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Reproductive cells are haploid (have 1/2 the chromosomes), whereas somatic/body cells are diploid (have the full set of chromosomes)
This makes sense if you think about it. Using the example from the question, every dog has 78 chromosomes. This includes two of each (there are two chromosome 1's, two chromosome 2's, etc. This is visible in the karyotype attached). One set of these chromosomes were inherited from the mother, and one set from the father. Each parent contributed 39 chromosomes (one chromosome 1, one chromosome 2, etc.). If the dog in the question were to have 78 chromosomes in its sperm cells, it would contribute two sets to its offspring. When combined with the chromosomes in the egg cell, the offspring would end up with extra chromosomes. Therefore, both the sperm and the egg cells will have 39 chromosomes, one of each. When combined, they will produce offspring with 78 chromosomes, the proper number.
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RNA polymerase binds to regions of DNA called promoters, which are "start" signals for transcription
Answer:
In uranium-lead dating, for instance, the radioactive decay of uranium into lead proceeds at a reliable rate. Based on the very old zircon rock from Australia we know that the Earth is at least 4.374 billion years old.
And that's how after rounding we know that earth is 4.5 years old.
Answer:
Calcification, or mineralization, then occurs when hydroxyapatite crystals deposit in the bone matrix.
Explanation:
Calcification -
It is the situation of the accumulation of the salts of calcium in the tissues of the body , is known as Calcification .
This process usually occurs during the bone formation , but in abnormal condition the soft tissues of the body gets harden , leading to the situation of Calcification , it is also known as mineralization .
The crystal deposited are of hydroxyapatite in the bone matrix .