Speciation in a deer population as a result of geographic isolation
Answer:
C. A primary sex cell in a human forms a gamete that contains 24
chromosomes.
Explanation:
The gametes are the cells that form offspring.
Answers:
- The sequence encodes a gene that is critical for life and cannot be easily mutated while retaining function.
- The sequence is contained in a retrovirus that has infected both species.
1- Explanation:
6.8 million years is a considerable period of time and if the cats were evolved in two different specie then technically they should have substantially different sequences of gene. However, there are some genes that are critical for the survival of the organisms because they encode a function which is equally important for the organisms of a certain category, even if they are different specie.
For example, the essential genes that are involved in maintenance of metabolism, initiation of replication or translation of genes. Therefore, with the period of time, the mutation of even a single nucleotide can be lethal for these genes, and if it happens organism will simply die. So, if one organisms is died that cannot take part in the process of evolution and would clearly be cut off from the process, However, those who survive can undergo some other mutations and become separate specie.
2- Explanation:
A retro virus inserts itself in to the genome of host organisms and become a part of them. It is very difficult to detect the presence of the retro virus until the organism undergoes infection due to its attack. Cats are a favorable host for retroviruses - called lentiviruses which attack the cats to cause a critical syndrome Feline Immunodeficiency Virus or FIV. Therefore, it is possible that same retrovirus having a particular sequence has attacked both cats and the sequences were taken from those cats.
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Answer:
In our respiratory system, there is a pair of external nostril situated above the upper lip that receives atmospheric air and passed to the pharynx (a common passage for air and food). The pharynx passed this air to the trachea via larynx (known as the soundbox). The trachea is an extended part which is divided into left and right primary bronchi. Bronchi divide into secondary bronchi, tertiary bronchi, and bronchioles that ending up in thin terminal bronchioles. Each terminal bronchiole constitutes a number of irregular-walled, thin and vascularised bag-like structures called alveoli which are the primary sites of gases exchange.
This is created from splitting atoms
