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LEAVING CERTIFICATE BIOLOGY
HIGHER LEVEL EXAM PAPER SOLUTIONS
Sample Paper 4
Section A
Question 1
a)
D: Zone of Differentiation/C: Zone of Elongation/A: Root Cap/B: Meristem 4(1) New Tissues: Zone of Differentiation/Mitosis: Meristem/Growth Regulators: Zone ofElongation/Absorbtion of water: Zone of Differentiation 4(1) (i) A: Vascular bundle/B: Air Spaces/C: Guard Cells/D: Stoma 4(1). (ii) B+D2(I). (iii)Xylem/carries water and minerals up the stem 2(1). (iii) Correct labels X+Y 2+2 Question 2
a) Dd
b)
Question 3
a)
Proteins produced by lymphocytes in the lymphatic system /to fight pathogens 2(2) Weakened form of pathogen which is inoculated into the body to induce production ofantibodies (2) Produces more antibodies/effect lasts longer/quicker response to second infection 2(1) May have side affects mmr vaccine, can cause brain damage (2) Question 4
a)
(i) Competition –organisms compete for a common resource/cattle and sheep compete for grass2(2) (ii) Organism lives on or in another living organism causing death or disease/liver fluke lives inthe bile duct of cattle or sheep 2(2) (i) fox/sheep(2), (ii) rabbits – large ears for hearing/fox – good nocturnal vision 2(2), (iii)correct graph out of phase (4) Question 5
a)
(i) DNA fragments, (ii) Thicker due to concentration of fragments of the same type, (iii) 9 3(2) (i) C (ii) his sample matches the cigarette butt sample 2(2) Adenine/Thymine/Guanine/Cytosine 4(1). ThymineorCytosine/hydrogen bonding 2(1) Question 6
a)
Carbohydrate: whole grain bread/sugar; Fat: butter, ham, cheese ice cream, Protein: cheese, hamWater soluble vitamin: Vitamin C/Orange juice 4(1) (i) fibre: whole grain bread, apple, peach, (ii) improves movement of food/cleans digestivesystem/prevents constipation 2(2) (i) a single sugar unit (2), (ii) glucose (1), test Fehling’s solution or benedict’s reagent/heat800C/Colour change blue to red 3(2) Section B
Question 7
a) (i) Transpiration (3)
(ii) Easy to see – show exact transpiration stream pathway through the plant (3) (i) Place stem in carrot (centre removed) or older stem (elder) – or cut with micro tome – cross section (ii) Place very thin sections in water.
(iii) Remove with paintbrush onto slide.
Significance: makes nucleus easy to see, also outlines plant cell wall (2) Question 8
a)
Substrate: Hydrogen peroxide (3), Starch (substrate) Product: Oxygen and water (2+1), maltase (product) Question 9
a) Amylase
Plant undergoes dormancy – no metabolic actions (6) (i) To ensure enzymes came in contact with substrate. (6) (iii) To allow time and suitable conditions of temp for the enzyme to digest the starch.
Results: Where the seeds lay all the starch had been digested: no blue-black colour wheniodine added.
Control: Control as above using boiled seeds 5(3) Section C
Question 10
a) (i) 6 CO2 + 6 H2O
(iii) Use a water bath – constant temp 25–30oC on thermostatically controlled waterbath/temperature affects rate of enzyme activity. 2(3) (iv) as conc. of CO2 increases so too does the rate until at a certain conc. the reactionbecomes saturated and rate remains constant. (3) (v) Increased light intensity increases rate. (3) (i) Artificial light provides great light intensity/longer exposure of plants to light.(6) (ii) Greater amounts of CO2 keeps photosynthetic rate at maximum. (3) Summer: Greater time of light exposure (6) Question 11
a)
(i) Male infertility = inability to produce sperm or low sperm count (3) (ii) Smoking/alcohol abuse/drug abuse stop the mentioned or hormone treatment orchange in diet. 2(3) (i) A = Testes, B = Sperm Duct, C = Prostate gland, D = Urethra, E = Penis. 5(2) Diagram to include Tail, Collar, Nucleus, Aerosome (iii) In diagram show sperm from testes sperm duct penis vagina cervix uterus (womb) (i) In vitro = fertilization outside the body/eggs removed from the ovary 2(3) (ii) A fertilized egg is implanted/in the uterus/the eight cell structure is the morula. 3(3) (iii) Progesterone: failure or drop off of progesterone/= miscarriage (6) Question 12
a)
(i) Habitat: a place where plants and animals live.
