Answer:
Explanation:
Because they appeared quickly in geological time, and moulted like other arthropods, trilobites serve as excellent index fossils, enabling geologists to date the age of the rocks in which they are found. They were among the first fossils to attract widespread attention, and new species are being discovered every year.
Answer:
Explanation:everything looks good
Answer:
A) XX
Explanation:
Each human cell is diploid (2n) and possesses 23 pairs of chromosomes. Out of 23 pairs, 22 pairs are autosomes and 1 pair is sex chromosomes. Sex chromosomes are designated by alphabet X and Y. In human females, each cell has two XX chromosomes, whereas males have one X and one Y sex chromosome.