TELEMATICS 2019 LIFE SCIENCES Grade 12 · Life Sciences Telematics resource Grade 12 2019 2 ... For...

Directorate: Curriculum FET

TELEMATICS 2019

LIFE SCIENCES

Grade 12

LIFE SCIENCES PROGRAMME FOR GRADE 12:

Life Sciences Telematics resource Grade 12 2019

2

Date Time Topics

18 February 2019 16h00 – 17H00 Scientific investigations, Protein synthesis, mutations

04 March 2019 15h00 – 16h00 Meiosis 15 April 2019 16h00 – 17h00 Senses and homeostasis

22 July 2019 15H00 – 16h00 Natural selection, Punctuated equilibrium and speciation

1. TIPS FOR WRITING LIFE SCIENCES

The external examination for Life Sciences consists of two (2) question papers of 150 marks each. Each question paper covers a variety of content topics. Ask your teacher for an outline of the content topics and weighting of each topic in each question paper.

The duration of each question paper is 2½ hours and all questions are COMPULSORY.

Each Life Sciences question paper consists of THREE sections i.e. SECTION A (50 marks), SECTION B (two questions of 40 marks) and SECTION C (20 marks).

When answering a multiple choice question in Section A read the question and four options carefully, evaluate each option and eliminate each incorrect option.

In questions that require only a LETTER you only need to write down a LETTER e.g. ‘Give only the LETTER of the molecule that carries the amino acid’. Other questions might require you to write down both the LETTER and a NAME, for example of a part from a diagram.

Use the correct spelling when you use biological terminology in your answers. Use scientific names in terminology and avoid using common names e.g. .

You need to do all your drawings and graphs in pencil and labels should be in blue or black ink. You may not use graph paper when drawing graphs.

Make sure that you have all the necessary stationery for your examination e.g. blue or black pens, a pencil, an eraser, a ruler, a non-programmable calculator, protractor and a compass.

SCIENTIFIC INVESTIGATIONS:


3

What is a hypothesis? A hypothesis is an attempt to explain some event or observation using whatever information is currently available. It is a testable statement that may be accepted or rejected. A hypothesis must: (a) have two variables (dependent and independent variables); (b) state the relationship between the two variables; (c) be testable; and (d) state the independent variable first (cause) and then the dependent variable (effect).

Variables:

Controlled / fixed variable – refers to the factors that should be kept constant so that the results of an investigation can be considered valid.

Independent variable – refers to the factor that is being investigated. This factor is usually manipulated by the investigator either at the start of or during the course of the investigation. The independent variable appears on the X-axis of a graph.

Dependent variable – refers to the effect of the independent variable. This effect is usually measured in some way and appears on the Y-axis of a graph What is reliability?

The idea behind reliability is that any significant results of an investigation must be more than a once-off finding and be repeatable.

For the questions which required learners to state how the reliability of the investigation could have been improved, the following answers apply: Repeat the investigation OR Increase the sample size.

What is validity?

Validity questions show how the experiment/investigation was carried out. It is important to be sure that all the factors/variables have been controlled/ fixed except the variable/factor being tested.

In questions which require learners to suggest some factors that might have decreased the validity of an investigation, the answers should centre on the criticism of the scientific process; for example, some factors/variables that were not fixed/controlled when carrying out the investigation.

Question:

NOTE: Independent and dependent variables should be identified from the AIM of the investigation.

b

Life Science

1. Sciethe rwith moth

Ag

1.1 1.2 1.3 1.4 1.5 Answer

1.1 Consget pGet pDeciMakeDeciDeci

1.2 Age 1.3 Num1.4 Cond

Use 1.5 The

Type the follbelow for mo

PROTEIN S

es Telematic

ntists condurisk of her haDown syndr

her. Their fin

ge of mothe

State FOState theState theState ONState a c

rs:

sult with varpermission frpermission fde how large sure the sade on how tde on the tim

of the mothember of babie

duct the survmore than 5older the mo

lowing link hore practice

SYNTHESIS

cs resource G

ucted a surveaving a babyrome (per 5 ndings are su

er (years)

