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).
Answer:
b. giving birth to live young (viviparous)
Explanation:
Monotremes include duck-billed platypus and few other mammalian species that are oviparous. These mammalian species do not give birth to young ones, that is, they are not viviparous. Rather they lay eggs and are oviparous.
These species are also characterized by the absence of teeth. The primitive monotremes also exhibit external fertilization.
Examples of egg-laying mammals include anteaters or echidnas and the duck-billed platypus. The laid eggs are carried by females in an abdominal ouch to keep them warm.
Well those that are in that ecostems could died from no water or the could walk on it and it breaks
