concise verbal or mathematical statement of a relation that expresses a fundamental principle of science, like Newton's law of universal gravitation.
Seed coat-ovary wall association is not correct.
The seed coat originates from the maternal tissue, that is, the integuments. It is one of the three components of a plant seed, in supplementation to the embryo and the endosperm. The aim of the seed coat is to safeguard the seed from temperature-related, physical or water destruction. It is a protective outer covering of the seed.
On the other hand, the ovary wall refers to the wall of the ovary of a flower that ultimately develops into a pericarp or fruit wall.
Answer:
The options are missing, the options are;
I. an error in anaphase I
II. an error in anaphase II
III. an error of the first postfertilization mitosis
IV. an error in pairing
A) I or II only
B) II or IV only
C) III or IV only
D) I, II, or III only
E) I, II, III, or IV
The correct answer is A
Explanation:
Meiosis is the type of cell division undergone by reproductive cells to produce gametes that have a reduced number of chromosomes. Normally, a diploid (2n) organism like humans undergo meiosis to produce haploid gametes (n). This reduction occurs because homologous chromosomes (similar but non-identical chromosomes received from both parent) and sister chromatids are separated during the anaphase of meiosis I and II respectively. Hence each cell (gamete) at the end of meiosis now possess 23 chromosomes each as opposed to the 46 in the producing organisms.
However, an anomaly called ANEUPLOIDY can occur in which one or more chromosomes fail to separate during anaphase. This failure to separate is referred to as NON-DISJUNCTION and it results in gametes that have extra chromosomes i.e. n+1 or missing chromosomes i.e. n-1.
Note that, this error can occur in either meiosis I or II depending on whether it is homologous chromosomes or sister chromatids that fail to separate.
According to the question, a gamete with missing chromosome (n-1) is described, hence, it will undergoes fertilization to produce a zygote with 2n-1 chromosomes i.e. A diploid organism missing one chromosome (46-1) = 45 chromosomes. This particular condition is referred to as MONOSOMY.
Answer:
There is a very well developed mechanism is transportation of the materials from the one part of the cell body to another as we can expect some of the proteins and lipids inside the membrane of the molecules.
- There is a very well developed model for the transported of the molecules across the cell membrane in a proper way. As there are is two ways or nature of materials transportation inside the cell's membrane, and inside both the mechanisms the proteins are greatly involved in them, as the two mechanisms are:
- Active transport of materials across the membrane,
- Passive transport of the materials.
- However, it is been confirmed after research that there is minimum amount of energy required to carry out the whole process of trans-portion of the materials and its only made possible through the protein channels inside the cell membrane's structure along with having the lipid bi-layer.
- However, it is more obvious that these materials move across the cell membrane body due to the possible difference in there potential.
- There are are also a number of molecules of the carbohydrates which make it possible for the whole process of material transportation across the membrane more easy.