25 35 45

OUR planninge independene dependent NE way of imconclusion th

ious hospitarom hospitalfrom the mote the sampleample includhey will recome period th

er es born with vey over mo5 000 birthsother, the hig

http://wcedepoquestions on

Grade 12

ey to establisy with Down 000 births) oummarised i

g steps that nt variable variable

mproving the hat can be m

als / maternitls / maternitythers to use e should be des expectaord the datahey will use t

Down syndrore than one / increase gher the risk

ortal.co.za/eren scientific i

sh the relatiosyndrome. T

over a one-yn the table b

NumbeDown births)

need to be c

reliability ofmade of the r

ty homes to y homes the data / sample siznt mothers o to gather dat

rome year / repthe sample

k of having a

esource/7536investigation

onship betwThey recordyear period abelow.

er of babiessyndrome )

1015

30

considered f

f the results.results of this

gather and u

ze of various ag

ta

peat the survsize

a baby with D

61 in your brns:

ween the ageded the numband recorde

s born with (per 5 000

0 5

00

for this surve

s survey.

use the data

ges

vey

Down syndro

rowser OR sc

201

e of the mothber of babied the age of

ey.

a they can pr

ome

can the QR c

19

4

her and s born f the

(4) (1) (1) (1) (2)

rovide/

code


5

Protein synthesis is the process whereby proteins are made in living cells of an organism to form enzymes, hormones and new structures for cells. Amino acids are the basic building blocks of proteins. The nucleic acids DNA and RNA are involved in protein synthesis. The main steps of protein synthesis are transcription and translation.

Question:

Cell structure

(Grade 10)

The nucleus of the cell consists of the nuclear membrane,

nucleoplasm, nucleolus and

chromatin network (which forms

chromosomes)

DNA is found in the nucleus of the cell and

forms part of chromosomes

Ribosomes are mainly found in the

cytoplasm of the cell and are sites of

protein synthesis

RNA is found in the niucleus and

cytoplasm of a cell and plays a role in protein synthesis


6

Name and describe the process occurring in the nucleus which results in the formation of an mRNA molecule. Alternative question: Describe the process of transcription. Answer: The process is transcription The double helix DNA molecule unwinds When the hydrogen bonds breakthe DNA molecule unzips/2 DNA strands separate One strand is used as the template to form mRNA using free RNA nucleotidesfrom the nucleoplasm The mRNA is complementary to DNA/A-U, C-G This process is controlled by enzymes Question: Describe the process of translation. Answer: Each tRNA carries a specific amino acid tRNA carries the amino acid to the ribosome When the anticodon on the tRNA matches the codon on the mRNA Amino acids become attached in the sequence determined by the mRNA by peptide bonds to form the required protein Question:

Name/Give: Write down the answer without

further discussion

Describe: State in words the main points of a process or

structure or phenomena

Note: When answering questions with diagrams:

Read the introductory statement/s of the diagram.

It will tell you what the diagram is about. Study the diagram and write the missing

labels on the diagram before looking at the questions based on it.

This will help you to focus on the topic. Now read through the questions and answer

each question

At

s T

2

4 A

2

4

Life Science

A species ofthe formatio

Scientists dsequence to

The results

AMDNA

AMDNA

1. Give2. Give3. Give4. Desc

Answers:

1. GGT2 AAA3, UCA4. One

FromThe The This

Copy the folcode below

CELL DIVIS

es Telematic

f bacteria con of a secon

determined to find the DN

are shown in

INO ACID SA BASE SE

INO ACID SA BASE SE

e the DNA tre the codon fe the anticodcribe how th

T A A

of the base m ACG to ACtriplet ACG triplet ACC cresult in a c

llowing link iand downloa

SION

cs resource G

ontains a typnd type of pr

the amino aNA base seq

n the tables

SEQUENCEEQUENCE

SEQUENCEEQUENCE

iplet for the tfor lysine.

don for serinhe mutation

triplets on thCC codes for thcodes for the

change in the

in your internad more prac

Grade 12

pe of protein,rotein called

acid sequenquences that

below.

