JAMB - Biology (2021)

• 1

  One of the functions of the xylem is?

  إجابة

  (A)

  strengthening the stem
• 2

  Which of the statements below is not characteristic of wind-pollinated flowers?

  إجابة

  (C)

  The pollen grains have rough spiny surfaces
• 3

  Some of the features of an animal are scales, teeth, nares, and backbone. The animal is likely to be a?

  إجابة

  (C)

  lizard
• 4

  Choose the sequence which represents the correct order of organisms in a food chain

  إجابة

  (B)

  Grass, grasshopper, toad, snake, hawk
• 5

  Flatworms and roundworms are said to be invertebrates because?

  إجابة

  (D)

  they have no backbones
• 6

  When a Spirogyra cell is immersed in a salt solution more concentrated than its cell sap, it?

  إجابة

  (D)

  loses water and shrivels
• 7

  Which of the following is NOT regarded as a pollutant on land or in the air?

  إجابة

  (B)

  Nitrogen
• 8

  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?

  إجابة

  (D)

  30.0
• 9

  When the original king and queen of termites die, they are replaced by 

  إجابة

  (D)

  developing nymphs nurtured as secondary reproductives
• 10

  In demonstrating the importance of mineral elements in plants, the culture bottle must be darkened to?

  إجابة

  (A)

  prevent algal growth in culture solution
• 11

  In the mammalian respiratory system. exchange of gases occurs in the?

  إجابة

  (D)

  alveoli
• 12

  Aged erythrocytes are destroyed in the?

  إجابة

  (B)

  liver
• 13

  The villus in the small intestine is significant because it?

  إجابة

  (A)

  increases the surface area for absorption
• 14

  Which of the following food substances will produce a brick-red colour when warmed with Benedict's solution?

  إجابة

  (A)

  Glucose
• 15

  The blood vessel which carries blood from the alimentary canal to the liver is the?

  إجابة

  (C)

  hepatic portal vein
• 16

  Which of the following is TRUE of the process of conjugation in Paramecium?

  إجابة

  (D)

  Each micronucleus divides twice
• 17

  People who suck petrol with their mouths run the risk of increasing in their blood the concentration of

  إجابة

  (B)

  lead
• 18

  Which of the following is a measure for the control of bilharzia?

  إجابة

  (B)

  Application of molluscicides in water bodies
• 19

  The appendicular skeleton is composed of the pectoral girdle?

  إجابة

  (A)

  pelvic girdle, fore and hind limbs
• 20

  A freshwater plant such as water lily can solve the problem of buoyancy by the possession of?

  إجابة

  (A)

  aerenchyma tissues
• 21

  The correct sequence for the perception of smell in mammals is?

  إجابة

  (D)

  dissolved chemicals --> sensory cells --> olfactory nerve --> brain
• 22

  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? 

  إجابة

  (B)

  I and III
• 23

  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?

  إجابة

  (C)

  46%
• 24

  When a marine fish was taken from the ocean and put in a tank of fresh water, it died after a short period because? 

  إجابة

  (B)

  the body cells of the fish swelled and burst as a result of the hypotonic fresh water
• 25

  If a DNA strand has a base sequence TCA, its complementary strand must be?

  إجابة

  (D)

  AGT
• 26

  The two key cations involved in the action potential of nervous transmissions are?

  إجابة

  (C)

  Na+ and K+
• 27

  I. Rattus rattus. Il. Agama agama III. Bufo regularis IV. Tilapia zillii
  The order of evolutionary advancement of the above vertebrates is?

  إجابة

  (D)

  IV, III, II, I
• 28

  Which of the following produces both hormones and enzymes?

  إجابة

  (B)

  Pancreas
• 29

  The correct sequence of the movement of urea during urine formation is?

  إجابة

  (B)

  glomerulus -> Bowman's capsule -> convoluted tubule -> Henle's loop -> convoluted tubule -> collecting tubule
• 30

  The order of passage of food in the digestive system is

  إجابة

  (A)

  ileum --> caecum ->large intestine -> rectum
• 31

  Mass of a crucible = 10g,

  Mass of a crucible and soil before heating =29g

  Mass of a crucible and soil after heating = 18g

  From the information above, determine the percentage of water in the given soil sample?

  إجابة

  (D)

  60%
• 32

  I. Stomata --> Spirogyra

  II. Alveoli --> Earthworm

  III. Malpighian tubule -> Mammal

  IV. Contractile vacuole -> Protozoa

  Which of the above structures is correctly matched with the organisms in which it is found?

  إجابة

  (C)

  IV
• 33

  The sequence of the one-way gaseous exchange mechanism in a fish is?

  إجابة

  (B)

  mouth -> gills > operculum
• 34

  Which of the following is true in blood transfusion?

  إجابة

  (A)

  A person of blood group AB can donate blood only to another person of blood group AB
• 35

  The plants that grow in deserts or very dry areas are referred to as?

  إجابة

  (C)

  xerophytes