FreeNotes
In animal cells, cytokinesis occurs through a process called cleavage, where the cell membrane pinches inward at the center. In plant cells, cytokinesis involves the formation of a cell plate that eventually becomes the new cell wall, separating the two daughter cells. Related Questions: Give the modifications of epidermal cells for: Explain the spindle in … Read more
In rapidly dividing cells, the G1 phase is often reduced or shortened. This allows the cell to spend less time in growth and more time in DNA replication and division, enabling faster cell proliferation. Related Questions: Give the modifications of epidermal cells for: Explain the spindle in detail. What is crossing over? Explain the … Read more
Feature Meiosis I Meiosis II Definition First division of meiosis, reducing chromosome number Second division of meiosis, separating sister chromatids Type of Division Reductional division (diploid → haploid) Equational division (haploid → haploid) Homologous Chromosomes Homologous chromosomes pair up and separate Homologous chromosomes do NOT pair up Crossing Over Occurs during prophase I (genetic recombination) … Read more
Epithelial cells of the skin divide continuously to replace the cells lost from the outer layer due to wear and tear. Skin cells undergo regular division to maintain the integrity and function of the skin barrier, and to repair any damage caused by environmental factors. Related Questions: Give the modifications of epidermal cells for: … Read more
Cell A, which continues in the cell cycle, will synthesize materials required for growth and DNA replication during the G1 and S phases, respectively. Cell B, which exits the cycle, will not proceed with these processes, as it has entered the G0 phase or stopped dividing. Therefore, the materials synthesized by cell A will support … Read more
The G0 phase is a resting phase where the cell exits the normal cycle and stops dividing. Cells in the G0 phase are metabolically active but do not undergo mitosis. Some cells remain in G0 for an extended period, such as neurons, while others may re-enter the cycle when needed. Related Questions: Give the modifications … Read more
Crossing over is the process where homologous chromosomes exchange genetic material during prophase I of meiosis. This exchange leads to genetic recombination, resulting in offspring with a mixture of genetic traits from both parents. This process enhances genetic diversity. Related Questions: Give the modifications of epidermal cells for: Explain the spindle in detail. Which organelles … Read more
The spindle is a structure made of microtubules that forms during cell division. It helps in the movement of chromosomes. The spindle fibers extend from the centrosomes and attach to the centromeres of chromosomes. The role of the spindle is to ensure that the chromosomes are aligned properly during metaphase and are then separated into … Read more
a. Exchange of gases – Stomata in the epidermis of leaves allow gas exchange. Guard cells regulate the opening and closing of stomata. b. Absorption of water and minerals – Root hair cells have elongated structures to increase surface area for better absorption of water and minerals from the soil. Related Questions: The science of … Read more