PORTIO Lysi

TT

PORTIO Lysi

TT

third amino

e caused a ch

he DNA has

e amino acide amino acide sequence

net browserctice questio

, called proteprotein 2, in

nce of eacht coded for p

ON OF PROTne ST T

ON OF PROTne ST T

acid from th

hange in the

s changed

d cysteined tryptophan of amino a

http://wcedepons on protei

ein 1. A mutnstead of pro

h protein. Thportions of th

TEIN 1 erine TCA

TEIN 2 erine TCA

e left in the structure of

n acid

portal.co.za/ein synthesis

tation occurrotein 1.

hey then ushese proteins

Proline GGT

Proline GGT

sequence fo

f the protein.

resource/752s:

201

red which re

sed the ams.

CysteineACG

TryptophaACC

or protein 2.

.

296 OR scan

19

7

sulted in

ino acid

e

an

(1) (1) (1) (4)

the QR

Life Science

MITOSIS AN

MEIOSIS:

(Chromo

(Centrom

(Ch

(Chroch

es Telematic

ND MEIOSIS

osomes arra

mere divide

hromosome

omatin netwromosome

Revision

cs resource G

S

ange at poldaughter

s into two a

es arrange

work shorteconsists of

of MITOSI

There are

Grade 12

Telopha

les of cell, cr cells have

Anapha

and chromapoles)

Metapha

in a single

Propha

ens and becf two chrom

IS which w

four phase

ase

cytokinesis e been form

ase

atids sepera)

ase

row on the

ase

come visiblematids joine

was covere

es during m

Chromat

Centrome

Diagramstranded

occurs andmed)

ate and mo

equator of

e as chromd by a cent

ed in Grade

itosis

tid

ere

m of a doubld chromoso

d two ident

ove to oppo

f the cell)

mosomes. A tromere)

e 10.

le –ome

201

ical

site

A

19

8

d

A

Life Science

Meiosis is a haploid cellsdivision (Me

Questions:

1. Stud

1.1 Iden

1.2 Give

1.3 How(a) (b)

1.4 The

(a) (b)

Answers:

1.1 Telo

1.2 TherEach

es Telematic

type of cell s (gametes oeiosis I) and

dy the diagra

ntify the pha

e TWO visibl

w many chromare presewere pre

cells in the dName TWdifferent Explain tfrom one

phase II

re are 4 cellsh cell contain

cs resource G

division wheor sex cells)the second

am of a phas

se in the dia

le reasons fo

mosomes: ent in EACHsent in the o

diagram are WO processfrom one anthe significa another.

sns only a sin

Grade 12

ereby a diplo. It is a contimeiotic divis

se during me

agram above

or your answ

cell in the doriginal cell a

NOT identices during m

nother. nce to a spe

ngle set of un

oid cell (somnuous proce

sion (meiosis

eiosis below.

e.

wer to QUES

diagram at the start o

cal. eiosis that le

ecies of the c

n-replicated

matic cell) uness which iss II)

.

