Biology Chapter 1,2,3,4 and 19

diffusion

the net movement of particles from a region of their high concentration to a region of their low concentration along the concentration gradient as a result of random motion

concentration gradient

an imaginary slope from high to low concentration

diffusion in plants

carbon dioxide in through stomata, oxygen out through stomata

diffusion in cells

cytoplasm contains solvents that diffuse through the cell

osmosis

movement of water from a region of high water potential to a region of low water potential across a semipermeable membrane

water potential gradient

difference between water potential of 2 areas

osmosis in animal cells

will burst in pure water, will shrink in a concentrated solution

osmosis in plant cells

will swell but not burst due to the cell wall and become turgid in pure water, will shrink and become flaccid and plasmolysed inside the cell wall in a concentrated solution

active transport

movement of minerals or ions from a region of low concentration to a region of high concentration through a membrane using energy from respiration

carrier proteins

protein molecules in cell membranes that can use energy to change shape and move minerals and ions in and out of the cell

carbohydrates

consist of carbon, hydrogen and oxygen atoms

sugar

simplest and smallest carbohydrate, soluble in water and is sweet

glucose

C6H12O6

glucose in animals

glycogen, energy store

glucose in plants

starch, energy store

test for starch

iodine solution (iodine + potassium iodide, orange brown) turns blue black in the presence of starch

test for reducing sugars

blue benedict's solution turns green then orange-red when heated with reducing sugars

fats and oils

lipids

fats

solid lipids, made from 1 glycerol and 3 fatty acid molecules

oils

liquid lipids

test for fats

shaken in ethanol, then transferred to a test tube with water and form a milky emulsion of bubbles

proteins

made from carbon, hydrogen, oxygen and nitrogen

amino acids

make chains to form proteins, 20 of them

functions of proteins

enzymes, antibodies, haemoglobin, hair and fingernails

test for proteins

blue biurets solution turns violet when in contact with proteins

structure of dna

made of nucleotides that have bases (A bonds with T and C bonds with G)

human pressures

intensive livestock production, habitat destruction, deforestation, non biodegradable plastics

food production

agricultural machinery, chemicals, selective breeding

monocultures

reduction in biodiversity, increase in pests, reduction in soil fertility

greenhouse effect

the heating effect of the trapping of heat by greenhouse gases

greenhouse gases

carbon dioxide and methane

effect of greenhouse gases

sea level rise, more extreme weather events

eutrophication

increased growth of layer of plants on surface of water due to excess nitrates in the water, when these die, bacteria decompose them and respire anaerobically. their large population causes less oxygen in the water for fish causing them to die out

conservation

conservation of forests, fish stocks, endangered species and maintaining genetic diversity

movement

ability to change position or place

respiration

breakdown of glucose to release energy

sensitivity

ability to detect and react to changes in the environment of an organism

growth

permanent increase in size or dry mass

reproduction

process to make more organisms of the same species

excretion

removal of metabolic waste products

nutrition

taking in materials for energy, growth and development

species

group of animals able to reproduce and create a fertile offspring

plant

cells have nucleus and cell wall made from cellulose, cells have chloroplasts

animal

no cell wall, feed on organic matter

fungus

body made of hyphae, decomposers, reproduce through spores

protoctist

mostly unicellular, may/may not have cell walls and chloroplasts

prokaryote

no nucleus, circular loop of dna, peptidoglycan cell walls

vertebrates

have backbone

amphibians

skin no scales, shell less eggs in water, tadpoles - gills, adults - lungs

reptiles

scales, soft shelled eggs

birds

feathers, beak, front 2 limbs are wings, hard shelled eggs

mammals

hair, no eggs - uterus of mother, milk from mammary glands, pinna (ear flap), sweat glands, diaphragm

arthropods

jointed legs

insects

3 pairs of legs, 2 pairs of wings, 1 pair of antennae, body divided into head thorax and abdomen

crustaceans

more than 4 pairs of legs, 2 pairs of antennae

arachnids

4 pairs of legs, no antennae, body divided into cephalothorax and abdomen

myriapods

many legs, segmented bodies, 1 pair of antennae

ferns

have fronds, reproduce by spores produced by sporangia under fronds

dicots

2 cotyledons, taproot, network venation, 4x or 5x petals, regularly arranged vascular bundles

monocots

1 cotyledon, fibrous root, parallel venation, randomly arranged vascular bundles, petals in multiples of 3

virus

take over cells machinery and make copies of itself, kill the host cell

cells

the smallest units from which all organisms are made

cell membrane

thin layer of protein and fats surrounding the cell that is partially permeable, controlling what goes in and out of the cell

cell wall

made of cellulose, freely permeable and helps keep shape of the plant cell

cytoplasm

clear jelly inside the cell, site of metabolic reactions

vacuole

fluid filled space containing cell sap in plant cells

vesicles

small vacuoles in animal cells

nucleus

stores genetic material on chromosomes made from dna

chloroplasts

contain chlorophyll for photosynthesis

mitochondria

site of aerobic respiration to release energy from the breakdown of glucose

ribosomes

small structures that produce protein

bacterial cells

peptidoglycan cell wall, have cytoplasm and ribosomes, no chloroplast and mitochondria, prokaryotic, plasmids - small circles of dna

ciliated cell

found in bronchi, pushes mucus upwards

neurone

found in the nervous system, transmits electrical impulses

red blood cell

found in blood, transports oxygen

sperm

produced in testes, male gamete

egg cell

made in ovaries, female gamete

root hair cell

tips of roots, absorbs water and minerals

palisade mesophyll cells

found in leaves, photosynthesis

plant cell

animal cell

bacterial cell

prokaryote cell

protoctist cell(chlamydomonas)

protoctist cell(paramecium)

virus