life processes

what is a multicellular organism?

an organism made up of many different cells, that are specialised to carry out a particular function

name the 8 life processes.

movement, respiration, sensitivity, growth, reproduction, excretion, nutrition, homeostasis

define the term movement

being able to move in order to obtain the things you need to survive

define the term respiration

the release of energy within cells

define the term sensitivity

being able to respond to your surroundings

define the term growth

an increase in size, mass and number of cells

define the term reproduction

the creation of offspring

define the term excretion

the removal of metabolic waste

define the term nutrition

obtaining food

define the term homeostasis (or control)

control of internal conditions constant within a narrow range

give an example of movement

running

give an example of respiration

break down of glucose

give an example of sensitivity

smell

give an example of growth

a giraffe growing a longer neck

give an example of reproduction

a cat giving birth to a kitten

give an example of excretion

urea, sweat

give an example of nutrition

a human eating a burger

give an example of homeostasis/control

water, glucose, temperature

why would viruses not be classed as living?

they do not respire
they can only reproduce within an organism
do not move
do not sense

why does a microscope have different magnifications?

so that we can make things bigger

why, when using a microscope, do you use a stain?

to make structures visible and to add contrast

name a common stain.

iodine

name four advantages of using a light microscope.

see things you can’t with the naked eye
use with living organisms
relatively easy to use
relatively cheap

name a disadvantage of using a light microscope.

limited magnification

define the term organelle

part of a cell with a particular function

where is most water found in plant cells?

cytoplasm and vacuole

what organelles are found only in plant cells?

cell wall, vacuole, chloroplast

define the term cell

a group of organelles working together to carry out a particular function. A cell is the basic structural unit of living organisms.

define the term tissue

a group of similar cells working together to carry out a particular function

define the term organ

a group of different tissues working together to carry out a particular function

define the term organ system

a group of organs working together to carry out a particular function

define the term organism

a group of organ systems working together to carry out a particular function

name the function of the cell membrane

controls movement of molecules into and out of the cell. Separates the cell from its surroundings.

name the function of the nucleus

contains the DNA and controls the activities of the cell

name the function of the cytoplasm

site of chemical reactions, contains organelles

name the function of the cell wall

made of cellulose to support the cell and allow it to keep its shape

name the function of the mitochondria

site of aerobic respiration

name the function of the vacuole

stores cell sap and helps to support the plant by keeping the cell turgid

name the function of the ribosomes

make proteins

name the function of the chloroplast

contains chlorophyll that absorbs light in photosynthesis

define the term specialised cell

a cell specially adapted to carry out a specific function

how do cells become specialised?

differentiation

what is cell differentiation?

switching on and off genes to make a cell specialised

why are specialised cells so important?

so they can carry out a specific job efficiently

define the term stem cells.

undifferentiated cells which have the ability to develop into a variety of different cells

how do stem cells divide?

mitosis

what is a totipotent stem cell?

can differentiate into all types of cell

what is a pluripotent stem cell?

can differentiate into most types of cell

what is a multipotent stem cell?

can differentiate into some types of cell

what are the three types of stem cells found in the human lifecycle?

embryonic (totipotent), umbilical cord (pluripotent), adult/somatic (multipotent)

why does cell differentiation occur?

to enable cells to specialise to produce new tissues and organs

why is it better to use stem cells from the patient?

same DNA
tissue match
less chance of rejection

for medical treatment are adult or embryonic stem cells better?

embryonic produces a bigger variety of cells, but may ethical issues are involved in their use

where are plant stem cells found?

meristems, in the root tip and shoot tip

what occurs in the meristems?

growth and cell division

give an example of an adult stem cell

bone marrow

what are the disadvantages of adult stem cells?

difficult to extract
difficult to culture
multipotent

what are the advantages of embryonic stem cells?

easier to extract and culture, totipotent

what are the adaptations of the nerve cell/neurone?

long axon, myelin sheath for insulation

state the function of the digestive system

break down large insoluble molecules to smaller, soluble molecules for absorption into the bloof

state the function of the respiratory system

breathing

state the function of the circulatory system

transport materials around the body

state the function of the excretory system

removes metabolic waste

state the function of the nervous system

coordinates the body’s actions

state the function of the endocrine system

produces hormones

state the function of the reproductive system

produces sex cells in males and females and allows the development of the embryo in females