If a DNA strand has a base sequence TCA, its complementary strand must be?
- A. ATG
- B. TAG
- C. GAT
- D. AGT
When a marine fish was taken from the ocean and put in a tank of fresh water, it died after a short period because?
- A. the tank was too small compared to the large-ocean
- B. the body cells of the fish swelled and burst as a result of the hypotonic fresh water
- C. the body cells of the fish shrank as their sap was hypertonic to the freshwater
- D. there was no food in the tank, so the fish starved
The number of plant species obtained from a population study of a garden is as follows: Guinea grass (15), Ipomoea spp (5), Sida spp (7) and Imperata spp (23)
What is the percentage of occurrence of Imperata spp?
- A. 35%
- B. 16%
- C. 46%
- D. 23%
I. High birth rate and high immigration rate
II. Low birth rate and high immigration rate
III. Low mortality rate and low emigration rate
IV. High mortality rate and high emigration rate.
Which combination of the above can cause rapid over-crowding in climax biotic communities and human settlements?
- A. II and III
- B. I and III
- C. I and IV
- D. I and II
The correct sequence for the perception of smell in mammals is?
- A. chemicals --> olfactory nerve endings --> brain
- B. dissolved chemicals --> nasal sensory cells --> brain
- C. chemicals --> mucus membrane sensory cells --> brain
- D. dissolved chemicals --> sensory cells --> olfactory nerve --> brain
A freshwater plant such as water lily can solve the problem of buoyancy by the possession of?
- A. aerenchyma tissues
- B. dissected leaves
- C. thin cell walls of the epidermis
- D. water-repelling epidermis
The appendicular skeleton is composed of the pectoral girdle?
- A. pelvic girdle, fore and hind limbs
- B. pelvic girdle and fore limbs
- C. lumbar vertebrae and pelvic girdle
- D. lumbar vertebrae, fore and hind limbs
Which of the following is a measure for the control of bilharzia?
- A. Cutting low bushes around homes
- B. Application of molluscicides in water bodies
- C. Screening windows and doors with mosquito nets
- D. Application of herbicides in water bodies
People who suck petrol with their mouths run the risk of increasing in their blood the concentration of
- A. iron
- B. lead
- C. calcium
- D. magnesium
Which of the following is TRUE of the process of conjugation in Paramecium?
- A. Micronucleus disintegrates
- B. Each ex-conjugant divides only once
- C. Macro nucleus undergoes division
- D. Each micronucleus divides twice
The blood vessel which carries blood from the alimentary canal to the liver is the?
- A. hepatic artery
- B. hepatic vein
- C. hepatic portal vein
- D. mesenteric artery
Which of the following food substances will produce a brick-red colour when warmed with Benedict’s solution?
- A. Glucose
- B. Starch
- C. Egg White
- D. Maltose
The villus in the small intestine is significant because it?
- A. increases the surface area for absorption
- B. increases the surface area for digestion
- C. assists in mixing digested food
- D. assists in filtering undigested food
(a)(i) State the agricultural classification of specimens M and N.
(ii) What advantage does the cultivation of specimen M have over the cultivation of specimen N?
(b) State (i) the main classes of food in each of Specimens M and N. (i) the functions of the food classes named in 4(b)(i) above.
(c)(i) Describe the state of specimens M and N.
(ii) Name the pest responsible for the state of specimens M and N.
(iii) State the phylum and class of the pest with reasons.
(iv) Name two other crops which tne pest infests.
(d)i) State three adaptive features of the pest to its mode of life.
(ii) State four ways of preventing the activity of the named pest.
(e) State two other pests that can infest specimens M and N
Aged erythrocytes are destroyed in the?
- A. pancreas
- B. liver
- C. lymph nodes
- D. kidney
In the mammalian respiratory system. exchange of gases occurs in the?
- A. lungs
- B. bronchi
- C. bronchioles
- D. alveoli
Study specimens C, D, E, F,G and H carefully and use them to answer questions 2a to 2c
(a) Name the fruit types of specimens C,D,E,F.G, and H.
(ii) identify the type or placentation found in 2. C, D, E, F, G and H.
(iii) Describe briefly how specimen D is dispersed.
(c) in a tabular form state four structural differences between specimens G and H.
(a)(I)Name the organisms to which specimens A and B belong.
(ii)) State the habitats of the organisms named n 1(a)) above.
(b) State how the structure of specimens A and B adapt tne organisms to their mode of life.
(c)(i) Outline one difference. (ii) two similarities between specimens A ana B.
(d) Make drawing 8- 10 cm long of specimen B and label fully.
In demonstrating the importance of mineral elements in plants, the culture bottle must be darkened to?
- A. prevent algal growth in culture solution
- B. allow root growth
- C. prevent breakdown of mineral elements
- D. prevents photosynthesis in the root
When the original king and queen of termites die, they are replaced by
- A. the king and queen of another colony
- B. some adult reproductives from the same colony
- C. some adult workers which are specially fed to breed
- D. developing nymphs nurtured as secondary reproductives
The initial volume of water poured into a bag of dry soil was 50ml and the amount that drained through was 35mI. The percentage water content of the fully soaked soil is therefore?
- A. 46.7
- B. 25.0
- C. 20.0
- D. 30.0