form 1 science Flashcards
what is science?
science is a discipline that involves systematic observations and experiments on natural phenomena
list 2 importance of science in everyday life
for medical research OR faster, safer and more comfortable OR invention of communication tools
list ALL of the apparatus used in science lab
test tube, boiling tube, beaker, conical flask, round bottom flask, flat bottom flask, gas jar, bell jar, measuring cylinder, burrete, pippete, filter funnel, evaportaing dish, bunsen burner, crucible, test tube holder, wire gauze, tripod stand
list all of the hazards symbols
explosive, flammable, toxic or poisonous, corrosive, irritant, radioactive
examples of explosive hazard
potassium, sodium, lithium and hydrogen gas
examples of flammable hazard
phosphorus, alcohol and petrol
examples of toxic or poisonous hazard
mercury, cyanide, lead and chlorine
examples of corrosive hazard
concentrated acids and alkalis
examples of irritant hazard
chloroform, ammonia, iodine, and chloride
examples of radioactive hazard
uranium, plutonium, radium and thorium
definition of length
distance between two points
definition of mass
the quantity of matter
definition of time
measured period between two moments
definition of temperature [Kelvin(K)]
measure of how hot or cold an object is
1C= 274.15 K
defintion of electrical charges
electrical current is defined as the rate of flow of charges(electrons) through a conductor
definition of volume
amount of space occupied by an object
definition of error
difference between the measure value and actual value of a quantity
definiton of systematic error
errors caused by faulty instruments or changes in the environmental during measurement
read chapter 1
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definition of density
density of a substance is the mass per unit volume of the substance
formula of density
mass/volume
read abt density
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list the scientific investigation in order
identifying the problem , forming hypothesis , controlling variables , planning an experiment , carrying out experiment , collecting data , analysing and intepreting data , making conclusion , writing report
definition of cell
a cell is a basic unit that makes up all living things
explain how cancer can be formed
when cells divide rapidly without control
how does a tumor formed?
if the cells are not destroyed, cancer cell will divide uncontrollably and form a tumour, an abnormal lump of cells
read abt microscope pg 30
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list all 4 structures in animal cell
cell membrane, nucleus, cytoplasm and mitochondria
list all 7 structures in plant cell
cell membrane, nucleus, cytoplasm, mitochondria , vacuole, cell wall and chloroplast
list 2 difference between animal and plant cell
- animal cell does not have cell wall where else, plant cell has a cell wall made of cellulose
2, animal cell does not have chloroplast where else plant cell has chloroplasts that contains chlorophyll - animal cell has no fix shape where else plant cell does
definiton of unicellular organisms
organisms that contains only one cell
definition of multicellular
organsims that consist of more than one cell
examples of unicellular animals
amoeba and paramecium
examples of unicellular plants
yeast and chalamydomonas
what unicellular organisms can be classified as plant and animal
euglena (can make food in the presence of sunlight and can feed and move by using flagella
examples of multicellular animals
mammals, reptiles, amphibians, birds and fish
examples of multicellular plants
algae, ferns and most of flowering plants
definition of specialised cells
cells that have become differentiated to carry out a particular function
functions of nerve cells
carry informations in the form of nerve impulses to different parts of the body
characteristics of nerve cells
known as neurons and has long, thin fibres
functions of red blood cells
transports oxygen from lungs to whole body and transport carbon dioxide from the body cells back to the lungs which is then expelled during exhalation
functions of muscle cell
produce movements
what does red blood cell contain?
haemoglobins which combine with oxygen AND biconcave disc shape which provides a large surface area
what are haemoglobins
red pigments
where does elongated muscle cells exists at?
the wall of the intestine
whrere does branched shape muscle cells exixts at?
in the heart (cardiac muscle)
functions of epithelial cells
cover outerspace of body and line surface of organs
functions of white blood cells
destroy bacteria and protect the body against diseases
does white blood cell have a fixed shape?
