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8/8/2019 Mark scheme P2 Melaka (SPM)

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TRIAL SPM MELAKA 2010MARKING SCHEMEBIOLOGY PAPER 2

Section A

No Marking CriteriaMark

Max

1(a)(i)(ii)

(b)(i)

(b)(ii)

(c)

(d)

LeafP:: Pollisade mesophyllQ: Sponge mesophyllR: XylemS: Floem

Absorbing sun light (/)

y consist abundant of chloroplast that contain chlorophyll

y chlorophyll absorb sunlight for photosynthesis

R: consist of xylem vessel, tracheid, parenchyma and xylemfibre; more than one type of cell

S: consist of cell companion cell, sieve tube, parenchyma,phloem fibre; more than one type of cell.

- spinach cell become flaccid // plasmolysed- water diffuse out of the cell by osmosis- the cytoplasma abd the vacuole will shrink- the cell membrane pull away from the cell wall

13 = 1 mark4= 2 marks

1

11

11

1111

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2

1

2

2

4

12marks

2(a)(i)

(ii)

(b)

(c) (i)(ii)

(d)

(e)

P: chromosomeR: centromer

Hold two sister chromatid together

Diagram 2.2: Chromosomes align at the equator of the spindlefibre / metaphase plate

Diagram 2.3: Homologous chromosomes align at the equater ofthe spindle fibre / metaphase plate.

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1. ovum / egg cell2. sperm / spermatids

- Mitosis produce new cells- That are identical to planaria body cell- The cells are used to regenerate new part / organ of planaria

bodies

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2

1

2

2

2

312

mark


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3.(a)

(b)(i)

(ii)

(c) (i)

(ii)

d(i)

(ii)

Trachea /Rib cage / ribs

To increase / decrease the pressure / volume in the bell jar

- elastic

- can expand (inhalation) and contract/ decrease in size(exhalation )

- both balloons decreasein size

- the string represent the diaphragm- when the diaphragm muscles contract,- the volume of the thorax increase

- this will decrease the thorax pressure- air will be inhale

- To prevent oxygen gas being absorbed by the potassiumpyrogallol solution as it can absorb both carbon dioxideand oxygen .

- The concentration of carbon dioxide is higher in the cellbody; released from the cellular respiration

- Carbon dioxide diffuse into the blood to be transport tothe lungs.

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2

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12marks

4(a)(i)

(ii)

(b)(i)

Menstruation

The endometrium begins to break down1

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(ii)

(c )(i)

(ii)

(d)

(e)

P1 : The endometrium begin to became thicker, for preparationfor the implantation of a fertilized ovum

P2 : The endometrium keep thickening due to the level ofprogesterone and oestrogen continue to rise becausefertilization occurs.

P3 : The corpus luteum continues to secrete oestrogen andprogesterone

P1 : Increasing in progesterone level will stimulate the uterinewall to became thicker

P2 : When the fertilization occur, the level of progesteronecontinue to rise to ensure the uterine walls continue to growand nourish the embryo

P1 :The level of progesterone become lowerP2: Ovaries are less stimulated by FSH and LH

P3: P2 lead to inhibits the development of the follicles andovulation

F : Cell V is similar to cell W but is different from cell X.P : Cell V and cell W are products of mitosis whereas cell

X is a product of meiosis.

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5( a)

(b)(i)

(ii)

( c )

(i)

(ii)(iii)

(d)

Process R.: Meiosis

Gamete T: 22 + XYGamete V: 22 + XX

Gametes T have a pair of homologous chromosomes that have

different sizes, chromosomes pair XYGametes V consists of all chromosomes pairs with the same size

and homologous,

Normal Female Normal Colour blindnessFemale carrier male male

25%haemofilia

F : Tissue CultureP1: Able to obtain good characteristics that can be used

commercially(selectivity)P2: Can be conducted any time and does not need any

pollinating agents as it is carried out in the laboratory

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(F + anyP)

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Section B:

6.(a)(i) Process Y = ultrafiltration

A process wherebyF1 water and solutes from glomerulus being forced to

filter through the membrane of Bowmans capsule

F2 - by the high hydrostatic pressureF3 - forming glomerular filtrate that contains water, glucose, amino

acids, urea, mineral salts and other small molecules

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(ii) F1 - less efficient in filtration of waste products and excess waterin blood plasma

P1- as a result, urea uric acid/ creatinine / salt concentration will beincrease

P2 - increase the blood pressureF1 - use haemodialysis machine / kidney transplantF2 - to replace the function of kidney; filtrate all the waste product

and excess water.

