LAMARCK's THEORY
Jean Baptiste Lamarck (1744-1829) proposed a theory which was published in "<em>Philosophie Zoologique"</em> (1809). This theory is simply known as Lamarckism. It has two main postulates:
1. Use and disuse of organs
2. Inheritance of acquired characters.
Example
He explained his theory by giving the examples:
1. Neck length of Girrafes
2. Webbed toes of water birds, and
3. Wings of penguins
Explanation
Lamarck explained that water birds use toe for swimming, with the passage of time webbed were developed in their toes. these features were then transferred to their offspring.
Drawback
Lamarck theory was based on natural observation. It did not explain the genetic basis of such characteristics.
Answer: Oogenesis
Explanation:
Oogenesis is a process in female reproductive system in which a matured ovum is formed from egg cell.
In human reproductive system one mature ovum is produced from four haploid cells during meiosis. This ovum is very large and it unite with the sperm to produce zygote.
There are three stages of Oogenesis, the multiplication phase,the growth phase and maturation phase.
In the multiplication phase, the germinal cells divide to form oogonia. The oogonia multiply and form oocytes. The oocytes pass through the growth phase and mature to form ovum.
Chlorophyll is a pigment found in the thylakoid membranes of the chloroplasts in the leaves. This is why plants are green. The simple answer is that plants are green because they have green chloroplasts.
Answer:
mice and humans share virtually the same set of genes
Explanation:
Almost every gene found in one species so far has been found in a closely related form in the other. Of the approximately 4,000 genes that have been studied, less than 10 are found in one species but not in the other.
