cells and classification Flashcards
state the MRS GREN processes
movement, respiration, sensitivity, growth, reproduction, excretion, nutrition
define the MRS GREN processes
movement: change in position or change in place
respiration: the chemical reaction that releases energy from food (glucose)
sensitivity: reaction/response to environmental stimuli
growth: increase in size (mass) and is permanent
reproduction: production of offspring
excretion: release of waste substances
nutrition: consuming materials for energy and growth
state: organisms can be classified…….
organisms can be classified into groups by the features they share amongst each other
define the term “species”
a group of organisms that can reproduce to produce fertile offspring
describe the binomial system of naming species
the biological system of naming the organisms in which the name is composed of two terms, the first term indicates the genus, and the second indicates the species of the organism
define classification and the systems aim
the process of sorting items into groups using set criteria. the aim is to reflect evolutionary relationships
state the main features used to place animals and plants into the appropriate kingdoms
Plants: Have cell walls, chloroplasts, and vacuoles
Animals: Cells don’t have cell walls, multi-cellular
Plants: Make their own food, so they are autotrophs
Animals: Consumes food, is heterotrophic
Plants: Can reproduce asexually or sexually
Animals: Have a unique structure for intercellular communication
Plants: have eukaryotic cells with cell walls made of cellulose
Animals: have eukaryotic cells with no cell wall
state the main features used to place organisms into groups within the animal kingdom, limited to the main groups of vertebrates
The symmetry of the body parts along the major body axis, how the organism develops, organisms with similar physical and genetic traits
state the main features used to place all organisms into one of the five kingdoms (5)
cell structure, body organisation, nutrition, reproduction and evolutionary relationships
state the main features used to place organisms into groups within the plant kingdom
cell structure, reproduction, and whether they have seeds or flowers
state the features of viruses
not a living cell, no cell membrane, cannot replicate without the help of a living cell. it is a protein coat (capsid) with genetic material inside (DNA/RNA)
describe and compare the structure of a plant cell with an animal cell
plant cells: regular shape, cellulose cell wall, chloroplasts, nucleus, multicellular, producer
animal cells: irregular shape, no cell wall, nucleus, multicellular, consumer
describe the structure of a bacterial cell
no nucleus (dna naked), peptidoglycan cell wall, single celled, producer & consumer & decomposer
describe the functions of the structures in plant, animal and bacterial cells
Plant cells
cell wall provides structure and protection, it also helps plants maintain their rigid structure.
Chloroplasts contain chlorophyll, a green pigment that captures sunlight energy for photosynthesis.
Vacuoles: Fluid-filled compartments that store cell sap, a solution of salts and sugars.
Animal cells
Cell membrane: Protects the cell from external damage and controls the flow of nutrients, water, and other molecules.
Nucleus: Contains DNA, which controls cell activities such as growth, metabolism, and protein synthesis.
Bacterial cells
cell wall provides structure and protection.
Plasmids: Small circular DNA molecules that are suspended in the cytoplasm.
Binary fission: process that allows bacteria to copy themselves.
state that: new cells are ………
produced by division of existing cells.
state that specialised cells have specific functions, including (7)
ciliated cells, root hair cells, palisade mesophyll cells, neurones, red blood cells, sperm and egg cells
definition of cell
the smallest unit that can live on its own and that makes up all living organisms and the tissues of the body
definition of tissue
A group or layer of cells that work together to perform a specific function
definition of organ
a collection of tissues that structurally form a functional unit specialized to perform a particular function
definition of organ system
a group of organs that work together to perform a specific function in the body
definition of organism
a living thing that can function on its own
state the formula of magnification
magnification = image size/actual size
convert measurements between mm, nm and µm
1mm -> 1µm 1000x -> 1nm 1000x
definition of monocotyledon
single leaf upon germination into a seedling
definition of dicotyledon
first two leaves upon germination
definition of plant
a multi-cellular eukaryote that has a surrounding cell wall made up of cellulose that is autotrophic with the process of photosynthesis
monocotyledon features
parallel leaf veins, ratio of petals in flowers in 3s, scattered vascular bundles in stems (eg grass)
dicotyledon features
branched leaf veins, petal ratio in 5s, vascular bundles arranged around the edge
function of ciliated cells
to push and move mucus from one place to another
function root hair cells
to absorb water and material ions
function palisade mesophyll cells
to carry out photosynthesis
function of neurones
to carry nerve impulses around the body
function of red blood cells
to carry oxygen in the blood
function of sperm cells
to carry genetic information to the egg cell and fertilise it
function of egg cells
to provide all nutrients and organelles for the growth of the early embryo
explain how red blood cells are adapted to carry out its function
filled with a red protein pigment called haemoglobin that carries oxygen, no nucleus so it fits more haemoglobin
explain how nerve cells are adapted to carry out its function
a long fibre (axon) so they can carry messages up and down the body over long distances. it is insulated by a fatty (myelin) sheath that increases the speed
explain how ciliated epithelial cells are adapted to carry out its function
cilia beat in a coordinated wave like pattern that allows smooth movement and has a layer of thin tiny moving hairs (cilia)
explain how sperm cells are adapted to carry out its function
the head contains genetic material for fertilisation, the middle piece has mitochondria to release energy in order to swim, the tail allows the cell to swim
explain how egg cells are adapted to carry out its function
the cytoplasm contains nutrients for the growth of the early embryo and the haploid nucleus contains genetic material for fertilisation
explain how palisade mesophyll cells are adapted to carry out its function
they are tall and packed together to absorb as much sunlight as possible and are packed with chloroplasts for photosynthesis
explain how root hair cells are adapted to carry out its function
they are long and thin so they can penetrate between soil particles and they have a large surface area for water absorption
