The mesophyll layer of a leaf consists of
- A. wax and cutin
- B. cells with lignified walls
- C. irregularly shaped collenchyma cells.
- D. photosynthetic parenchyma cells.
Which of the following cycles involves the process of precipitation and transpiration?
- A. Water cycle
- B. Carbon cycle
- C. Nitrogen cycle
- D. Oxygen cycle
Which of the following processes removes carbon from the atmosphere?
- A. Putrefaction
- B. Photosynthesis
- C. Volcanic eruption
- D. Burning of fuels
A seed of a flowering plant can best be described as
- A. radicle and plumule
- B. the developed ovule
- C. the embryo and endosperm
- D. developed ovary
Spectacles with convex lenses correct long-sightedness by
- A. converging the light rays before they enter the eye.
- B. diverging the light rays before they enter the eye.
- C. reducing light intensity before it enters the eye
- D. increasing light intensity before it enters the eye
The part of the ear which contains nerve cells sensitive to sound vibrations is the
- A. cochlea
- B. ampulla
- C. tympanum
- D. malleus
The reason why hospitals use saline solutions as drip instead of water is
- A. because salt is a preservative
- B. to prevent contamination of the body
- C. to maintain the composition of the body fluids
- D. to increase the number of blood cells
What physiological term can he used to
describe the regulation of the body
temperature of the lizard? ‘
- A. Homeostasis
- B. Homoithermy
- C. Poikilothermy
- D. Osmoregulation
Which of the statements below is valid?
- A. The bird’s blood was always warmer than that of the lizard
- B. The body temperature of the bird varied less than that of the lizard during changes in environmental temperature
- C. The body temperature of the bird remained constant despite changes in environmental temperature
- D. The body temperature of the lizard was always close to that of the environmental temperature
Which of the following organisms have kidney as their excretory organ?
- A. Fishes, amphibians, birds, man.
- B. Fishes, amphibians, annelids, insects
- C. Fishes, reptiles, birds, tapeworms
- D. Fishes, protozoans, amphibians, man
A group of rats placed in an air-tight box for some hours died because they
- A. breathed in air containing nitrogen.
- B. produced carbon dioxide
- C. ran short of energy
- D. used up the available oxygen
Which of the following features is not characteristic of arteries? Arteries
- A. possess valves at intervals throughout their length
- B. have thick, muscular and elastic walls
- C. carry blood away from the heart
- D. transport oxygenated blood with the exception of the pulmonary artery
The reason why the flow of blood through the capillaries is very slow is
- A. because the walls of capillaries are very thin
- B. to avoid high blood pressure
- C. to ensure that the individual does not get dizzy
- D. to allow adequate time for exchange of materials.
Which of the following structures is not a skeletal material?
- A. Chitin
- B. Cartilage
- C. Bone
- D. Muscle
The longest bone in the body is the
- A. humerus
- B. femur
- C. scapula
- D. tibia
The following statements about mitotic cell division are correct except that
- A. it occurs only in young cells
- B. it occurs In somatic cells
- C. the chromosome number of the daughter cell is the same as that of the parent
- D. the genetic composition of the mother cell is the same as that of the daughter cell.
Two organelles directly involved in mitotic cell division are
- A. nucleus and mitochondrion
- B. ribosome and nucleus.
- C. centriole and Golgi apparatus
- D. nucleus and centriole
The curvature movement of plants in response to the stimulus of water is called
- A. hydrotropism
- B. geotropism
- C. phototropism
- D. thigmotropism
Red blood cells were found to have burst open after being placed in distilled water for an hour. This phenomenon is known as
- A. plasmolysis
- B. diffusion
- C. haemolysis
- D. wilting
In plant cells the role of the membrane is played by the
- A. nucleolus
- B. cell wall
- C. cytoplasm
- D. mitochondrion
The experiment above is used to demonstrate the process of
- A. transpiration
- B. water culture
- C. diffusion
- D. osmosis