STION 1.1.

of meiosis

ead to the ce cells being d

/single stra

ndergoes divs divided into

ells being

different

anded chrom

201

visions to foro the first me

(1)

(2)

(1) (1)

(2)

(3)

mosomes

19

9

rm eiotic

2

2 22 A 2 2 2

Life Science

1.3 (a) (b)

1.4 (a)

(b)

2. The

2.1 Namtakes

2.2 Desc2.3 Expl

Answers:

2.1 Prop

2.2 HomChroand

2.3 CrosIt maor nethere

es Telematic

Two/2Four/4/

CrossingRandom

The gamleading toThis incre

diagram bel

me the phases place. cribe the prolain the impo

phase I

mologous chromatids overgenetic infor

ssing over inay lead to neew characteefore affectin

cs resource G

/2 pairs

overarrangemen

etes that foro variation ineases a spe

ow shows c

e of meiosis

ocess of croortance of c

romosomes rlap/touch rmation is ex

troduces geew characterristics whichng the chanc

Grade 12

ntof chrom

rm will be gen the offsprin

ecies chance

rossing over

during which

ossing over. rossing over

lie next to eat points caxchanged/

enetic variatioristics which

h are unfavouces of surviv

mosomes on

enetically diffng/increases of surviva

r during mei

h the proces

r.

ach otherlled chiasma/swapped

onin gam are favouraurableval of the org

the equator

fferenting the genel

osis.

ss represent

ata

metes able

ganism/ na

e pool

ted above

atural selecti

201

(1) (3) (2)

on.

Explain: Express youanswer in acause-effecstatement areason sequence.

19

10

ur

ct or and

A

S

Life Science

ABNORMA

Mista Durin

calle Durin If the

abno If a n

zygo This


SENSES (E

es Telematic

L MEIOSIS:

akes can occng Anaphase

ed non-disjunng Anaphaseere is non-disormal gametnormal gameote will have

leads to Do


EYE AND EA

cs resource G

:

cur during me I one or mnction e II sister chsjunction of te with an exete fuses wit3 copies of wn syndrom


AR):

Grade 12

meiosis more homolog

hromatids of chromosom

xtra copy of cth a gamete chromosom

me


gous pairs o

one or moreme pair 21 in

chromosomewith an extr

me 21 (47 chr

http://wcedepons on meios

of chromosom

e chromosomhumans it lee 21 ra copy of chromosomes

portal.co.za/esis:

mes may no

mes may noeads to the f

hromosome instead of 4

resource/753

201

ot separate. A

ot separate formation of

21 the resul46)

301 OR scan

19

11

Also

an

lting

the QR

A

Life Science

Question:

1. The

1.1 State(a) (b)

1.2 NoctExpl

(a) (b)

1.3 Descto br

Answers:

1.1 (a) (b)

1.2 (a) (b)

1.3 The

es Telematic

diagram bel

e ONE functA C

turnal animalain how par

B of noctday C of noctday

cribe how thright light.

A R FC C F

The pupito allow m

The retinenabling

radial musc

cs resource G

ow represen

tion of part:

als sleep durrt:

turnal anima

turnal anima

he iris contro

Refraction of ocus light ra

Converts lighorms image

l/part B can more light to

a/part C hasthem to see

les of the iris

Grade 12

nts the struc

ring the day

als will differ

als will differ

ols the amou

lightORays on the ret stimuli to ims

dilate moreo enter the ey

s more rodse in dim light

s relax

cture of the h

and are acti

from that fo

from that fo

unt of light en

R etina mpulses

ye

t

human eye.

ve at night.

und in anima und in anima

ntering the e

OR

als that are

als that are

eye when a

201

active during

active during

person is ex

19

12

(1) (1)

g the (2)

g the (2)

xposed (4)

2

2 A 2

Life Science

CircuThe and

Question:

2. The mete

2.1 Explfrom

Answer:

2.1 P/CilCiliaQ/SuTensConvInco

Question:

3. The

3.1 Nam

es Telematic

ular muscle pupil constrless light en

diagram belers away. Ob

lain the role object B to

liary musclery body movuspensory ligsion on the levexity of lensming light ra

diagram bel

me the part o

cs resource G

of the iris coicts ters the eye

ow represenbject A is pla

of structureobject A.

