Life Sciences Grade 12 KZN March 2022 Paper & Memo

KWAZULU-NATAl PROVINCE EDUCATION REPUBLIC OF SOUTH AFRICA NATIONAL SENIOR CERTIFICATE II II II II II MARKS: 60 This question paper consists of 10 pages.

- INSTRUCTIONS AND INFORMATION Read the following instructions carefully before answering the questions. 1. Answer ALL the questions. 2. Write ALL the answers in the ANSWER BOOK. 3. Start the answers to each question at the top of a NEW page. 4. Number the answers correctly according to the numbering system used in this question paper. 5. Present your answers according to the instructions of each questiot,O,S­ 6. Do ALL drawings in pencil and label them in blue or black ink,. V 7. Draw diagrams, tables or flow charts only when asked to do�� 8. The diagrams in this question paper are NOT necessafJawn to scale. 9. Do NOT use graph paper. 10. You may use a non-programmable calcu��otractor and a compass. 11. Write neatly and legibly. Copyright reserved Please Turn Over

Life March Common TeSl 2022 SECTION A QUESTION 1 1.1 Various options are provided as possible answers to the following questions. Choose the answer and write only the letter (A to D) next to the question number (1.1.1 to 1.1.3) in the ANSWER BOOK, for example 1.1.4 D. 1.1.1 Which part. of sperm cell has a nucleus that fuses with a nucleus of an egg cell dur ng fertilisation? r � Acrosom B Head C Neck Tail 1.1.2 The diagram below represents the male reproductive system. ---B Which part indicates the tube that transports semen and the gland that secretes testosterone respectively? A A and B B Dand E C A and C D A and E Copyright reserved Please Turn Over

Downloaded from Stanmor'mgysics.com 1.1.3 Study the following factors related to Down syndrome as an example of abnormal meiosis. (i) Non-disjunction during anaphase in pair number 23 (ii) Non-disjunction of chromosomes at position 21 during Anaphase (iii) 47 chromosomes in somatic cells as a result of non-disjunction at any position of chromosome during anaphase (iv) The fusion between an abnormal gamete (extra copy of chromosome in pair 21) and a normal gamete Which ONE of the following combinations are related to Down syndrome as an example of abnormal meiosis? A (i), (ii) and (iv) only B (ii), ((iii) and (iv) only C (ii) and (iv) only D (iii) and (iv) only (3 X 2) (6) 1.2 Give the correct biological term for each of the following descriptions. Write only the term next to the question number (1.2.1 to 1.2.4) in the ANSWER BOOK. 1.2.1 The natural shape of a DNA molecule 1.2.2 The type of bond found between nitrogenous bases 1.2.3 The point at which chromatids overlap during crossing over 1.2.4 The type of egg produced by bird that has extra-embryonic membranes (4 X 1 ) (4) 1.3 Indicate whether each of the descriptions in COLUMN I applies to A ONLY, B ONLY, BOTH A AND B or NONE of the items in COLUMN 11. Write A only, B only, both A and B, or none next to the question number (1.3.1 to 1.3.3) in the ANSWER BOOK. COLUMN I COLUMN II 1.3.1 A nitrogenous base found in A: Adenine mRNA only B: Uracil 1.3.2 The phase of meiosis during which A: Metaphase I random arrangement of B: Metaphase 11 chromosomes occur 1.3.3 The hormone that maintains the A: LH thickness of the endometrium B: FSH (3 X 2) (6) Copyright reserved Please Turn Over

ute March Common Test 2022 1.4 The diagram below represents two forms of chromosomes. Chromosome I Chromosome II 1.4.1 Give the LETTER and the NAME of the part that joins two chromatids together. (2) 1.4.2 Name the: (a) Phase that resulted in the formation of chromosome II. (1) (b) Process that resulted in the formation of chromosome II. (1) (4) TOTAL SECTION A: 20 Copyright reserved Please Turn Over

SECTION B QUESTION 2 2.1 The diagram below shows a process of protein synthesis, □ ;---A (il't-------- B .ti i{ll 2.1.1 Identify: (a) Organelle B (1 ) (b ) Monomer C (1) 2.1.2 State the process of protein synthesis during which molecule A is formed. (1) 2.1.3 Explain the significance of molecule A during protein synthesis? (2) 2.1.4 A short piece of DNA that is 12 nitrogenous bases long, was analysed to determine the number of nitrogenous bases in molecule A in the diagram. The results are shown in the table below Bases I Cytosine I Guanine I Adenine Thymine DNA strand I 4 I 3 I - 2 Calculate the percentage of uracil in molecule A in the diagram and using the table above. Show au working. (3) 2.1.5 Describe the process of translation. (5) (13) Copyright reserved Please Turn Over

