Environmental factors do influence natural selection because they can increase or decrease the population of a species, by selecting those with only favorable traits.
Answer:
the petrified log looks like the original tree.
Explanation:
A tree to be petrified first needs to be buried. An element laying on the surface can not be petrified because it is exposed to many different factors (such as<em> organisms, microorganisms, climatic conditions</em>, etc.), that affect the petrification process. So, in the case of a fallen tree, first, it needs to be covered by many sedimentary layers. Once it is underground, it also needs the presence of underground water and minerals. Water replaces the original organic material with minerals (silica, calcite, and pyrite). This replacement process results in the conversion of the woody material into a fossil of the original material. Very often, the tree details are so preserved that the fossil looks exactly like the original trunk.
Depending on the preservation degree, a fossil can be useful for different studies about the past.
Answer:
Mark pathogenic cells for destruction. (Ans. B)
Explanation:
Antibodies are generated by the plasma cells, and once these secreted, they attach quickly to the surface of the toxin and stop the toxin from infecting the normal body cell by blocking key extracellular sites.
Antibodies also help to mark pathogens for destruction by the help of macrophages or neutrophils and they are known as phagocytic cells because they are highly excited to macro-molecules complexed with antibodies.
Answer:
The most likely preferable option will be - A.
A. Insects.
Explanation:
The basic features of insects -
- Insects have an exoskeleton outside of their body or a shell-like covering on the outside of its body.
- Insects have a body with three segments: head, thorax, and abdomen.
- Insects have two large eyes and a pair of antennae on top of their heads.
- Insects have six legs (3 pairs).
- Insects have two pairs of wings on the dorsal part of their body.
Answer:
8 chromosomes in each daughter cell
Explanation:
Mitosis creates identical cells. If there are 8 chromosomes in the parent cell, there will be 8 chromosomes in each daughter cell. The way it works is that in late Interphase, the number of chromosomes and DNA double. In this case there would be 16 chromosomes. And when the cell splits into two during cytokinesis, each of the two would get half the chromosomes. Hence, there would be 8 chromosomes in each daughter cell.
