Answer:
The correct answer will be option-D
Explanation:
The Hardy-Weinberg principle was given by two different scientists Godfrey Hardy and the Wilhelm Weinberg which worked on understanding the population genetics.
The Hardy- Weinberg equilibrium is based on certain assumptions like population should have no mutations, no emigration, no selective pressure, no migration and the population should be infinite.
Since the Hardy- Weinberg equilibrium is widely used to determine the allelic frequency from the genotype therefore option-D is the correct answer.
Answer:
We have just seen that pathogens constitute a diverse set of agents. There are correspondingly diverse ranges of mechanisms by which pathogens cause disease. But the survival and success of all pathogens require that they colonize the host, reach an appropriate niche, avoid host defenses, replicate, and exit the infected host to spread to an uninfected one. In this section, we examine the common strategies that are used by many pathogens to accomplish these tasks.
Explanation:
The first step in infection is for the pathogen to colonize the host. Most parts of the human body are well-protected from the environment by a thick and fairly tough covering of skin. The protective boundaries in some other human tissues (eyes, nasal passages and respiratory tract, mouth and digestive tract, urinary tract, and female genital tract) are less robust. For example, in the lungs and small intestine where oxygen and nutrients, respectively, are absorbed from the environment, the barrier is just a single monolayer of epithelial cells.
Skin and many other barrier epithelial surfaces are usually densely populated by normal flora. Some bacterial and fungal pathogens also colonize these surfaces and attempt to outcompete the normal flora, but most of them (as well as all viruses) avoid such competition by crossing these barriers to gain access to unoccupied niches within the host.
Answer:
A. increased
Explanation:
In general, life has gotten more complex through history. However, there have been times when biodiversity as been substantially reduced. (We may be in one of those times at present.) We cannot say that the complexity of life has increased <em>throughout</em> the history of any particular place, but we can say the long term trend has been one of increase.
Since between the two alleles (B for black and b for white) there is an incomplete dominance this means that the homozygotes for the one dominant trait (BB genotype) will be black, the homozygotes for the other trait (bb) will be white, and the heterozygotes (Bb) would be intermediate- grey.
So, the two grey lizards have the Bb genotypes.
When they cross we will get Bb x Bb
1 : BB ( black lizards)
2: Bb ( grey lizards)
1: bb ( white lizards)