Niche: is the functional role of an organism in a community.
(ii) Aquatic habitat: salinity; current speed, wave action, O2. (2+1) (ii) Qualitative: Identifies the types of species present in a habitat. (3) Quantitative: Records numbers of each species present in a habitat. (3) Error: Human error: e.g. counting; using a transect not typical of habitat.
Changing conditions; accidental discovery; insufficient sample size. (4) (ii) 2 plants 2(1), + 2 animal 2(1), adaptation (2) (i) Spraying: results in fewer tomato flowers producing tomato fruits. (8) (ii) Spiders may develop an immunity to the mites/mite population reduced (8) due tolack of food.
(iii) autotroph: tomato plant; herbivore: spider. 2(4) Question 13
a)
(i) A chemical messenger, released into the blood system from an endocrine gland to atarget Diagram to include (outside). Diagram 0, 3, 6 Labels: Cell body, dendron, dendrites, myelin sheath, schwann cells, node of ranvier. 6(2) Correct labels 5(1) (ii) Hormone name & function (2) + (2) Question 14
a)
(i) Cell continuity refers to the fact that all cells arise from pre existing cells. (3) (ii) X = Mitosis (Asexual reproduction by cell division).
(iii) Mitosis produces 2 identical (diploid or haploid) daughter cells, geneticallyidentical. 2x(1) Meiosis produces 4 haploid daughter cells (half number), genetically different.
unicell organism like amoeba: increases number of individuals.
In multicell organisms, it produces new cells for growth and repair.
Meiosis: Allow for sexual reproduction, i.e. leads to production of gametes with haploid number of chromosomes: These combine to form a diploid zygote. 2x(2) Allows for variation leads to different combination of genes.
Cancers: are uncontrolled multiplication of abnormal cells. In this case the mitosis and the rate of reproduction of abnormal cells cannot be controlled. (2) Causes: Carcinogens: – Cigarette smoke, asbestos, UV light, A/B gama rays, RrBb Rrbb rrBb rrbbPink Pink white whiteBroad Narrow Broad Narrow (ii) Mendel’s Second Law: During gamete formation either of a pair of alleles mayreassort randomly with either of another pair. (5) case: the gene R is combined with B or b to form RB and Rb And r is combined with B or b, rB and rb are formed.
This giving 4 possible phenotypes (genotypes of offspring). 4 x (2) (i) Variations: Differences between members of species. (3) Mutation: change in amount or structure of DNA. (3) Causes: Chemicals, formaldehyde, tobacco smoke, radiation (UV). 2x(1) (ii) Evolution: is the genetic change in living organisms producing new forms of lifeover a long period. (iii) Source of evidence: Fossils: – rocks aged, older rocks less fossil/new rock morefossils/which are more specialised than predecessors/shows common ancestry.
The wing of a bat, hoof of a horse, paddle of a whale: all have the same bones/whichhave become adapted/shows common ancestry. 3x(3) Organisms retrace their ancestry during their embroyology/by examinig the fish, frog,bird and human embryo we see the existence of gill slits/showing common ancestry.
3(3) Question 15
a) (i)
w = xylem; x = phloem; (Y): ground tissue; z = root hair.
(ii) Osmosis: Nitrogen; sodium; calcium; phosphorous; potassium Use: N: produce proteins, Na: control osmotic balance, Cu: growth, P = (iii) xylem: diagram (0, 1, 3). Cell wall; Spiral (lignin); Hollow lumen All internal structures die leaving a hollow lumen in the xylem. No living cytoplasm ofjust hollow phloem: companion cells have a clear cytoplasm and posess a nucleus.
(i) Evaporation from a leaf of water through stomata. Cuticle water proof. Stomata onunder-surface. (Reduce) (ii) Root pressure, capillarity; adhesion, cohesion Adhesion: Water adheres to the moist xylem.
Cohesion: Hairs keep water molecules together. Forming a continuous column. As water evaporates the column moves up.
(ii) Excretion removal of metabolic waste.
Leaves: Loose water, O2 + CO2 through their lenticels and stomata. Water and CO2 are products of respiration. O2 is a product of photosynthesis and lost during the day,together with H2O. CO2 is a product of respiration.

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