Answer:
1) the genes and chromosomes do not double after each generations because parental sex cells are haploid and only contain one set of chromosomes. During fertilization the two cells fuse to form a diploid zygote with two copies of genes and chromosomes. For example a normal human has 46 chromosomes (2 copies of 23 chromosomes) during reproduction gametes which contain 23 chromosomes (haploid) fuse to form an offspring with the correct number of chromosomes ( 23 + 23 = 46).
2) offspring only receive one set of chromosomes from each parent so to maintain the chromosome number of humans. If this did not happen you would not be the same species.
Answer:
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I would have to say skin or hair
The presence of vertebral column or notochord at any stage of life in any organism is the characteristic of vertebrate.
Explanation:
An animal is vertebrate if it fulfils the following criteria:
Presence of vertebral column or notochord.
Presence of endoskeleton or backbone.
The spinal cord runs above the vertebral column.
Humans embryo has notochord which becomes a vertebral column.
The alimentary canals end in the anus.
Mouth is present ta the anterior side of the vertebrate.
Have legs, fins or wings for movement.
Presence of a nervous system and sensory organs.
Presence of skin, lungs or gills.
Presence of a circulatory system.
Vertebrates include fish, amphibians, reptiles, birds and mammals.
Answer:
They collect more information.
Explanation:
The heliocentric model has been modified with the help of telescopes and probes because telescopes and probes collect more accurate information about the solar system and planets. Due to information collected from these instruments, scientists are able to modify the heliocentric model more accurately. So we can conclude that with the help of telescopes and probes, the heliocentric model has been modified.