s contract ves closer togaments slaens decreass increases/

ays are refra

ow represen

of the brain th

Grade 12

ontract

e

nts a humanaced 3 mete

es P and Q to

o lens acken ses /lens becomcted more

nts a part of

hat receives

n eye when ters away and

o ensure a c

e more conv

the human e

impulses fro

the person isd Object B is

clear image

vex

ear.

om:

s looking at as placed 8 m

if the person

201

an object thameters away

n moves his

19

13

at is 6 y.

focus (6)


14

(a) Parts A and B (1) (b) Part C (1) 3.2 Name the receptor found in part C. (1) 3.3 Explain TWO ways in which part A in the diagram is structurally suited to maintain balance. (4) Answers: 3.1 (a) Cerebellum (b) Cerebrum 3.2 Organ of Corti 3.3 The semi-circular canals/part A contain fluid/endolymph which moves when the person moves There are cristae present which convert the stimulus to an impulse/are sensitive to the movement of the fluid The canals lie on three different planes to detect movement in any directionQuestion: 4. While walking in the bush a boy hears a sound which he thinks is the roar of a lion. He immediately runs to safety. Describe how he hears the sound. Answer: 4. The pinna traps/directs the sound wavesinto the ear canal/meatus This causes the tympanic membrane to vibrate The vibration is transmitted to the auditory ossicles The ossicles amplify the vibrationand transmit it to the oval window The oval window vibratescreating wavesin the fluid/endolymph of the cochlea which stimulates the Organ of Cortito convert the wave into an impulse The impulse travels along the auditory nerveto the cerebrumwhere sound is interpreted

J

W

Life Science

NATURAL S


Jean–Bapti

‘Lawmuscafter

‘Laworga

Lamarck’s

All g Giraf caus The was form

Why Lamar

Acqu Orga

es Telematic

SELECTION


iste de Lam

w’ of use ancle or organr several genw’ of the inh

nism’s life ti

approach u

iraffes had sffes frequensing their neccharacteristthen passeding offspring

rck’s theory

uired characanisms do no

cs resource G

N, PUNCTUT


marck used tw

d disuse – twill develop

nerations. heritance of me will be p

using the gi

short necks otly stretchedcks to becomics of long nd on to the ng with longer

y is not acce

cteristics canot evolve be

Grade 12

TATED EQU


wo ‘laws’ to

the more anped. Muscle

acquired cpassed on to

raffe as an

originally d/used their nme longer necks acquirnext generatr necks than

eptable?

nnot be passecause they w

UILIBRIUM

http://wcedepons on natura

explain evo

n organism uand organ t

haracterist the next ge

example:

necks to rea

ed in this waion

n the generat

sed from onewant to evol

AND SPEC

portal.co.za/eral selection a

olution

uses a muscthat were no

ics – the streneration.

ach for leave

ay

tion before

e generationlve/Lamarck

CIATION

resource/753and speciati

cle or an orgaot used would

ronger musc

es of tall tree

n to the next.k’s theory is

201

306 OR scan ion:

an the strond simply dis

cle acquired

es

. deterministic

19

15

the QR

ger the appear

in the

c

S Tt

A

s

W

Life Science

Charles Da

Ther some Whe the g and The In th

long

Punctuated

Evolthrou

This throu

durin

SPECIATIO

There was vthe mainlandit was estab

Question: Describe th

Answer: Speciation osea/a bodyin neck lengconditionspopulations When the twoffspringt

es Telematic

rwin’s theo

re is a great e giraffes ha

en there is a giraffes with those with logiraffes withis way eachnecks.

