ROUTE TO NECTABIOLOGY JOINT EXAMINATION

FORM FOURJULY 2019

INSTRUCTIONS:1. This paper consists of section A, B and C.2. Answer ALL questions in section A and B and ONE (01) question from section C.3. Read each question carefully before you starting answering it.4. Except for diagrams which must be drawn in pencil, all writings should be in blue/black ink or ball

point pen.SECTION A( 20 marks).

1. For each of the items (i)-(x) choose the correct answer from among the given alternatives and write its letter in the boxes provided beside the item number.

i) One of the most efficient way of preventing STI’s isa. Protected sexb. Take balanced dietc. Delaying sex

d. Avoiding sharing of razor blades

e. Keeping the environment cleanii) Asha wanted to differentiate an animal cell from a plant cell. Which one is the most correct?

A plant cell has a ………………. which is absent in animal cells.a. Cell membraneb. Nucleusc. Chloroplast

d. Centriolee. Mitochondrion

iii) A form three student had a problem of dislocation in the knee. Which of the following tissues were injured seriously?a. Cartilageb. Tendonc. Muscle

d. Synovial membranee. Ligament

iv) The protein food entered the duodenum without being digested. Which part of the digestive system has failed to perform its work?a. Stomach b. Colon c. Mouth d. Oesophagus e. Ileum

v) Amoeba is an organism in the Kingdom …………………a. Animalia b. Plantae c. Protoctista d. Fungi e. Monera

vi) Farmers are advised to plant maize together with plants such as beans or peas because, nitrogen fixing bacteria in their roots help toa. convert atmospheric nitrogenb. convert soil nitratesc. prevent soil from drying out

d. increase nitrogen content in he soil

e. increase nitrogen content in the atmosphere

vii) A scientist wanted to observe male gametes of a particular flower. In which of the following parts are the gametes present?a. Ovary b. Filament c. Anther d. Style e. Stigma

viii) When you move from bright sunshine into a dark room.#, which of the following changes occurs?a. Pupil becomes larger. c. Ciliary muscles relaxb. Lens becomes thicker d. Eyes become blind e. Eyes become tired

ix) If menstruation occurs on days 4 to 9 of a month, what would be the date of ovulation in a menstruation cycle of 28 days?

a. 14th b. 17th c. 21st d. 22nd e. 28th

(x) Which part of a seed grows into the root system of a plant?a. Plumule

b. Radical c. Cotyledon

d.Micropy

2.Match the phrases in List A with the responses in List B by writing the letter of the correct response from List B beside the item number of List A in your answer sheetLIST A LIST B(i) The small wings of ostriches and penguins(ii) Gradual change from simple to complex over long

duration of time(iii) Long necked and short necked giraffe(iv) Wings of bat and grasshopper(v) Study of fossils records(vi) Universe has no origin(vii) Formation of new species(viii) An English naturalist based on theory of evolution by

natural selection(ix) Forelimbs of goat, fore limbs of human being and wings

of bird(x) Life on earth originated from elsewhere

A. Homologous structureB. Analogous structureC. Use and disuse of organsD. Vestigial organsE. Vestibular organsF. SpeciationsG. Special creationH. Parent rockI. PaleontologyJ. Steady state theoryK. Cosmozoan theoryL. OriginM. EvolutionN. DarwinO. Lamarck

SECTION B(60 marks)All questions carry 8 marks except question three (3) and nine (9) which carry 6 marks

3.(a) Mention the four (4) taste receptors of the tongue.(b) Explain the following:

(i) it is difficult to detect the smell of substances when we are suffering from cold(ii) it is impossible to detect any kind of taste under the lower surface of the human tongue

(c) (i) The diagram (fig. 1) below shows the direction of growth of potted seedling near a window in a laboratory

Fig. 1A young plant shoot

Side Side

Light

Give explanation for the observable phenomenon.

4. (a) What is the similarity in terms of growth shown by insects and amphibians.(b) Study the diagram below and then answer questions which follows:

(i) Identify the organism (x) by its common name.(ii) Label parts a – d.(iii) State the habitat of the animal x.(iv) Classify animal x up to class level.(v) State any four (4) adaptations of animal x to its mode of life.

5.(a) (i) name three muscles found in mammals(ii) which one of the muscles named in (a) (i) is voluntary?(b) name the functions of the following components of the skeleton

(i) Skull(ii) Ribs(iii) Vertebral column(iv) Pelvic girdle

6. (a) (i) Define the terms“ food chain and food web .(ii) We hardly have more than six trophic levels; explain.

(b) Mention any two (2) hormones which deals with Osmoregulation in human being.(c) Study the diagram below:

Fig. 2 Org

Root

stem

Fig. 3 Legumi

(i) Give the name of micro-organism which leaves in the swellings indicated.(ii) What is the specific name which describe the relationship between a plant and the micro-

organism.(iii) What the role of micro-organism to the plant.

7. (a) (i)Draw a diagram of a human body showing endocrine glands and then name two (2) glands.

(ii) State the function of one (1) hormone produced by each gland.

(b)(i) Define the term homeostasis(ii) Briefly explain how mammals are able to keep glucose at a constant level in their bodies

8.(a) Define the following terms:(i) Inbreeding(ii) Out breeding(iii) Test cross(iv) Backcross

(b) What is the importance of each practice above in (a)?

(c) (i) A woman with a normal skin colour was married to a man with normal skin colour. They gave birth to three children; one of them was an albino. Give probable genotype for the parents(ii) Why parents with normal skin colour give birth to the albino?

(iii) If an albino man marries a carrier woman, what is the probability of getting an albino child?9. (a) Name any four differences between aerobic and anaerobic respiration(b)Give four reasons why is better to breathe through nose than through mouth?

10. (a) Give the meaning of osmosis and diffusion(b) Briefly explain how the following illustrate osmosis

(i) Shrinking of a cell when immersed in a high concentrated solution(ii) Bursting of a red blood cell when immersed in dilute solution

SECTION C (20marks)11. Explain six factors which contribute to irresponsible sexual behavior among young people and their effect in the community.

12. (a) Define accommodation with reference to the mammalian eye.(b) Describe the mechanism of hearing

13. Write an essay of al least two pages using the following guidelinesa) Meaning of seed dormancyb) Four causes of seed dormancyc) Four ways of breaking seed dormancyd) Three importance of seed dormancy