Answer:
Common to all plant species, the cell wall is the tough outer coat that protects the plant cell. The cell wall is mostly carbohydrate‐based, comprising three major classes of polysaccharides: cellulose, hemicellulose and pectin. There are also important structural proteins as well as phenolic and aliphatic polymers.
Explanation:
Answer: The immune system
Explanation:
The immune system is a complex network of proteins and cells that defends the body against infection or any invasion. The human defense system in the body is actually made up of entire organs and vessel systems like the lymph vessels. The immune system is made up of organs that control the production and maturation of certain defense cells.
Initially, all living things are subjected to attack from disease causing agents. Even bacteria, so small that more than a million could fit on the head of a pin, have systems to defend against infection by viruses. This kind of protection gets more sophisticated as organisms become more complex.
Despite these similarities, prokaryotes and eukaryotes differ in a number of important ways. A prokaryote is a simple, single-celled organism that lacks a nucleus and membrane-bound organelles.
Answer:
E
Explanation:
A mutation that confers phenotypic benefits to individuals or a group of individuals would be considered a beneficial mutation.
<em>Mutation involves a sudden change to the gene coding sequence of the DNA. It can occur as a result of substitution, duplication, deletion, inversion, insertion, etc of purine or pyrimidine bases of the DNA.</em>
<u>These changes can be harmful, beneficial, or neutral to individuals. Those that have neutral effects in individuals are also called silent mutations.</u>
In the case of a duplication causing trichomatic vision in humans, it represents a form of beneficial mutation because it enables humans to be able to distinguish between red, green, and blue colors. The ability to distinguish among these colors improves the quality of life of humans.
What is the likelihood of their child having the disease is:
A. 0%
Explanation:
- The mother is heterozygous, thus she has an allele which is recessive and the other allele which is dominant.
- The father has no recessive allele for the gene.
- During meiosis in mother , two types of gametes will be produced. One type of gamete will have the recessive allele and the other type of gametes will have dominant allele.
- During meiosis in father, only one type of gametes will be formed which will have the dominant allele only.
- In a situation a female gamete with recessive allele is fertilized by a male gamete with dominant allele. The resulting zygote will be heterozygous.The effect of the recessive allele will be masked by the dominant allele and the child will not have the disease.
- In a situation a female gamete with the dominant allele is fertilized by a male gamete with dominant allele then the resulting zygote will be homozygous for dominant allele and obvioiusly the individual will not have the disease.
- Thus, in this case we can conclude that there is 0% chance of child having the disease.
