Answer:
The correct option is option b that is<em> Homo erectus</em> is the common ancestor of<em> Homo neanderthalensis</em> and<em> Homo sapiens.</em>
Explanation:
<em>Homo erectus </em>appears about 2 mya, possibly during the Pleistocene epoch and are considered as direct ancestor of human.They are called as upright man as they use legs for walking without any support.They are thought to be capable of doing certain things like hunting, starting fire,art making, create speech etc.
<em>Homo neanderthal</em> was the most recent ancestor species of modern human as they appear about 40,000 years ago.
They became extinct as they did't fight against environmental hazards and the major cause of their extinction that scientists have claimed that they did't adapt the modern techniques that the modern human does.
Answer:
Explanation:
The central nervous system (CNS) does not have capacity to repair itself but, the PNS or the peripheral nervous system can repair and regenerate itself. The PNS can regenerate its damaged axon only when its cell body or cyton and its neurilemma are intact. The proximal end of the cyton has growth cones. The axon grows from the cones.
Answer:
Basal meristems
Explanation:
Meristems are the portion of plants able to generate any kind of new tissues. Therefore, the way plants keep their meristems protected is related to climate adaptation.
Grasslands tend to be arid ecosystems, so grasses have developed basal meristems, meaning they spend the dry season very close or under soil, where water evaporates slowlier than above surface, until wet season allows meristems to generate new stems and leaves.
This disposition is also useful in cases of fire and grazing, which are also frecuent in grasslands.
Answer:
Depending on changes, that occur with DNA, all types of DNA mutations can be divided into two main groups:
gene mutation;
chromosomal mutation.
Explanation:
When a cell undergoes meiosis,the outcome of the process is FOUR HAPLOID CELLS.
Meiosis refers to a form of cell division which always results in the formation of four daughter cells. The four daughters cells produce have diploid cells which contains half the original of chromosomes from the parents. A diploid cell has two of each chromosome, one from each parent. The eggs and the sperms that are involved in reproduction possess haploid cells. In meiosis, the whole process start with diploid cells which divide twice to produce four haploid cells.
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