Science Notes Form 4

 

Summary Notes for Science

 

Form 4 Chapter 1 Scientific method

a phenomenon Observing a phenomenon

the problem Identifying the problem

Makina a hypothesis

Planning the investigation

Conducting the experiment

Collecting data

Analyzing and interpreting data

Making a conclusion

     

先观察（observing）事项（ phenomenon） 识别（identifying）问题（ problem） 根据上面所观察的 phenomenon 找出问题 列出假设（hypothesis） !he"the# !he"the 策划（ planning）调查（investigation） 策划调查 hypothesis 对不对 conducting）实（experiment） 根据所策划的 investigation !" experiment 做出（collecting #$（ ）%据（data） & experiment '()#$所*+的%据

 



,-（analyzing）./0（interpreting）%据（data） 根据所#$的 data 做出 Analyzing $ Interpreting Analyzing 12（Conclusion） 3据 所4 data ,-56列出的 hypothesis 789:

 

Form4 Chapter 2  %ody coordination

Nervous System ( ; )

Central Nervous System • •

Brain & Spinal cord ( ?@ ) Control the centre of nervous

system

 &eurones

Peripheral Nervous System • Consists of nerves emerging from the brain and the spinal cord (Cranical nerves and Spinal nerves) • Lin receptors and e!ectors "ith CNS

 

Sensory Neurone # Send nerve impulses from sensory organ $ receptors to CNS

%elay Neurone $ &nterneurone # sends impulses from sensory neurone to motor neurone'

otor Neurone # %eceive nerve impulses from relay neurone and send to e!ector

Structure of a neurone 'endrite ( receive impulse from other neurone 'endron ( transmit impulses from dendrite to cell body Cell bosy ( control all cell activities Axon ( transmit impulses out of cell bodu Myelin shealth (  to ensure the impulses transferred in one direction d irection  

 to speed up transmission

!erminal !erminal dendrite ( transmit impulses to dendrite of other ne neurone urone

Path)ay of &ervous Impulses *eceptor

*eflex Action

Sensory neurone

C&S

Motor &eurone

+ffector 

 

 

Involuntary action , does not go through brain -ast

*eflex Arc ( Stimulus

 

%ecepto r

Sensory neurone

 

Synapse

 

%elay Neurone

 

synapse

 

(otor neurone

 

)!ector

 

%espons e

Proprioceptor    

A.k.a Strentch receptor  -ound in muscle# tendons# ligaments# /oints -untion ( maintain body balance $ coordination   Coordinate movements and make us a)are of our position

%rain Cerebrum0A的1 ( control voluntary action Cerebellum0B的1 ( Maintain body coordination $ maintain body balance Medulla Oblongata ( Controls involuntary action

 Endocrine System System (hormonal) +ndocrine 2land Pituitary 2land !hyroid 2land Pancreas Adrenal 2land Ovary !estis

3ormone 2ro)th 3ormone

-unction Master gland

!hyroxine

promotes gro)th control metabolism rate

Insulin Adrenaline Progestrone $ Oestrogen !estrosterone

stimulate gro)th Control blood sugar level increase heartbeat -emale secondary sexual development Male secondary sexual development

 

Form 4 Chapter 3 Mitosis ( 1.  4.  5. 6.  7. 

Chromosome  Chromosome thicken and shorten Replication take place Replication take Chromosome arrange  at the equatorial plate of arrange at plate of the cell Chromatids move Chromatids  move and  and divide divide to  to opposite poles of poles of the cell# the cell start to separate to separate Two Two daughter cells produced cells produced

Meiosis ( 8. 4. 5. 6.  7.  9. 7.  8. 

Chromosome thicken Chromosome  thicken and  and shorten  shorten  Replication $  Replication  $ crossing over  take  take place Chromosome arrange arrange at  at the equatorial plate of plate of the cell Chromatids move Chromatids  move and  and seperate  seperate to  to opposite poles of poles of the cell# the cell start to divide Two Two daughter cells produced cells produced Chromosome arrange arrange at  at the equatorial plate of plate of the cell Chromatids  Chromatids separate and  separate and cells start to divide Four    daughter cells are cells are produced

Place occurs Cell division 'aughter cells 2enetic contents of daughter cell  &o. of Chromosome Crossing :ariation over 

Mitosis

Meiosis

Som Somat atiic cceell llss-rroots a and nd shoo shoott tip tipss

Rep eprroduc ductive tive cell cellss in in ov ovary ary tteesti stis

1

!

!

"

Same as parental cell

#i$$erent $rom parental cell  

Same num%er as parental cell

&al$ num%er o$ parental cell  

 'o

(es (es

 'o

(es (es

 

-unctions

-)roduce new cells $or growth and replace

-)roduce gamete $or se*ual 

damaged cells

reproductions ensure that the chromosome num%er num%er o$ a species is maintained

Sex determination ( Male ; 8 ovum# 8 sperm# 8 placenta  'on-identical Twins Twins (  ( 4 ova# 4 sperm# 4 placenta ???Siamese !)ins CDE

Mutation Chromosome Mutation ( 8. 'o)n@s 'o)n@s syndrome syndrome  extra extra chromosom chromosomee 48# total chromos chromosome ome 6 instead instead of usual usual 69 4. Blinefelter@ Blinefelter@ss syndrome syndrome ,