Studied by 3 people
what are the 7 characteristics of living organisms?
movement
respiration
sensitivity
growth
reproduction
excretion
nutrition
MRS GREN
what is movement?
an action by an organism or part of an organism causing a change in position or place
what is respiration?
the chemical reactions that break down nutrient molecules in living cells to release energy for metabolism
what is sensitivity?
the ability to detect or sense stimuli in the internal or external environment and to make appropriate responses
what is growth?
a permanent increase in size and dry mass by an increase in cell number or cell size or both
what is reproduction?
the process that makes more of the same kind of organism
what is excretion?
the removal from organisms of toxic materials, the waste products of metabolism (chemical reactions in cells including respiration) and substances in excess of requirements
what is nutrition
the taking in of materials for energy, growth, and development; plants require light, carbon dioxide, water, and ions; animals need organic compounds, ions, and usually need water
____ and ___ cells are multicellular, contain a nucleus w a distinct membrane.
animal and plant
animal cells do not have a ________
cellulose cell wall
animal cells do not contain _____
chloroplasts
animal cells often store carbohydrates as _____
glycogen
Do animal cells have nervous coordination? (yes or no answer)
yes
are animal cells able to move from place to place? (yes or no answer)
yes
what cell is this?
animal cell
____ have a cell wall made out of XXX
plant cells
cellulose
plant cells contain ____ so that they can carry out photosynthesis
chloroplasts
plant cells store carbohydrates as what?
starch or sucrose
do plant cells have nervous coordination?
no
what cell is this?
plant cell
what is the function of the nucleus?
contains the DNA which controls the activities of the cell
what is the function of the cytoplasm?
its a gel like substance that supports the internal cell structures. Its also the site of many chemical reactions
what is the function of the cell membrane?
it holds the cell together as well as controls which substances can enter and leave the cell
what is the function of the ribosomes?
they are the sites of protein synthesis
what is the function of the mitochondria?
it is the site of most of the chemical reactions involved in respiration, where energy is released to fuel cellular processes.
what is the function of the cell wall?
it gives the cell extra support, defining its shape
what is the function of the chloroplasts?
it contains chlorophyll and the enzymes needed for photosynthesis
what is the function of the vacuole?
it is used for storage of certain materials and it also helps support the shape of the cell
do animal cells have a cell wall?
no
how are new cells produced?
through the division of existing cells
what are specialised cells?
they are cells which have developed certain characteristics in order to perform particular functions.
what is differentiation?
it is when cells develop the structure and characteristics needed to carry out their functions
what is the function of a ciliated cell?
to move the mucus in the trachea and bronchi
what is the adaptation of a ciliated cell?
extension of the cytoplasm at the surface of the cell to form hair-like structure called cilia which beat to move mucus up to the throat
what is the function of a nerve cell?
the conduction of impulses
what are the adaptations of a nerve cell? (3)
long so that nerves can run to and from diff places of the body to the CNS
has extensions and branches so that it can communicate w other nerve cells
the axon is covered w a fatty sheath which insulated the nerve and speeds up the nerve impulse
what is the axon?
it is an extension of cytoplasm away from the cell body
what is the function of a red blood cell?
to transport oxygen
what are the adaptations of the red blood cell? (3)
biconcave disc shape increases the surface area for more efficient diffusion of oxygen
contains haemoglobin which joins w oxygen to transport it
contains no nucleus to increase amount of space available for haemoglobin
what is the function of the sperm cell?
reproduction
what are the adaptations of the sperm cell? (4)
the head contains genetic materials for fertilisation in a haploid nucleus.
the acrosome in the head contains digestive enzymes so that a sperm can penetrate the egg
the mid-piece is packed w mitochondria to release energy needed to swim and fertilise the egg
the tail enables to sperm to swim
how many chromosomes are in a haploid nucleus?
23
what is the function of the egg cell?
reproduction
what are the adaptations of the egg cell? (3)
contains a lot of cytoplasm which has nutrients for the growth of the early embryo
haploid nucleus contains the genetic material for fertilisation
cell membrane changes after fertilisation by a single sperm so that no more sperm can enter
what is the function of a root hair cell?
absorption of water and mineral ions from soil
what are the adaptations of a root hair cell? (3)
root hair increases surface area of cell to ensure maximum absorption of water and mineral ions
walls are thin to ensure water moves through quickly
no chloroplasts present
what is the function of a xylem vessel?
conduction of water through the plant; support of the plant
what are the adaptations of a xylem vessel? (3)
no top and bottom walls between xylem vessels so there is a continuous column of water running through them
cells are dead w/o organelles or cytoplasm to allow free passage of water
their wall become thickened w a substance called lignin when means they are able to help support the plant
what is he function of the palisade mesophyll cell?
photosynthesis
what are the adaptations of the palisade mesophyll cell? (2)
column shaped to maximise absorption of sunlight and fit as many in a layer under the upper epidermis of the leaf as possible
contains many chloroplasts for maximum photosynthesis
what is the formula for magnification?
Magnification = image size x actual size
what is the formula for actual size?
Actual size = Image size / magnification
what is the formula for image size?
Image size = actual size x magnification
Note
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