When is the Earth said to be at perihelion?

Answer: a) hybridization of species, specifically parasites

Explanation:

Hybrid speciation is a kind of speciation that is caused by reproductive isolation from the parent species. In this the hybridization occurs between the two different species which leads to the formation of new species.

The hybrid formed because of the hybridization of the species that belong to the same genus called as interspecific hybrids and those formed between different sub-species are called as intra-specific hybrids.

Here, in the given situation, the hybridization of the different species of parasites due to geographical distribution of parasite due to global trade has resulted which is responsible for co-infections.

Answer:

positive: laws and regulations reforestation habitat restoration

negative: erosion deforestation desertification urbanization

Explanation:

Answer:

Positive impacts:

Reforestation

Laws and regulations

Habitat restoration

Negative impacts:

Desertification

Erosion

Urbanization

Deforestation

Explanation:

Picture above are the correct answers ^^

i. Using fossil evidences

ii. Similar rock lithologies at the edges of continent

iii. Climate clues

iv. Fitting of the continents into a puzzle

v. Sea floor spreading

Explanation:

Pangea was a super-continent on the earth which formed about 330 million years ago during the Paleozoic and began breaking up during the early Mesozoic, about 175 million years ago.

Most of the present day continents formed as a result of the separation of the Pangea in the early Mesozoic.

The first scientist to propose the existence of this super-continent was Alfred Wegener in 1912. He suggested the continental drift hypothesis to explain the separation of the land masses.

Today, the theory has been revised to the theory of plate tectonics which provides a better mechanism to understand the drifting of the continents.

Here are some of the evidences to support the existence of Pangea;

1. Using fossil evidences: Mesosaurus, a reptile animal that lived during the Permian, was found in both South America and Southern Africa. Since this animal could not swim nor fly, only a jointed landmass could have made them present in both continents.
2. Similar rock lithologies at the edges of continents: rock formations at the Western edge of Africa and South - Eastern part of Brazil matches with one another and have been believed to be once joined together.
3. Climatic clues such as glacial tills that are confined to temperate and polar regions have been found in tropical regions.
4. Wegener fitted the present day continent into a giant supercontinent and this provided a visual support for his claim.
5. Evidences from sea floor spreading revealing magnetic reversals at divergent margins suggests the prevalence of plate tectonics i.e moving plates on earth.

This among many other evidences underscores the existence of a supercontinent called Pangea.