Answer:
1. Chromatin condense into chromosomes.
4. Homologous chromosomes pair up (formation of tetrads).
5. Homologous chromosomes separate and move to poles.
2. Sister chromatids separate.
3. Chromosomes unravel in to chromatin.
Explanation:
This question portrays the process of meiosis in a cell. The ordered sequence of events in the options are:
1. Chromatin condense into chromosomes - This process occurs in the Prophase stage. Prior to the cell division, the nuclear material is found as Chromatin material. This Chromatin material then undergoes condensation to form visible chromosomes.
4. Homologous chromosomes pair up (formation of tetrads) - This process also occurs during the Prophase stage of meiosis I. In this stage, homologous chromosomes (similar but non-identical chromosomes received from each parent) are paired up side by side to form a structure known as TETRAD or BIVALENT.
5. Homologous chromosomes separate and move to poles - This process characterizes the Anaphase stage of meiosis I. Homologous chromosomes are pulled apart to opposite poles of the cell by spindle microtubules.
2. Sister chromatids separate - After meiosis I, meiosis II involving sister chromatids instead of homologous chromosomes follows. In the Anaphase stage of meiosis II specifically, sister chromatids are pulled apart towards opposite poles of the cell.
3. Chromosomes unravel in to chromatin - After the whole division process i.e. karyokinesis (division of the nuclear material), the chromosomes begin to unravel to form the CHROMATIN threads once again. This process occurs in the Telophase stage of meiosis.
Answer/Explanation:
In humans, we breathe in oxygen via the respiratory system. The oxygen enters the lungs. The air sacs in the lungs - the alveoli - are the site of gas exchange in the lungs and are where the circulatory and respiratory systems interact.
The alveoli take in the oxygen, where it diffuses into the capillaries (circulatory system). Blood, which passes through the capillaries takes this oxygen to all the cells in the body. Oxygen binds to haemoglobin in red blood cells, which transport it around the body.
Additionally, blood also transports carbon dioxide back to the alveoli of the lungs, where it diffuses into the lungs and is expelled when we breathe out
Answer:
Spirogyra is a genus of green algae that belong to the order Zygnematales. These free-flowing, filamentous algae are characterized by ribbon-shaped chloroplasts that are arranged in a helical manner inside the cells. So the name is derived from the spiral arrangement of chloroplasts in these algae.
Explanation:
Answer:
Microtubules composed of tubulin protein.
Explanation:
The cytoskeleton is composed of three well defined filamentous structures: microtubules, microfilaments, and intermediate filaments. Each of these filamentous structures is a polymer of proteinic subunits united by weak, not covalent connections.
Microtubules are long hollo cylindric tubes with no ramifications of a diametre near to 25 nanometers. They are constituted by two subunits of tubulin protein which polymerize to form microtubules. These filaments shape the cell and are involved in intracellular transport. Microtubules extend from an organizing center near the nucleus to the cellular surface.