March Common Test 2022 2.2 The diagrams below represent the phase of meiosis. � I \ I \ I \ I I \ \ / \ --d:>�-A ...,a)::> \ I \ �---..,_____ B \ \ 2.2.1 Identify part: (a) A (1) (b) C (1) 2.2.2 Name the: (a) Phase of meiosis shown in the diagram above. (1) (b) Process that resulted in the appearance of part A in the diagram. (1) 2.2.3 Name and describe the phase of meiosis that occurs before the one named in QUESTION 2.2.2. (3) (7) [20] Copyright reserved Please Turn Over

__ ,, vu,,", ,v,, , "'"' .!.VL.L. NSC QUESTION 3 3.1 The diagram below shows the type of fertilisation in frogs. 3.1.1 State the type of fertilisation shown in frogs above. (1) 3.1.2 Are the frogs viviparous, ovoviviparous, or oviparous? (1) 3.1.3 Give a reason for your answer in QUESTION 3.1.2. (2 ) 3.1.4 State ONE significance for this type of fertilisation in frogs to occur in water. (1) (5) Copyright reserved Please Turn Over

3.2 Men never stop producing sperms unless some specific diseases like diabetes, high blood pressure and other diseases. Sperm count changes as a man ages. Other several indirect factors might have an effect on older men fertility. Scientists wanted to investigate whether the age had an impact on men fertility in 2002. The average number of births per 1000 men was calculated and used as an indication of fertility. The data was collected from home affairs as per birth certificates issued in 2002. The table below shows the results of their investigation. AGE BIRTH RATE PER 1000 MEN IN 2002 15-19 18 20-24 78 25-29 105 30-34 100 35-39 50 40-44 21 45-49 5 50-55 1 55 and older 0 3.2.1 Identify the: (a) Dependent variable (1) (b) Independent variable (1) 3.2.2 State how the dependent variable in QUESTION 3.2.1 (a) was determined. (1) 3.2.3 Name TWO planning steps that were taken before the beginning of this investigation. (2) 3.2.4 Give the conclusion of the above investigation based on the results shown on the table above. (2) (7) Copyright reserved Please Turn Over

3.3 The diagram below shows the changes in the concentraton of hormones in the blood and uterine membrane during a menstrual cycle. A B C Endometrium 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 161718 19 20 21 22 23 24 25 26 27 28 3.3.1 Identify hormone: (a) A ( 1) (b) 0 (1) 3.3.2 Describe the relationship between the level of hormone C and the endometrium from day 9 to day 13. (2) 3.3.3 Explain why the level of hormone B increases after day 23 during menstrual cycle. (4) (8) TOTAL SECTION B: 40 GRAND TOTAL: 60 Copyright reserved

Department Education PROVINCE OF KWAZULU-NATAL DIRECTORATE:· Private Bag X01 EAST END, 4018 Provincial Examination Administration Malgate Bu1id1ng, 72 Stalwart S1melane Street. Durban. 4000 Tel· 0313321896 C KHUMALO ' ' ' ' TO: THE CHIEF INVIGILATOR OF ALL SCHOOLS OFFERING: · LIFE SCIENCES NATIONAL SENIOR CERTIFICATE: MARCH 2022 COMMON TEST: GRADE 12 ERRATA Page 10 Please take note of the following information that was omitted for the diagram in 3.3 A and B are pituitary hormones and C and D are ovarian hormones t candidates are informed of the E·rrata. MS N.E. MKHIZE I] n DI RECTOR: EXAMINATION AND ASSESSMENT GROWING KWAZULU-NATAL TOGETHER

rff'RfAt;com KWAZULU-NATAL PROVINCE EDUCATION REPUBLIC OF SOUTH AFRICA NATIONAL SENIOR CERTIFICATE ( GRADE 12 ) � �---------------------------------------------��� 11 LIFE SCIENCES II II II MARCH 2022 COMMON TEST II II II II MARKING GUIDELINE II II II II II � � ������������������������������������������������ MARKS: 60 This memorandum consists of 6 pages DULY SIGNED BY: V.S.T. NYUSWA A. SINGH F. MEMELA

