The 'Haversian canal' in compact bone contains: MCQ with Answer and Explanation

Explanation:
Robert Brown, a Scottish botanist, discovered the nucleus in 1831 while studying orchid cells under a microscope. He named it 'nucleus'. Hooke discovered cells, Leeuwenhoek observed living cells, Schleiden proposed that all plants are made of cells. Brown's discovery was crucial for understanding cell structure and function.

Explanation:
Cloning produces genetically identical copies of an organism or cell. In animals, somatic cell nuclear transfer (like Dolly the sheep) is used. Plant cloning occurs via vegetative propagation or tissue culture. Hybridization combines different genomes; mutation breeding induces mutations; cross breeding involves mating. Cloning has applications in therapeutics, conservation, and agriculture.

Explanation:
Evolution, at its most fundamental genetic level, is defined as the change in the frequency of alleles within a population over successive generations. Speciation is the evolutionary process by which populations evolve to become distinct, reproductively isolated species. Evolution does not have a predetermined goal or direction towards complexity; it simply results in adaptation to the current environment, which can sometimes lead to simpler forms (like parasites losing complex structures). Thus, statements 1 and 2 are correct.