bio igcse vocab

movement

an action by an organism or part of an organism causing a change of position or place

respiration

the chemical reactions in cells that break down nutrient molecules and release energy for metabolism

sensitivity

the ability to detect and respond to changes in the internal or external environment

growth

a permanent increase in size and dry mass

reproduction

the processes that make more of the same kind of organism

excretion

the removal of waste products of metabolism and substances in excess of requirements

nutrition

the taking in of materials for energy, growth, and development

cell

basic functional and structural unit in a living organism

tissue

group of cells of similar structure working together to perform the same function

organ

made from different tissues working together to perform specific functions

organ system

group of organs with related functions working together to perform body functions

organism

group of organ systems

diffusion

the net movement of particles from a region of their higher concentration to a region of their lower concentration (i.e., down a concentration gradient), as a result of their random movement

osmosis

the net movement of water molecules from a region of higher water potential (dilute solution) to a region of lower water potential (concentrated solution), through a partially permeable membrane

active transport

the movement of particles through a cell membrane from a region of lower concentration to a region of higher concentration (i.e., against a concentration gradient), using energy from respiration

the importance of active transport

it’s a process of movement of molecules or ions across membranes, including ion uptake by root hairs

carbohydrates

made of carbon, oxygen, and hydrogen

proteins

made of carbon, oxygen, and hydrogen (some have other elements e.g. sulfur)

lipids

made of carbon, oxygen, and hydrogen

glucose test

benedicts solution

starch test

iodine

protein test

biuret solution

lipids test

ethanol

enzymes

proteins that are involved in all metabolic reactions, where they function as biological catalysts

catalysts

speed up the rate of a chemical reaction without being changed or used up in the reaction

photosynthesis

the process by which plants synthesize carbohydrates from raw materials using energy from light

photosynthesis formula

6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂

chlorophyll

a green pigment that is found in chloroplasts that transfers energy from light into energy in chemicals, for the synthesis of carbohydrates

use of starch

an energy store

cellulose

build cell walls

glucose

respiration to provide energy

sucrose

transportation in the phloem

nectar

attract insects for pollination

magnesium ions (function)

needed to make chlorophyll

magnesium ions (deficiency)

causes yellowing between leaves’ veins (chlorosis)

nitrate ions (function)

source of nitrogen needed to make amino acids (to build proteins)

nitrate ions (deficiency)

causes stunted growth and yellowing of leaves

environmental factors on photosynthesis

light intensity, co2 concentration, temperature

wax cuticle

protective layer on top of leaf, prevents water from evaporating

upper epidermis

thin & transparent to allow light to enter palisade mesophyll layer underneath

palisade mesophyll

column shaped cells tightly packed with chloroplasts to absorb more light, maximizing photosynthesis

spongy mesophyll

contains internal air spaces that increases the surface area to volume ratio for the diffusion of gases (mainly carbon dioxide)

lower epidermis

contains guard cells and stomata

guard cells

absorbs and loses water to open and close the stomata to allow carbon dioxide to diffuse in, oxygen to diffuse out

stomata

where gas exchange occurs: opens during day, closes during night, water evaporation also occurs from here. in most plants found in larger concentration on underside of leaf to reduce water loss

vascular bundle

contains xylem and phloem to transport substances to and from the leaf

xylem

transports water into the leaf for mesophyll cells to use in photosynthesis and for transpiration from stomata

phloem

transports sucrose and amino acids around the plant

carbohydrate (food group)

source of energy

proteins (food group)

growth and repair

lipids (food group)

insulation and energy stores

dietary fiber (food group)

provides bulk (roughage) for the intestine to push food through it

vitamins (food group)

needed in small quantities to maintain health

minerals (food group)

needed in small quantities to maintain health

water (food group)

needed for chemical reactions to take place in cells

vitamin c

forms an essential part of collagen protein which makes up skin, hair, gums, and bones

vitamin d

helps the body to absorb calcium so required for strong bones & teeth

calcium

needed for strong bones & teeth and involved in blood clotting

iron

needed to make hemoglobin—the pigment in red blood cells that transports oxygen

scurvy

vitamin c deficiency that results in anemia, spontaneous bleeding, gum ulcerations and tooth loss, pain and swelling in limbs, exhaustion,

rickets

severe lack of vitamin d causing poor bone development

ingestion

the taking of substances, food and drink, into the body

digestion

the breakdown of food

absorption

the movement of nutrients from the intestines into the blood

assimilation

uptake and use of nutrients by cells

egestion

the removal of undigested food from the body as feces

physical digestion

the breakdown of food into smaller pieces without chemical change to the food molecules

chemical digestion

the breakdown of large insoluble molecules into small soluble molecules

amylase

breaks down starch to simple reducing sugars

protease

breaks down protein to amino acids

lipase

breaks down fats and oils to fatty acids and glycerol

bile

an alkaline mixture that neutralizes the acidic mixture of food and gastric juices entering the duodenum from the stomach, to provide a suitable pH for enzyme action in the small intestine

transpiration

the loss of water vapor from leaves

translocation

the movement of sucrose and amino acids in phloem from sources to sinks

sources

the parts of plants that release sucrose or amino acids

sinks

the parts of plants that use or store sucrose or amino acids

the circulatory system

a system of blood vessels with a pump and valves to ensure one-way flow of blood

reducing the risks of heart disease

diet and exercise

risk factors of coronary heart disease

diet, lack of exercise, stress, smoking, genetic predisposition, age, and sex

ways to monitor heart activity

ECG (electrocardiogram), pulse rate, listening to sounds of valves closing

components of blood

red blood cells, white blood cells, platelets and plasma

red blood cells

used for transporting oxygen using hemoglobin

white blood cells

defend the body from pathogens through phagocytosis and antibody production

lymphocytes

antibody production

phagocytes

engulfing pathogens by phagocytosis

platelets

helping blood clot

plasma

the transport of blood cells, ions, nutrients, urea, hormones, and carbon dioxide

blood clotting

preventing blood loss and the entry of pathogens

pathogen

disease carrying organism

transmissible disease

disease in which the pathogen can be passed from one host to another

body defenses against pathogens

skin, hairs in the nose, mucus, stomach acid, white blood cells

controlling spread of disease

a clean water supply, hygienic food preparation, good personal hygiene, waste disposal, sewage treatment

active immunity

defense against a pathogen by antibody production in the body

antibodies

proteins that bind to antigens

herd immunity

if big percentage of population is vaccinated, provides protection for entire population - very few places for the pathogen to breed

aerobic respiration

the chemical reactions in cells that use oxygen to break down nutrient molecules to release energy

aerobic respiration (formula)

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O

anaerobic respiration

the chemical reactions in cells that break down nutrient molecules to release energy without using oxygen

asexual reproduction

a process resulting in genetically identical offspring from one parent

sexual reproduction

a process involving the fusion of the nuclei of two gametes to form a zygote and the production of offspring that are genetically different from each other