When large numbers of organisms share limited space and resources the result is
- A. immigration
- B. commensalism
- C. symbiosis
- D. extinction
- E. competition
Increasing specialization of structure and function among animals of the same class and order for survival in new and different environments is called
- A. adaptive radiation
- B. phylogeny
- C. homology
- D. analogy
- E. ontogeny
A man with blood group A (TAP) married a woman with blood group O (pp). Which of the following is the
probable ratio of the blood groups of the offspring?
- A. 1:1
- B. 3:1
- C. 2:1:1
- D. 1:2:1
- E. 4:1
If a cross is made between a pure-breeding red flowered plant and a pure-breeding white flowered plant
where R is dominant for red flower and r is recessive for white, the most likely result of F generation will be
- A. 75% red flowers and 25% white flowers
- B. all red flowers
- C. 75% white flowers and 25% red flowers
- D. 50% red flowers and 50% white flowers
- E. all white flowers
The haploid number of chromosomes in man is
- A. 48
- B. 46
- C. 42
- D. 24
- E. 23
Which of the following best describes the homologous chromosomes? They are
- A. a product of the division of a chromosome
- B. two identical chromosomes from each parent
- C. chromosomes arranged on spindle fibres during cell division
- D. daughter chromatides formed during meiotic division
- E. chromosomes during telophase of mitotic division
Which of the following is not a constituent of DNA?
- A. Purine
- B. Phosphate
- C. Cystocine
- D. Deoxyribose
- E. Uracil.
Assuming that ‘A’ is gene for normal skin and it is dominant, while ‘a’ is gene for albinism and it is recessive,
what is the likely genotype of a couple which had 50% normal and 50% albinos?
- A. AA,Aa
- B. AA,aa
- C. Aa, Aa
- D. Aa, aa
- E. AA,AA
Which of the following major ideas were proved by Gregor Mendel?
- A. There is a tendency among organisms `to increase rapidly in number if conditions are favourable
- B. There is a struggle for existence among a very large number of offspring
- C. Nature selects organisms which will survive to produce their kind
- D. All species exhibit structural and functional variations
- E. Characteristics of an organism are controlled by genes occurring in pairs
During blood transfusion, agglutination may occur as a result of the reaction between
- A. similar antigens and antibodies
- B. contrasting antigens and antibodies
- C. two different antigens
- D. two different antibodies
- E. white blood cells from the two individuals.
Which of the following .is not part of the objectives of conservation of natural resources?
- A. To eliminate wild animals in order to enable other plants and animals survive
- B. To use our resources on sustained yield basis
- C. To guard against indiscriminate killing of plants and animals
- D. To guard against the extinction and exhaustion o natural resources
- E. To protect the environment
Which of the following steps would not be taken to protect or conserve fishing grounds from over-exploitation?
- A. . Use of nets with all sizes of mesh
- B. Use of nets with a particular mesh size
- C. Ban on harvesting of some species
- D. Regulating the size of ships allowed into fishing grounds
- E. Limiting the period of fishing in the waters
A constituent of the exhaust gases of motor vehicles which causes serious air pollution is
- A. water vapour
- B. carbondioxide
- C. carbon monoxide
- D. oxygen
- E. ozone
The vector of the malarial parasite is the
- A. male Anopheles
- B. female Culex
- C. male Culex
- D. female Anopheles
- E. female Aedes
Which of the following are not causative organisms of plant diseases?
- A. Fungi
- B. Viruses
- C. Bacteria
- D. Nematodes
- E. Cercariae
The causative organism of sleeping sickness is the?
- A. Trypanosome
- B. Plasmodium
- C. Vibrio bacterium
- D. penicillin
- E. tsetse fly
Which of the following statements is not true of a climax vegetation? It
- A. is an ecological phenomenon
- B. is a stable community
- C. eliminates competition
- D. results from succession
- E. involves the colonization of a habitat
Terrestrial organisms which are capable of maintaining their body temperature constant within fairly close
limits are referred to as
- A. thermoclines
- B. homotherms
- C. poikilotherms
- D. eurytherms
- E. stenotherms
Which of the following factors is not associated with aquatic habitat?
- A. Temperature
- B. Light intensity
- C. Humidity
- D. Turbidity
- E. Wave action
Which of the following is not a characteristic feature of tropical rain-forest habitat?
- A. Trees with longer boles than those in Savannah
- B. Fewer canopy strata than the savannah
- C. Many more trees and climbers than savannah
- D. Plenty of leaf litter on the ground
- E. More diverse communities than the savannah
Which of the following does not contribute to the biomass in an ecosystem?
- A. Producers
- B. Food chains
- C. Consumers
- D. Micro-organisms
- E. Saprophytes