Biology 2004 Jamb Examination

The correct option is D. produces short-term changes.

Explanation: Nervous control produces quick, short-term changes by transmitting electrical impulses through specific pathways (nerves), while hormonal control typically involves slower processes that result in longer-lasting effects through chemical transmission via the bloodstream.

The correct option is C. the same egg and sperm.

Explanation: Identical twins are formed when a single fertilized egg (from the same egg and sperm) splits into two embryos. This means they share the exact same genetic material. In contrast, fraternal twins come from two different eggs fertilized by two different sperms, and they are genetically similar to regular siblings.

The correct option is A. DNA analysis.

Explanation: DNA analysis is the most accurate method for resolving paternity disputes because it compares the genetic material of the child with that of the potential father. DNA is unique to each individual (except in identical twins), making this method highly reliable for determining biological relationships.

A. X-and Y-chromosomes

Sex-linked genes are located on the X and Y chromosomes. These chromosomes determine the sex of an individual and carry genes related to sex characteristics as well as other traits. The X chromosome carries many genes that are not related to sex determination, while the Y chromosome primarily carries genes responsible for male sex characteristics.

B. pink

In a Mendelian cross of red and white varieties of the four o'clock plant, the F1 generation exhibits incomplete dominance, where the flowers are pink. This is because the red and white alleles blend together to produce a pink phenotype in the heterozygous condition.

A. survive in various environmental conditions

Insects are considered the most successful among invertebrates due to their ability to survive in a wide range of environmental conditions. They have adapted to diverse habitats, from deserts to rainforests, which has contributed to their success and diversity. While their exoskeletons, ability to change forms, and wings for flight are important adaptations, their overall adaptability to different environments is a key factor in their success.

D. algae, liverworts and mosses.

The absence of special food and water-conducting systems (vascular tissues) in algae, liverworts, and mosses restricts their body size. These organisms rely on diffusion for nutrient and water transport, which limits their growth compared to vascular plants that have specialized tissues for these functions.

The correct option is A. have sebaceous glands.

Explanation: While mammals are warm-blooded, have teeth, and possess lungs, these traits are not unique to mammals as they are also found in other animal groups. The presence of sebaceous glands, however, is a peculiar characteristic that is unique to mammals. These glands produce sebum, an oily substance that helps to lubricate and protect the skin and hair.

B. cells

Explanation: Rods are specialized photoreceptor cells in the retina that are responsible for vision in low light conditions. They are a type of cell rather than an organ, system, or tissue.

C. wriggler

The larval stage of a mosquito is commonly referred to as a wriggler. Caterpillar, maggot, and grub are terms used for the larval stages of other insects or organisms.