1.Biological species concept
2.Cladistic species concept
3.Cohesion species concept
4.Competition species concept
5.Ecological species concept
6.Evolutionary species concept
7.Isolation species concept
8.Phenetic species concept
9.Phylogenetic species concept
10.Recognition species concept
11.Typological species concept
For descriptions just look them up :)
Answer:
Electron microscope is a device which is used to see microscopic objects using electon. In this tyoe of microscope electron is thrown on an object whose image is formed on the screen. It resolution power is 10,000X. If the internal structure of an object is to be observed then SEM is used, however for three dimensional structure, TEM is used.
Answer:
An atom is composed of two regions: the nucleus, which is in the center of the atom and contains protons and neutrons, and the outer region of the atom, which holds its electrons in orbit around the nucleus.
Explanation:
Answer:
when a concentration gradient exists and more of the substance is on the inside of the cell
Explanation:
Active transport moves substances against the concentration gradient, from an area of low concentration to an area of high concentration. It requires the use of energy, usually in the form of ATP.
Hope that helps.
Answer:
The correct answer is option C, that is, in the mother in meiosis II.
Explanation:
A nondisjunction in meiosis I produce all the aneuploid gametes, while nondisjunction at meiosis II produces 50 percent aneuploid gametes and the 50 percent normal gametes comprising haploid number of chromosomes.
As it is mentioned that one of the brothers possess normal number of chromosomes (46), the mother encounters nondisjunction at meiosis II resulting in the formation of one n+1 gamete exhibiting two copies of X chromosome. Fertilization of this n+1 gamete with sperm results in the creation of zygote (47, XXY).
