- A potato cylinder measuring 100mm was placed in a concentrated salt solution for 30 minutes. Describe its texture and appearance after 30 minutes.
It becomes soft, flaccid and also shrinks in size
- What is the function of carnassial teeth
carnassial teeth Molar and premolar teeth modified for shearing flesh by having cusps with sharp cutting edges. They are typical of animals of the order Carnivora (e.g. tigers, wolves), in which they are the first molars in the lower jaw and the last premolars in the upper.
- People can die when they inhale gases from burning charcoal in poorly ventilated rooms. What compound is formed in the human body that leads to such deaths
- Which vitamin is synthesized by bacteria in the human colon? state it's function
Vitamin K is a fat-soluble vitamin that is most well known for the important role it plays in blood clotting. However, vitamin K is also absolutely essential to building strong bones, preventing heart disease, and crucial part of other bodily processes.
- State two examples of mutagens.
an agent, such as radiation or a chemical substance, that causes genetic mutation.
eg. bromine, sodium azide, psoralen, benzene, x-rays, gamma rays, alpha particles, ultraviolet radiation
- State two functions of the enzyme thrombokinase in blood clotting process.
It is a complex enzyme that is found in brain, lung, and other tissues and especially in blood platelets and that functions in the conversion of prothrombin to thrombin in the clotting of blood
- Name the element obtained from insects by insectivorous plants
- What is meant by non-disjunction?
Nondisjunction is the failure of homologous chromosomes or sister chromatids to separate properly during cell division.
- Give ONE example of continuous variations in humans.
Height, skin color, weight
- State the functions of ear ossicles
The function of the ossicles is to transmit (and amplify) vibrations of the tympanum across the middle ear to the oval window, which transfers them to the inner ear
- State TWO functions of the substance secreted by sebaceous glands
Sebum waterproofs and lubricates the skin and hair of mammals.
- What is homeostasis?
The tendency of the body to seek and maintain a condition of balance or equilibrium within its internal environment, even when faced with external changes. A simple example of homeostasis is the body's ability to maintain an internal temperature around 98.6 degrees Fahrenheit, whatever the temperature outside.
In an experiment, the pituitary gland of a rat was removed.
State giving a reason, the effect this will have on the quantity of urine produced by the rat.
The amount of urine will increase, to large amounts of diluted urine.
Function of the pituitary gland is that it secretes ADH(Antidiuretic) hormone which decreases urine production. (It causes more water filtered by the kidneys to be returned to the blood. This reduces the amount of urine.)
- Distinguish between parthenogenesis and parthenocarpy
parthenogenesis: reproduction from an ovum without fertilization, especially as a normal process in some invertebrates and lower plants.
parthenocarpy: the development of a fruit without prior fertilization.
- In view of modern evolution , explain why Lamarkian theory is unacceptable.
Acquired characteristics are not passed to the next generation..or not inherited...
- Explain how the Erythrocytes are adapted to perform their functions.
Erythrocites also known as Red blood cells have adaptations that make them suitable for this: they contain haemoglobin - a red protein that combines with oxygen. they have no nucleus so they can contain more haemoglobin. they are small and flexible so that they can fit through narrow blood vessels.
- Distinguish between Homologous and Analogous structures
Homologous structures Analogous structures Similar in anatomy Dissimilar in anatomy Doing dissimilar functions Doing similar functions Develop in related animals Develop in unrelated animals Inherited from a common ancestor Not inherited from common ancestor Similar developmental pattern Developmental pattern is not similar Similar structure and Origin Dissimilar in structure and origin