B. Because of the presence of hydrogen sulphide in Brass, it combines with oxygen in air and form water, evaporates. So remained sulphide is colourless in air .So Brass gets discoloured in the air.
Answer
Use Mitosis to divide and create daughter cells.
Explanations
Single-celled organisms use mitosis to reproduce. Both growth and reproduction in unicellular organisms are mutually inclusive. When the cell’s volume grows, the ratio of surface area to volume decreases creating challenges in acquisition of nutrients because there will be too much cytoplasm for a given amount of nuclear material , thus the cell divides by mitosis to reproduce daughter cells and the process begins again.
Mitosis
Involves one cell division?
Results in two daughter cells
Results in diploid? daughter cells? (chromosome? number remains the same as parent cell)
Daughter cells are genetically identical
Occurs in all organisms except viruses
Creates all body cells (somatic?) apart from the germ cells? (eggs and sperm)
Prophase is much shorter
No recombination/crossing over occurs in prophase.
In metaphase individual chromosomes (pairs of chromatids) line up along the equator.
During anaphase the sister chromatids are separated to opposite poles.
Meiosis
Involves two successive cell divisions
Results in four daughter cells
Results in haploid? daughter cells (chromosome number is halved from the parent cell)
Daughter cells are genetically different
Occurs only in animals, plants and fungi
Creates germ cells (eggs and sperm) only
Prophase I takes much longer
Involves recombination/crossing over of chromosomes in prophase I
In metaphase I pairs of chromosomes line up along the equator.
During anaphase I the sister chromatids move together to the same pole.
During anaphase II the sister chromatids are separated to opposite poles.
Similarities
Mitosis
Diploid parent cell
Consists of interphase, prophase, metaphase, anaphase and telophase
In metaphase individual chromosomes (pairs of chromatids) line up along the equator.
During anaphase the sister chromatids are separated to opposite poles.
Ends with cytokinesis.
Meiosis
Diploid parent cell
Consists of interphase, prophase, metaphase, anaphase and telophase (but twice!)
In metaphase II individual chromosomes (pairs of chromatids) line up along the equator.
During anaphase II the sister chromatids are separated to opposite poles.
Ends with cytokinesis.
Answer:
Gravitational attraction provides the centripetal force needed to keep planets in orbit around the Sun and all types of satellite in orbit around the Earth. This means gravity makes the Moon accelerate all the time, even though its speed remains constant.
Explanation:
Since two females are unable to reproduce. Therefore, if only two females are still alive, the species will become extinct.