Life Sciences Grade 12 P1 Eastern Cape Mock 2013 Memo (Eng)

Downloaded from hlayiso.com Province of the EASTERN CAPE EDUCATION NATIONAL SENIOR CERTIFICATE GRADE 12 SEPTEMBER 2013 LIFE SCIENCES P1 MEMORANDUM MARKS: 150 This memorandum consists of 10 pages.

Downloaded from hlayiso.com 2 LIFE SCIENCES P1 (SEPTEMBER 2013) SECTION A QUESTION 1 1.1 1.1.1 A  1.1.2 C  1.1.3 B  1.1.4 B  1.1.5 B  1.1.6 C  1.1.7 A  1.1.8 B  1.1.9 D  1.1.10 B  (10 x 2) (20) 1.2 1.2.1 Allopatric (Geographical) speciation  1.2.2 Natural selection  1.2.3 Gonosomes / Sex chromosomes  1.2.4 Phenotype  1.2.5 Cloning 1.2.6 Chiasma  1.2.7 Polygenic inheritance  (7 x 1) (7) 1.3 1.3.1 A only  1.3.2 B only  1.3.3 A only  1.3.4 None  1.3.5 A only  1.3.6 B only  1.3.7 A only  (7 x 2) (14) 1.4 1.4.1 Chromosomal non-disjunction/chromosomal non-separation  (1) 1.4.2 Plants  (1) 1.4.3 Polyploidy  (1) 1.4.4 (a) 8 (diploid/2n)  (1) (1) (b) 8 (diploid/2n)  (c) 16 (tetraploid/4n)  (1) 1.4.5 8 (1) 1.4.6 Production of:  Larger plants   Larger flowers   Larger fruits  (Mark first two only) (Any 2) (2) TOTAL SECTION A: 50

Downloaded from hlayiso.com (SEPTEMBER 2013) LIFE SCIENCES P1 3 SECTION B QUESTION 2 2.1 2.1.1 Protein synthesis  (1) 2.1.2 (a) The nucleus  (1) (b) The ribosome  (1) (c) Transcription  (1) (d) Translation  (1) 2.1.3 (a) Proteins  (1) (b) Amino acids  (1) (c) Peptide bond  (1) 2.1.4 (a) CAU (3) (b) CCG (3) 2.1.5 3 (1) 2.1.6 P – Valine  Q – Histidine  R – Glycine  (3) 2.2 2.2.1 “Three-parent” fertility treatment.  / “Three parent in vitro fertilisation”  (1) 2.2.2 Mitochondrial defect/Faulty mitochondrial DNA  (1) 2.2.3 One in 6 500 children  (1) 2.2.4  The technique involves the replacement of defective mitochondria from the embryo.   A new mitochondrion is inserted from a female donor  so that the baby does not inherit defects from its mother.  This technique is carried out in the laboratory (in vitro process).  (3) 2.2.5  Fatal heart problems   Liver failure   Brain disorders   Blindness   Muscular weakness  (Any 3 x 1) (3) 2.2.6  The traditional concept of parenthood and family are challenged.   Playing God.   Future dilemma of the child explaining the concept of his/her parents.   Unnatural process (against the nature)  (Any other relevant answers) (3) [30]

Downloaded from hlayiso.com 4 LIFE SCIENCES P1 (SEPTEMBER 2013) QUESTION 3 3.1 3.1.1 A – Australopithecus  (1) B – Homo habilis  (1) C – Homo erectus  (1) D – Homo neanderthalensis  (1) E – Homo sapiens  (1) 3.1.2  Freely rotating (movable) long upper limbs   Elbow joints allowing rotation of the forearm.   Flat nails instead of claws / bare, sensitive finger tips.   Flexible wrists that are capable of rotating at least 180ͦ..  Eyes in front   Olfactory brain centres reduced /reduced sense of smell   Opposable thumbs for power grip and precision grip   Larger brain   Binocular vision /stereoscopic vision  Sexual dimorphism   Two teats   Five fingers   Production of fewer off-spring   Upright posture /bipedal (Any 5 x 1) (5) 3.1.3 Hominidae  (1) 3.1.4  Bipedalism   A flat face   Gently curved jaw line  . . .  Dental formula  . . .  Larger brain (average brain size of 1 400 mℓ)   Use of artificial language to communicate   More pronounced chin  (Any 3 x 1) (3)

Downloaded from hlayiso.com (SEPTEMBER 2013) LIFE SCIENCES P1 5 3.2 3.2.1 The scientific view  Is based on scientific observations, deductions and experiments.   Information is collected, analysed and conclusions are drawn.   Life evolved from the most basic organism.   Organisms have and are constantly changing.   Organisms evolved and adjusted to certain environments.   Theories are developed from scientific enquiries.   Scientists believe that organisms change to make them better adapted to their environment.   All scientists believe that organisms develop due to natural selection.   They believe that new groups are formed by evolution.  (Any 2 x 1) (2) Creationist view  All living forms have been created by a supreme being.   Organisms that have been created have not changed since their creation.   Different forms of life were designed to function in particular settings.   In some cases the theories are in the form of stories.   Some accept organisms can change, but these changes take place to make them better adapted to their environment.   Some accept that new species can be formed by natural selection due to variation.   They do not believe that new groups can be formed by evolution.   They accept the absolute truth as written in sacred texts of the religion to which they adhere.   They accept moral, ethical and philosophical interpretations.   Some have taken the view that evolution can be disproved by the idea of irreducible complexity.  (Any 2 x 1) (2)

