Recombination is the method by which organisms can randomly assort their genotypes amongst each other to create offspring with a different haplotype than either of its parents. This can be done by either copying sequences from one homologous chromosome to another (no physical exchange) or crossing over (physical exchange.
Crossing over is a mechanism in eukaryotes by which recombination can occur, in which the two homologous chromosomes contributed by both parents literally cross over and break at certain points to exchange certain sections of the chromosomes amongst each together.
Self fertilizing organisms typically do not produce offspring that are genetically identical. However, this has an inbreeding effect on its offspring, since it is recombining from the same genotype and so has a higher chance of producing homozygous offspring. This is very detrimental for mammals and some eukaryotes, but in some other organisms such as bacteria, homozygosity is typically not an issue.
When a volcano erupts , a mixture of gases and particles is released into the air . The cooling influence of an individual volcano will dominate for the period immediately after the eruption but the warming impact will last much longer.
Answer: Option C.
Tundra
Explanation:
Tundra is a biome that has low Precipitation. Precipitation is a form of water that fall from the atmosphere to the Earth surface. Which could be inform of snow, sleet e.t.c.
Tundra is the coldest of all types of biomes. It has low temperature, little precipitation,low nutrients. It is located near the north Pole of the Earth. It is characterized by permafrost, permanent frozen layer on its surface.
Answer:
a Anaphase I
b Metaphase I
c Telophase I
d Anaphase II
e Prophase I
f Telophase II
Explanation:
Prophase I begins after the DNA has been duplicated, as shown in picture e. The chromosomes are condensed, and also visible, which is apparent in picture e.
The next stage is called Metaphase I, in which the pairs of homologous chromosomes align at The the centre of the cell and the spindle fibres attach, as shown in picture b.
The pairs of chromosomes are pulled apart to opposite poles of the cell by the spindle fibres., as shown in picture a. This stage is called Anaphase I.
Then, a process called Telophase I occurs, when the cell divides into two daughter cells. One of these cells is shown in picture c.
Picture d shows the stage Anaphase II, where the spindle has attached and the chromatids are pulled to the opposite poles of the cell.
The final picture left is picture f, which shows the daughter cell at the end of meiosis II, where the nuclear envelope is reforming, as in telophase II.