d Equilibrium

ution involveugh natural salternates w

ugh natural sng which new

ON THROUG

variation in nd was separ

blished that s

he role of var

occurred throy of water an

gth within eac and underwbecame diff

wo populatiothus indicati

cs resource G

ory of evolut

deal of geneave longer nchange in thshorter neck

onger necksh longer neck

the next ge

m explains t

es long perioselection (knwith (is puncselection w species m

GH GEOGRA

neck length irated onto twspeciation of

riation in the

ough geogrand there wasch populatio

went natural ferent genons were mixng the forma

Grade 12

tion by natu

etic variationecks than othe environmks will die will survive ks will pass neration of g

the speed at

ods of time wnown as equctuated by) s

may form in a

APHIC ISOL

n a populatiwo islands wf the tortoise

e speciation o

aphical isolas no gene flo

on. Each poselection indotypically anxed againthation of a ne

ural selectio

n in the girafthers

ment/competi

since they con the allelegiraffes have

t which evolu

where specieuilibrium). hort periods

a short period

LATION

on of Galapawith different es had occur

of the Galap

tion.The oow betweeopulation wadependently

nd phenotyphey were un

ew species

on using th

ffe populatio

ition for reso

could reach e for longer ne a higher pr

ution takes p

es do not ch

s of time whe

d of time.

agos tortoiseenvironmen

rred.

pagos tortois

riginal popuen the two poas exposed y. Over a loically.

nable to inter

e giraffe as

n

ources

the leaves onecks to theroportion of

place:

hange or cha

ere rapid cha

es. The origntal condition

ses.

lation was sopulations. Tto different eong period o

rbreed to pro

201

s an exampl

of tall trees eir offspring

individuals w

ange gradua

anges occur

ginal populatns. Many ye

separated byThere was venvironmentof time the tw

oduce fertile

19

16

le

with

ally

r

ion from ars later

(8)

y the variation tal wo

e


17

HOMEOSTASIS

Homeostasis is the process of maintaining a constant internal environment within the body. The internal environment refers to the blood and tissue fluid that surrounds the cells of the body. Homeostasis enables the body to function efficiently, despite changes that might occur in the external or internal environment. Changes in temperature, glucose levels, carbon dioxide levels, water levels and salt levels of the internal environment affects the homeostatic balance of the body. Negative feedback mechanisms operate in the human body to detect changes or imbalances in the internal environment and to restore the balance. Homeostatic control of blood sugar levels The pancreas, located just below the stomach, is composed of two types of cells:

Normal pancreatic cells that secrete digestive juice (pancreatic juice) which contains `enzymes for digestion.

The islets of Langerhans that secrete two hormones, namely insulin and glucagon. The pancreas is both an exocrine gland (secretes pancreatic juice into a pancreatic duct which opens in the duodenum) and endocrine gland (secretes the hormones namely, insulin and glucagon directly into the bloodstream).

Revise Homeostatic

control

(Grade 11)

Gaseous exchange:

Homeostatic control of breathing

Excretion:

Homeostatic control of water and

salts

Nutrition:

Hormonal control of

blood sugar levels

Hormones are organic chemical messengers secreted by endocrine glands into the bloodstream where it is transported to cells and organs on which it has a specific regulatory effect.

Exocrine glands release their secretions in ducts. Endocrine glands release their secretions directly into the bloodstream


18

Control of blood sugar levels (glucose concentration in blood)

When the glucose level in the blood increases above normal, the pancreas is stimulated The pancreas secretes insulin into the blood Insulin travels in the blood to the liver and stimulates the conversion of glucose to glycogen

which is then stored The glucose level in the blood decreases and returns to normal

When the glucose level in the blood decreases below normal levels, the pancreas is stimulated

The pancreas secretes glucagon into the blood Glucagon travels in the blood to the liver and stimulates the conversion of stored glycogen to

glucose The glucose level in the blood increases and returns to normal.

Homeostatic control of breathing

Receptor cells in the carotid artery and in the wall of the aorta are very sensitive to changes in the carbon dioxide concentration in the blood.

When the carbon dioxide level in the blood increases e.g. after or during exercise, the receptor cells in the carotid artery and wall of the aorta are stimulated

These receptors send nerve impulses to the medulla oblongata in the brain The medulla oblongata sends nerve impulses to the diaphragm and intercostal muscles

(breathing muscles) to contract more actively and increasing the rate and depth of breathing The medulla oblongata also sends nerve impulses to the heart muscle to increase the heart

rate More carbon dioxide is transported to the lungs and exhaled from the lungs The carbon dioxide level in the blood returns to normal.