Downloaded from hlayiso.com 6 LIFE SCIENCES P1 (SEPTEMBER 2013) 3.2.2  Repeat the experiment several times.   Do test under the same conditions.   Experiment is done with a larger sample. (Mark first two only)    (Any 2 x 1) (2) 3.2.3 To inform people of their findings so that they can critique  / verify their findings  / use it for future research / acknowledge ownership of the findings.  (Any 2 x 1) (2) 3.2.4  Paleontology   Comparative anatomy   Biogeography   Molecular biology and genetics   Comparative embryology  (Any 3 1) (3) 3.3 3.3.1 Spraying DDT over a period of 32 weeks  will eradicate the mosquito population.  (2) 3.3.2 There was a substantial increase in the population of mosquito over 32 weeks.  OR DDT had no effect on the size of mosquito population.  (1) 3.3.3 Mosquitoes developed resistance against DDT  over a period of 32 weeks.  (2) [30] TOTAL SECTION B: 60

Downloaded from hlayiso.com (SEPTEMBER 2013) LIFE SCIENCES P1 7 SECTION C QUESTION 4 4.1 4.1.1 USA (United States of America)  (1) 4.1.2 Increasing trend  (1) 4.1.3 25 – 21 = 4   100  16% (3) 4.1.4  Emergence of super weeds   Environmental pollution  (Any 1 x 1) (1) 4.1.5 67 360 194,5 124 25 360 72,6 124 2 marks 360 = 67,8 9 360 26,1 124

Downloaded from hlayiso.com 8 LIFE SCIENCES P1 (SEPTEMBER 2013) Mark allocation of the graph Calculations/Working to determine 2 Marks: All four calculations the correct proportions correct 1 Mark: 1 to 3 calculations correct Correct type of graph (pie chart) 1 Title of graph 1 Proportions accurate for each 4 Marks: All four sectors correct. sectors/slice labelled key (Use transparency template) (1 x mark / sector) (8) 4.2 4.2.1 (Any 6 x 1) (6) 4.3 “Out of Africa hypothesis” Scientists believe that Homo sapiens probably evolved in Southern Africa and spread throughout the rest of the world.  This means that all the people on planet earth evolved from an ancestral population that originated only 200 000 years ago.  About 1,9 million years ago, long before Homo sapiens appeared, some Homo erectus  moved out of Africa using the land bridge which developed when the sea-level dropped during the ice ages.  They probably moved beyond Africa and then spread across the grasslands of Asia and Europe.  About 100 000 years ago, Homo sapiens also moved out of Africa  but this population could not survive.  A second migration of Homo sapiens  happened about 70 000 years ago.  This group and their descendants moved into Middle-East and spread over the rest of the world, replacing the other Homo sapiens that had migrated earlier.  About 50 000 years ago they reached South Asia  and about 40 000 years ago they reached Australia.  They probably reached America via Asia only 20 000 years ago.  (Any 3 x 1) (3)

Downloaded from hlayiso.com (SEPTEMBER 2013) LIFE SCIENCES P1 9 Genetic evidence in support “Out of Africa hypothesis”  DNA is used for the purpose of tracing ancestry.   A search is made for mutations since individuals who have the same mutation must share the same common ancestor.  (markers of descent). (a) DNA from the Y-chromosomes Since the major part of Y-chromosomes of males does not undergo crossing over with its mismatched X chromosomes,  DNA on the Y- chromosomes is passed on from father to son without being mixed with nucleotides from the mother.  Therefore, mutant nucleotides can be traced from son to father to grandfather to great grandfather and so on.  This way, our male ancestry can be traced.  By using mutant nucleotides on Y-chromosomal DNA as markers of descent, scientists have traced the lineage of every man alive to a common ancestor who lived in East Africa about 60 000 years ago.  (Any 4 x 1) (4) (b) Mitochondrial DNA DNA found in the mitochondria is known as mitochondrial DNA. Since the mitochondrial DNA  of the sperm cell does not fuse with that of the egg cell,  it is passed on from mother to child.  By following mutant nucleotides in mitochondrial DNA,  scientists are able to trace the female line of descent.  Analysis of mitochondrial DNA leads to an ancestral female who lived in East Africa, around 150 000 years ago.  Scientists believe other species of humans were also present at this time. However, those other species all became extinct and our species (Homo sapiens) was the only one that survived.  (Any 4 x 1) (4) On the basis of DNA analysis, scientists believe that from East Africa early humans migrated across the continent of Africa. Then they moved out of the continent through north-east Africa. (c) Fossil evidence to support “Out of Africa” theory The world’s oldest  and richest concentration of fossils of early humans  has been found in Africa. Some of examples of excavated fossils of early humans found in Africa are listed below: (2)  6 to 7 million years old bipedal primates, Sahelanthropus tchadensis  found in Chad.   Little Foot  is a 3,9 to 4,2 million years old fossil discovered in the Sterkfontein Caves.   Lucy  is a 3,2 million years old fossil discovered in Ethiopia. 

Downloaded from hlayiso.com 10 LIFE SCIENCES P1 (SEPTEMBER 2013)  Taung Child (Australopithecus Africans) , a 2,6 to 2,8 million old fossil found in the Northern Cape.   Mr. Ples (Australopithecus africanus)  2,6 million years old fossil found in the Sterkfontein Caves.   Kromdraai (Paranthropus robustus)  was also discovered in Sterkfontein.   1,2 to 2,2 million years old fossil Paranthropus boisei  was discovered in Tanzania.   Fossil of Homo habilis was discovered in Tanzania.   Florisbad man (an earlier Homo sapiens),  a 250 000 year fossil was discovered in the Free State.  (Any 2 examples) (4) No flow chart will be credited as an essay. Marks Descriptions 3 Well structured – demonstrates insight and understanding of question 2 Minor gaps in the answer. 1 Attempted but with significant gaps in the answer 0 Not attempted/nothing written other than question number Synthesis (3) TOTAL SECTION C: 40 GRAND TOTAL: 150