no
list two types of reproductive cells
sperm and ovum
list 4 types of specialised plants cell
epidermal cells, palisade cells, root hair cells and guard cells
state the way of formation of an organism
cell, tissue, organ, system and multicellular organism
list 12 types of systems
blood circulatory system, respiratory system, digestive system, excretory system, integumentary system, muscular system, skeletal system, lympathic system, nervous system, endrocrine system and reproductive system.
functions of blood circulatory system
transport respiratory gases, nutrients, hormones and waste products.
functions of respiratory system
absorbs oxygen and releases carbon dioxide
functions of digestive system
breaks down complex food into smaller form so that nutrients can be easily absorbed by the body
functions of excretory system
removes excretory products
functions of integumentary system
protects the body from infection and keeps the body from losing water excessively(dehydration)
functions of muscular system
assists human in movements
functions of skeletal system
provides support and protects internal organs
functions of lympathic system
defends the body against infections
functions of nervous system
carries nerve impulses and coordinates all body activities
functions of endocrine system
secretes hormones
functions of reproductive system
produces sperm cells, ova and hormones to produce offspring
definition of external breathing
exchange of oxygen and carbon dioxide between an organism and its environment
definition of cellular respiration
body cells are able to break down the food to release energy
definition of photosynthesis
green plants make food from carbon dioxide and water in the presence of light and chlorophyll
products of photosynthesis
glucose and oxygen
where is excess glucose stored and in what form?
leaves, stems, fruits and roots in the form of starch
what test can be used to determine whether photosynthesis has taken place?
iodine test
importance of cellular respiration and photosynthesis
survival of living things OR maintaining the balance of oxygen and carbon dioxide in the atmosphere
list two differences between cellular respiration and photosynthesis
- cellular respiration occurs in all the living things where else, photosynthesis occurs in all the plant cells that contain chlorophyll.
- cellular respiration is a process of breaking down food, where else photosynthesis is the process of making food.
- cellular respiration takes place in mitochondria, where else photosynthesis takes place in chloroplasts.
- cellular respiration releases water and carbon dioxide, where else, photosynthesis uses water and carbon dioxide.
- cellular respiration uses oxygen, where else, photosynthesis releases oxygen.
- cellular respiration occurs all the time, where else photosynthesis occurs only in the presence of light.
- cellular respiration releases energy during the break down of food, where else, photosynthesis absorbs light energy to make food.
where does cellular respiration take place?
takes place in mitochondria
where does photosynthesis takes place?
takes place in chloroplasts.
definition of homeostasis
process of regulating the internal environment of the body to be in a balanced and stable condition
when does homeostasis occurs in the body?
when the internal environment of an organism changes
what temperature must our body maintain constantly?
37 degree Celsius
what will happen if extra 6 degree Celsius will do to the body?
affect the functions of body cells and this can cause death
what systems are involved in the regulation of water content?
excretory system and endocrine system.
what pulse rate is considered as normal?
60 to 90
how does plant lose water to the surrounding?
transpiration process
what is transpiration?
process of losing water from the surface of plants leaves in form of water vapour to the atmosphere through stomata
what is stoma?
stoma is a tiny pore on the surface of leaf and is used for gas exchange and absorption of water vapour
when does stoma open?
during the day
why does stoma open?
to allow gas exchange and releases water vapour
wen does stoma closes?
during a very HOT day.
why is stoma closed?
to reduce the water loss through transpiration. the leaf wilts under hot sun.
why do we urinate often during a rainy day?
we do not sweat a lot on a rainy day. therefore, the excess water in the body will be removed from the body through urine.
what is the corrective mechanism that will occur when our body temperature drops? explain.
- blood vessels constrict
- sweat less
- hairs stand erect
- skeletal muscles will contract and relax actively
- hormones will be secreted to increase body metabolism
why do dogs always tick out their tongue?
they allow saliva to evaporate from tongue to reduce body temperature.