Homeostatic control of water content of the blood (osmoregulation)

The hormone ADH (anti-diuretic hormone), secreted by the hypophysis (pituitary gland),

regulates the water content of the blood.

The hypophysis is an endocrine gland at the base of the brain that secretes a number of hormones in the blood.

Glucose – a carbohydrate and building block of some carbohydrates Glycogen – a carbohydrate and the storage form of glucose Glucagon –hormone that increases the blood glucose level


19

When the blood has less water than normal e.g. when a person is active and sweating a lot or taking in very little liquids

The hypothalamus is stimulated and sends impulses to the hypophysis to secrete more ADH ADH travels in the blood to the kidneys and makes the walls of the distal convoluted tubules

and collecting ducts more permeable to water More water is re-absorbed from the tubules and is passed to the surrounding blood vessels Urine becomes more concentrated and its volume decreases The water level in the blood increases and returns to normal

When the blood has more water than normal e.g. when a person is inactive and sweating less or taking in a lot of liquids

The hypothalamus is stimulated and sends impulses to the hypophysis to secrete less ADH Less ADH travels in the blood to the kidneys and the walls of the distal convoluted tubules and

collecting ducts become less permeable to water Less water is re-absorbed from the tubules and is passed to the surrounding blood vessels Urine becomes less concentrated (dilute) and its volume increases Large amount of water is excreted in the urine The water level in the blood decreases and returns to normal Homeostatic control of salt balance of the blood

The hormone aldosterone, which is secreted by the adrenal gland regulates the

concentration of salts e.g. sodium ions in the blood.

When the salt concentration in the blood becomes too low

The adrenal gland is stimulated to secrete more aldosterone Aldosterone increases the re-absorption of sodium ions from the distal convoluted tubules and

collecting duct into the surrounding blood vessels The concentration of sodium ions in the blood vessels increases and returns to normal.

When the salt concentration in the blood becomes too high

The adrenal gland is stimulated to secrete less aldosterone The re-absorption of sodium ions from the distal convoluted tubules and collecting duct into the

surrounding blood vessels decreases The concentration of sodium ions in the blood vessels decreases and returns to normal.

Adrenal glands are endocrine glands located at the top of each kidney

T

A

A

T

T

Life Science

The procesRole of swecontrolling te

Question: A man was released aftDescribe ho

Answer: Body tempeThe hypothaBlood vesseLess blood fLess heat isLess blood iSweat glandThere is less


es Telematic

ss of tempereating, vasoemperature/

accidentallyer six hours

ow his body m

erature is regalamus sendels constrictflows to the

s lost fromis sent to theds become les evaporatio


cs resource G

rature reguodilation and/thermoregu

locked in a when a co-w

maintained h

gulated by thds impulses (become nskin the skin e sweat glaness active/

on of sweat


Grade 12

lation: d vasoconslation:

cool room inworker hearhis temperat

he hypothalato the blood

narrow)/vaso

nds /Less sweat and less co


END

striction in n

n which the td his cries foture at 37 oC

amus of the vessels o

oconstriction

is releasedooling of the

http://wcedepons on home

D OF DOCU

negative feed

temperatureor help.

C.

e brain of the skin n occurs

skin

portal.co.za/eeostasis:

UMENT

dback mech

e was 8 oC. H

resource/752

201

hanism for

He was only

291 OR scan

19

20

y

(8)

the QR

TELEMATICS 2019 LIFE SCIENCES Grade 12 · Life Sciences Telematics resource Grade 12 2019 2 ... For...

Documents

Transcript of TELEMATICS 2019 LIFE SCIENCES Grade 12 · Life Sciences Telematics resource Grade 12 2019 2 ... For...