Spindle fibers play a vital role in ensuring the proper distribution of chromosomes to daughter cells during cell division, specifically in the process of mitosis and meiosis. These fibers are part of the cellular structure known as the mitotic spindle, which is responsible for separating the duplicated chromosomes and ensuring their accurate allocation to each daughter cell.
The formation of spindle fibers begins during the early stages of cell division when the centrosomes, also known as microtubule organizing centers, duplicate and migrate to opposite poles of the cell. As the cell progresses through mitosis or meiosis, the spindle fibers extend outward from the centrosomes and attach to the chromosomes.
The spindle fibers consist primarily of microtubules, which are dynamic protein polymers. There are two types of spindle fibers: kinetochore fibers and polar fibers. Kinetochore fibers originate from the centrosomes and connect to the specialized protein structures called kinetochores that assemble at the centromere region of each duplicated chromosome. These fibers exert tension on the chromosomes, aligning them at the cell's equatorial plane during metaphase.
During anaphase, the kinetochore fibers begin to shorten, pulling the sister chromatids apart. The shortening of the kinetochore fibers is powered by the depolymerization of microtubules at their kinetochore ends. As a result, each chromatid is directed towards the opposite poles of the cell.
Simultaneously, polar fibers, also known as interpolar microtubules, extend from one pole of the cell to the other. These fibers overlap in the cell's center and assist in separating the poles further apart, helping to elongate the cell during anaphase.
Overall, the combined action of kinetochore fibers and polar fibers ensures the accurate distribution of chromosomes to the daughter cells. The spindle fibers undergo a highly orchestrated process of assembly, attachment, tension generation, and depolymerization, all of which contribute to the successful partitioning of the genetic material during cell division.
O2) Layer A - Layer D - Layer B - Layer C
O 3) Layer D - Layer C - Layer B - Layer A
4) Layer D - Layer A - Layer C - Layer B
Answer:
D-C-B-A
Explanation:
Oldest crust on the bottom
(B) ribosomes
(C) mitochondria
(D) chromosomes
When compared to a cheek cell, a muscle cell contains more ribosomes and mitochondria (Option B and Option C).
In conclusion, when compared to a cheek cell, a muscle cell contains more ribosomes and mitochondria (Option B and Option C are correct).
Learn more in:
Muscle cells contain more mitochondria compared to cheek cells.
When compared to a cheek cell, a muscle cell generally contains more mitochondria (option C). The reason for this difference lies in the cells' respective functions. A muscle cell requires a larger amount of energy to contract and exert force, and mitochondria are the organelles that produce ATP, the cell's primary energy source. Consequently, muscle cells need a high concentration of mitochondria to meet their energy demands.
Contrastingly, cheek cells (epithelial cells) primarily serve to protect and seal off the body, and to absorb and secrete substances. They don't have as heavy energy demands as muscle cells do, and therefore generally have fewer mitochondria. Both cell types have similar numbers of vacuoles, ribosomes, and chromosomes as they are essential to general cellular processes and not specific to cell types.
#SPJ11
Answer:
metamorphic
Explanation:
Answer:
Bone is a solid tissue, which resists a high impact of forces in its major axis.
The function of this fabric is not to transmit sounds, since it does not provide the elasticity, and the necessary elongation that is needed to generate the rope effect as in the case of muzzle cords.
Explanation:
The more rigid and less elastic the fabric is, the less sound it will transmit.
Sound strings, or mouth strings, are those that tighten, are flexible and resonate with different vibrations, in the case of bone tissue, sound vibrations are not influenced in their conformation because they do not have the ability to transmit them. .
The bone tissue, transmits impact forces or high newton levels, does not fulfill the function of transmitting vibrations and emitting sounds in terms of this type of vibrations and their frequencies.
They eat the rocks
They create new bacteria that breaks away rocks
They secrete acid that breaks away rocks
They eat the acid in rocks
Answer:
The correct answer is - They secrete acid that breaks away rocks
Explanation:
Lichen causes chemical weathering to break the rocks quickly which is the excretion of various acids like oxalic acid and many more organic acids that can cause a significant impact on the rock by dissolving minerals.
By breaking the rocks it forms the ground for the plant that will come later in place of the bare rocks by this chemical weathering process. An example of chemical weather is a change of the granite to clay with the help of hydrolysis.