Life DewBloMarch Marking guideline 2022 2 PRINCIPLES RELATED TO MARKING LIFE SCIENCES 1. If more information than marks allocated is given Stop marking when maximum marks is reached and put a wavy line and 'max· in the right-hand margin. 2. If, for example, three reasons are required and five are given Mark the first three irrespective of whether all or some are correct/incorrect. 3. If whole process is given when only a part of it is required Read all and credit the relevant part. 4. If comparisons are asked for, but descriptions are given Accept if the differences/similarities are clear. 5. If tabulation is required, but paragraphs are given Candidates will lose marks for not tabulating. 6. If diagrams are given with annotations when descriptions are required Candidates will lose marks. 7. If flow charts are given instead of descriptions Candidates will lose marks. 8. If sequence is muddled and links do not make sense Where sequence and links are correct, credit. Where sequence and links are incorrect, do not credit. If sequence and links become correct again, resume credit. 9. Non-recognised abbreviations Accept if first defined in answer. If not defined, do not credit the unrecognised abbreviation, but credit the rest of the answer if correct. 10. Wrong numbering If answer fits into the correct sequence of questions, but the wrong number is given, it is acceptable. 11. If language used changes the intended meaning Do not accept. 12. Spelling errors If recognisable, accept the answer, provided it does not mean something else in Life Sciences or if it is out of context. 13. If common names are given in terminology Accept, provided it was accepted at the national memo discussion meeting. 14. If only the letter is asked for, but only the name is given (and vice versa) Do not credit. Copyright reserved Please turn over

15. If units are not given in measurements Candidates will lose marks. Memorandum will allocate marks for units separately. 16. Be sensitive to the sense of an answer, which may be stated in a different way. 17. Caption All illustrations (diagrams, graphs, tables, etc.) must have a caption. Copyright reserved Please turn over

March Marking guideline 2022 4 SECTION A QUESTION 1 1.1 1.1.1 B✓✓ 1.1.2 D✓✓ 1.1.3 C✓✓ (3 X 2) (6) 1.2 1.2.1 Double helix✓ 1.2.2 Hydrogen✓bond 1.2.3 Chiasmata✓ 1.2.4 Amniotic✓ egg (4 X 1) (4) 1.3 1.3.1 None✓✓ 1.3.2 Both A and B✓✓ 1.3.3 None✓✓ (3 X 2) (6) 1.4 1.4.1 C✓ Centromere✓ (2) 1.4.2 (a) lnterphase✓ (1) (b) DNA replication✓ (1) (4) TOTAL SECTION A: 20 SECTION B QUESTION 2 2.1 2.1.1 (a) Ribosome✓ (1) (a) Amino acid✓ (1) 2.1.2 Transcription✓ (1) 2.1.3 - Copy the coded message from the DNA molecule✓ - and carry it to the ribosomes✓ - for the synthesis of a required protein✓ (2) 2.1.4 3 ✓ X 100✓ = 25✓ 12 (3) Copyright reserved Please turn over

March Marking guideline 2022 2.1.5 - Each tRNA carries a specific amino acid✓ - When the anticodon on the tRNA✓ - matches the codon on the mRNA✓ - then tRNA brings the required amino acid to the ribosome✓ - Amino acids become attached to each other by peptide bonds✓ (5 ) - to form the required protein✓ Any (13) 2.2 2.2.1 (a) Chromatid✓ (1) (b) Cell membrane✓ (1) 2.2.2 (a) Anaphase 11 ✓ (1) (b) Crossing over✓ (1) 2.2.3 - Metaphase II*✓ - Random arrangement of chromosomes along the equator✓ - singly✓ - Chromosomes attach to the spindle fibres with centromere✓ (*compulsory 1 + Any 2) (3) (7) [20] QUESTION 3 3.1 3.1.1 External✓fertilisation (1) 3.1.2 Oviparous✓ (1) 3. 1.3 -Lays eggs✓ -young develop in the egg outside the mother's body✓ (2) 3.1.4 - Prevents drying out of gametes✓ - Allow sperm cells to swim towards eggs cells✓ Any (1) Mark the first ONE only (5) 3.2 3.2.1 (a) Men fertility✓ (1) (b) Age✓ (1) 3.2.2 No answer Copyright reserved Please turn over

March Marking guideline 2022 3.2.3 - Ask the permission from participants✓ -Decide on recording tool✓ -Decide on place for the investigation✓ -Decide on time for the investigation✓ (2) -Decide on sample size✓ Any Mark the first TWO only (4) 3.2.4 No answer 3.3 3.3.1 (a) LH✓ (1) (b) Progesterone✓ (1) 3.3.2 As hormone Cfoestrogen increases, the endometrium thickness (2) increases✓✓ 3.3.3 - Since no fertilisation has taken place✓ - Progesterone level in the blood decreases✓ - as corpus luteum degenerates✓ - and no inhibition of pituitary gland✓ - from producing FSH✓/hormone B Any (4) (8) [17] TOTAL SECTION B: 37 GRAND TOTAL: (57) Use the table below to adjust marks to 60 Marks obtained 0-9 Add 0 10- 29 Add 1 30- 48 Add 2 49-57 Add 3 Copyright reserved