Dinosaur fossils had been known for centuries as "dragon bones" or the remains of giants, but it wasn't until Dean William Buckland of Oxford, England described the carnivorous "lizard" Megalosaurus<span> (in 1824) that they were formally studied as an extinct group of giant reptiles</span>
Answer:
A
Explanation:
Earth's orbit is not constant because it does not travel in a circle but more of an ellipses.
I may be wrong but I think it’s the second one. They speed up reactions, and there’s a certain enzyme for a certain reaction.
Answer:
Both have two circuits for circulation.
Explanation:
- The two circuits of circulations are known as the systemic circuit and the pulmonary circuit.
- In the<u> systemic circuit</u> oxygenated blood from the heart is pumped to all parts of the body through the blood vessels and then the blood is pumped back to he heart.
- In the<u> pulmonary circuit</u> deoxygenated blood from all parts of the body is pumped from the heart to the lungs to be oxygenated and after it is oxygenated it is pumped back to the heart.
Answer:
47
Explanation:
We all know that gametes like egg cell and sperm have haploid set of chromosomes but here as per this question she has produced 2 copies of chromosome 21. For the sake of maintaining haploidy, she was supposed to have only a single copy of chromosome 21 as a result of which her egg cell was supposed to have 23 chromosomes not 24.
But, this is a case of non dis-junction. Also, in a normal sperm there are no such copies of any chromosome i.e. there is a haploid set of chromosomes. It means that sperm must be having only 23 chromosomes. So we can easily infer that when the egg cell and sperm will fuse, the zygote will have 47 chromosomes (24 from egg cell and 23 from sperm).
