Answer:
In the case of the algae, each individual cell is responsible for absorbing its own water. This makes the algae nonvascular compared to the highly vascular plant species. In this connection, algae also lack several key structures that are normally present in ordinary plants like the leaves, roots and stem.
I think this stage is the cytokinesis. It is <span>the division of the cytoplasm to form two new cells, overlaps with the final stages of mitosis. It may start in either anaphase or telophase, depending on the cell, and finishes shortly after telophase. Hope this helped.</span>
Answer:
Did alleles for drug resistance occur in bacterial populations that afflict humans, prior to the widespread use of antibiotics in medicine and agriculture? a. No—mutations for drug resistance occur in response to antibiotic use. ... Yes—alleles for resistance arise due to random mutation, so are always present.
Explanation:
Genetic fingerprinting – the analysis of DNA in order to identify the individual from which the DNA was taken to establish the genetic relatedness of individuals. It is now commonly used in forensic science (for example to identify someone from a blood sample) and to determine whether individuals of endangered species in captivity have been bred or captured from the wild.
<span>•DNA sequencing – the determination of the precise sequence of nucleotides in a sample of DNA or even a whole genome e.g. the Human Genome Project. </span>
<span>The process of electrophoresis: </span>
<span>DNA is chopped, close to the VNTR regions, into fragments using restriction enzymes. The DNA fragments are placed on the agarose gel and a direct current is applied continuously to the gel. The DNA fragments are attracted to the anode. The shorter the fragment, the faster it moves. </span>
<span>The fragments are transferred onto an absorbent paper placed on top of the gel. The paper is heated to separate the 2 strands in each DNA molecule. Complementary probes which have a radioactive phosphorus isotope are and this pair up with the DNA strands. The paper is placed on an X-ray film and the film goes dark due to radiation emitted by the probes. Now we end up with a pattern of dark stripes on the film matching the positions reached by the fragments in the agarose gel.</span>
Question 1 The world's population is spread very unevenly. Some spaces are empty or very sparsely populated: we speak of human deserts:
• Cold polar environments are the least populated regions: the ground, frozen permanently, prevents any form of agriculture, the very low temperatures make the habitat difficult.
• The hot or cold desert environments are also not busy: the lack of rain and the strong heat during the day limit the activities of men. The only exceptions are oases.
• The role of relief is more difficult to define. High temperate mountains like the Alps are generally sparsely populated but tropical chains like the Andes have a high population density. However, men have generally settled in the plains, in the valleys (along with the rivers) and on the coasts.
There are also other factors unrelated to land factors that influence population density such as job availability, or even historical factors.
Question 2: Birth rate:
The birth rate (sometimes called the crude birth rate) is the ratio of the annual number of births to the average total population for that year. When the population grows, the contact between people will be more permanent, and it will increase the marriage rate, and thus the birth rate. Age structure:The age structure is a mode of graphical representation of the structure (of age as well as of sex) of a population which constitutes a synthetic image of the past, present and future of the population.When a population resides for a long time in the same place (in favorable conditions, not raising the death rate and without moving), this will vary the age structure by observing an increase in the elderly population.
