walls to withstand high pressure.

Veins

Carry blood TOWARDS the heart; have wide lumen and valves to ensure blood flows in the right direction.

Capillaries

Allow the blood to flow very close to cells to enable exchange of substances; have thin, permeable walls.

Adrenaline

Is a hormone produced by the adrenal glands above the kidney and increases the heart rate to deliver more oxygen to respiring muscles.

Coronary arteries

Supply blood to the heart and become blocked in CHD due to a build-up of fatty plaques.

Roles of the kidney

Maintain the balance of water and other substances in the body through filtration, selective reabsorption, osmoregulation, and excretion.

ADH function

Anti-diuretic hormone (ADH) is released by the pituitary gland and increases the kidney tubules permeability to water.

Homeostasis

Maintenance of a constant internal environment.

Tropisms in plants

The response to light and gravity, coordinated and controlled by hormones.

Nervous system

Made up of nerve cells that carry impulses around the body.

Endocrine system

Made up of glands that produce hormones that stimulate changes in the body.

CNS

Consists of the brain and the spinal cord.

Synapses

The gap between two neurons and transmission of impulses across it are chemical and uses neurotransmitters.