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(b) F1 Glucose reabsorb by facilitated diffusion into blood capillaryE1 Glucose needed by our bodyF2 Acid amino reabsorb by facilated diffusionE2 Acid amino is needed for body growth / tissue repairF3 Protein is a big molecule and cannot move via membrane

plasma.E3 Protein is still circulate in blood capillary.F4 Urea is secreted substances and cannot move back to blood

capillaryE4 Water is reabsorb by osmosis and the concentrate of urea

increase.F5 Sodium ion is move back to blood capillary via active transportE5 Sodium is importance for maintain the blood pressure.

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20marks

7. (a) F1 - Height // weightE1 - continuouse variation becouse have differences very slightlyE1 Controls by environment.

F2 - Blood typeE2 discontinuouse variation /E2 - controls by genetics.

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(b) - The gene for the insulin is isolated from human pancreas cell- The bacterial plasmid is isolated (DNA found in bacteria)- The bacterial plasmid is cut by using enzyme- The enzyme used to incorporate gene for insulin production into the

plasmid- the bacteria are cultured in bioreactor

- the plasmid replicate as a bacteria divide asexually .- the bacteria can produce insuline in large quantity, purified and

isolate.

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c) F1 meiosisP1- produce varies gamet with different genetic contents;P2- through homologous chromosomes random assortment during

metaphase 1

F2- FertilizationP3- random fertilization between sperm and ovum

P4 produce zygote with varies genetic materials.

F3 crossing overP5 crossing over occurs between the homologous chromosomes

during prophase 1- result recombinants gens- produce varies gamete cells

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8.(a) y Pollen sac and pollen parental cell

y Meiosis

y Microspore/pollen

Able to link using lines/arrow correctly

Sample answer

C1

C2

C3

C4

Able to describe how pollen grains are formed in plants

y Pollen grains are male gametes (produced in the anther/pollensac

y (pollen sac) contains diploid pollen parental cell/ pollen mothercell/ microspore mother cell

y (each pollen mother cell) undergoes meiosis

y Producing 4 haploid microspores(n)

y nucleus of (every) microspore undergoes mitosis forming twonuclei

y The generative nucleus and the tube nucleus

y

Microspore with surfaces adapted for dispersion and is nowcalled pollen

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marks

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(any6)

10marks

Pollen sac Pollen parental

cell

Meiosis

microspores

Pollens


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(b)Sperm bank

y Used when the man/spouse/male suffers from low spermcount/production of weak/unhealthy sperms

y Sperms are donated and donors identity is recorded/secret

y Genetic biodata of donor and the woman recipient should matchfor successful fertilization

Artificial insemination

y Practiced by a couple when the man is sterile

y Donors sperm are injected into the womans uterusduring ovulation

y No sexual intercourse is involved

y The genetic background and health of donor is screenned

before acceptance

In vitro fertilization

y Practiced when the womans ovum cannot be fertilized due toblockage of fallopian tube

y Ovum is extracted (from the woman) and fertilized outside thebody/in Petri dish/test tube

y Fertilized ovum/zygote grows in culture medium

y Than it is implanted into the womans uterus

Surrogate mother

y Method practiced when a woman cannot be pregnant innormal way

y The zygote is obtained by invitro fertilization

y Another woman is implanted with the couple zygote

y (Surrogate mother) carries the baby only until it is born

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(any10)

10mark(20mark)


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9 (a) Based on the detail above, explain the effect on the lake if theirplanning is not managed properly.F1 - the leaching of chemical fertiliser/phosphate/nitrate from

agriculture area to the lakeE1 - Increase the fertility of the lakeE2 - Encourages eutrophication (encourage algal growth)

F2 - The growth alga prevent the light from reaching the base of thelake

E3 This reduce and prevents photosynthesis by aquatic plant.E4 Reduse the oxygent releaseE5 Aquatic plants and animals die due to lack oxygent.F3 decomposition of dead plants, animals and organic mater by

saprofitic bacteria iccureE6 This will decrease the dissolved oxygen contentF5 BOD increase the water pollutedE7 This couse the aquatic animals die.

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Any 10 10

(b) Factor + Explanation.F (Name the effect) (The phenomenon) is acid rainE1 Factors / motor vehicles / factory released large amount of

nitrogen oxydeE2 - and sulfur dioxydeE3 oxyde of nitrogen combine with water vapour (in atmosphere)

to form nitric acid.E4 sulphur dioxyde combined with water vapour (in atmosphere) to

form sulphuric acid.E5 the rain fall as the acid rain.

Effect.E1: may corrode the building

E2: acidic water couse aquatic animal died.E3: minerals in soil dissolved/washed into river.E4: siol become infertile / not suitable for plant to growth.E5: Less yield / plant become die becouse the infertile soil.E6: The ecological ballamce of ecosystem distrupt.

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1F +4E

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111115Es

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1020

marks

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