3.1 Name the process represented by the diagrams above - NSC Life Sciences - Question 3 - 2017 - Paper 2

1. During meiosis, haploid cells are produced, which contain half of the original number of chromosomes.
2. Homologous chromosomes separate and move to opposite poles during the stages of meiosis.

Phase C is labelled Anaphase I, and phase D is labelled Telophase I.

Between 1995 and 1998, the percentage of resistant insects increased significantly from 0.15% to 99.1%. Conversely, the percentage of non-resistant insects decreased from 99.85% to 0.9%.

Natural selection led to insecticide resistance in this population through the following steps:

1. Variation existed within the insect population; some insects were resistant to the insecticide, while others were not.
2. When the insecticide was applied, it resulted in the death of a large number of non-resistant insects.
3. The resistant insects survived and were able to reproduce, passing on the gene for resistance to their offspring.
4. Over time, the proportion of resistant insects increased as the non-resistant insects decreased due to the selective pressure of the insecticide.

The evolutionary process illustrated is Speciation through geographic isolation.

Species B evolved from the original population of salamanders as follows:

1. The original population became separated into two sub-populations by the central valley.
2. Each sub-population was exposed to different environmental conditions, leading to distinct evolutionary pressures.
3. Natural selection acted independently within the two sub-populations, resulting in genetic differences.
4. If interbreeding were to occur, the two populations would recognize each other as different species, hence resulting in the formation of Species B.

This process is not an example of punctuated equilibrium because:

1. Punctuated equilibrium suggests that evolution occurs in short bursts of rapid change followed by long periods of stability.
2. In this case, the evolution of the species occurred gradually over a long period due to constant natural selection pressures in different environments.

The number of the skull belonging to the pelvis (a) is 3.

The LETTER of the pelvis is B and the NUMBER of the skull is 1.

Skull 3 has the most developed canines.

Mitochondrial DNA analysis supports the "Out of Africa" hypothesis by showing that mitochondrial DNA in modern humans can be traced back to a common ancestor in Africa.

1. The similarities in mitochondrial DNA suggest that all modern humans share a common maternal lineage originating from Africa.
2. This evidence implies that modern humans migrated from Africa and then spread across the earth.