What is still lacking in the hypothesis of an asteroid impact as the cause of the end-cretaceous mass extinction?
1 answer:
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Answer:The image to this question is attached.
Answer is the ovary
Explanation: the process by which egg is produced is called oogenesis. It involves the mitotic division of the primodial germ cells to from a oogonia. The oogonia becomes enveloped by follicle cells . Oogonia grows to become the primary oocyte. Each primary oocyte is diploid. It then undergoes the first meiotic division to form the secondary oogonia and a smaller polar nody. all this process of development occurs in the ovary.
After it is released from the ovary, fertilization occurs and it undergoes the second meiotic division to from a polar body and an ovum.
The primary oocyte however remains in prophase of meiosis l throughout childhood.
Answer:
The third and the fourth option.
Explanation:
The number of products and reactants are balanced
Chromosomes are composed of deoxyribonucleic acid (DNA) mole
There are mainly two molecules that function as genetic material in living organisms.
These are ribonucleic acid(RNA) and deoxyribonucleic acid(DNA).
The organisms having DNA as genetic material require packaging of DNA as it is a long polymer of deoxyribonucleotides.
In the case of human beings, the length of DNA in a cell is approximately 2.2 meters which is very large as compared to the size of the nucleus( approximately 10^-6 meters).
So, the DNA has to be made compact for it to be present inside the nucleus of a cell.
Therefore, the DNA present inside the nucleus of a cell undergoes coiling and compaction through several stages before finally becoming a chromosome, which is shown in the adjoining diagram.
Thus, chromosomes are composed of deoxyribonucleic acid (DNA) molecules.
To know more about "DNA Packaging", refer to the following link:
brainly.com/question/14702559?referrer=searchResults
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