Biology-Cell division and stem cells Flashcards
To revise for biology test coming up on Cell division and stem cells.
How is DNA found in eukaryotic organisms
In long strands
Purpose
Gene
A code to build a specific protein
True or Fasle
Every cell of a multicelluar organsim must contain a full set of DNA,chromsones and genes
True
A code to build a specific protein
Purpose
Gene
How are new body cells produced
Through Mitosis
State
Cell life cycle
Interphase: The cell prepares for division. It is further divided into:
G1 phase (Gap 1): The cell grows and performs normal functions.
S phase (Synthesis): DNA replication occurs, doubling the genetic material.
G2 phase (Gap 2): The cell continues to grow and prepares for division by producing proteins and organelles.
Mitotic Phase (M phase): The cell undergoes division. This phase includes:
Mitosis: The nucleus divides, and chromosomes are evenly distributed into two daughter cells. Mitosis has four stages:
Prophase
Metaphase
Anaphase
Telophase
Cytokinesis: The cytoplasm divides, resulting in two genetically identical daughter cells.
Examples
Rapidly Dividing Cells
RDCs
Cells like those in the skin, hair follicles, or the lining of the gut
have short cycles because they need to regenerate quickly to replace damaged or old cells.
Examples
Slowly Dividing Cells
SDCs
Liver cells(slowest cells in the body)
sometimes months, to complete the cycle since they don’t need frequent replacement.
Examples
Non-Dividing Cells
NDCs
Some cells, like neurons in the brain or cardiac muscle cells
remain in a resting state called G0 phase. These cells rarely, if ever, divide after maturity.
List
Mitosis
- Prophase: The chromatin condenses into visible chromosomes, each consisting of two sister chromatids joined at a centromere. The nuclear envelope begins to break down, and the mitotic spindle (made of microtubules) forms.
- Metaphase: The chromosomes align along the cell’s equatorial plane, also known as the metaphase plate. The spindle fibers attach to the centromeres of the chromosomes, ensuring proper alignment.
- Anaphase: The sister chromatids are pulled apart as the spindle fibers shorten. Each chromatid, now an individual chromosome, moves toward opposite poles of the cell.
- Telophase: The chromosomes reach the poles, and a new nuclear envelope forms around each set, creating two nuclei. The chromosomes begin to decondense back into chromatin.
Define
Zygote
A zygote is a fertilized egg
Define
Embryo
Ball of stem cells in uterus after fertiliasation
True or Fasle
Plants do not possess stem cell
Fasle
Location
Plant stem cells
Meristem regions such as the shoots,roots and the stem
List
Methods of plant cloning
- Cuttings: A simple and widely used method. A part of the plant, like a stem, leaf, or root, is cut and placed in soil or water to grow roots and develop into a new plant.
- Layering: In this method, a branch or stem is bent to the ground and covered with soil while still attached to the parent plant. Once it develops roots, it can be separated to grow as an independent plant.
- Grafting: A part of one plant (the scion) is attached to another plant (the rootstock). This is often used for fruit trees and roses to combine desirable traits like disease resistance or better yield.
- Micropropagation: A high-tech laboratory method where plant cells or tissues are cultured in a nutrient medium under sterile conditions to grow new plants. It’s great for mass-producing plants.
- Bulbs and Tubers: Some plants, like potatoes or tulips, naturally produce bulbs or tubers that can be separated and replanted to grow clones.
Why are pan
- The main reason to clone plants is to mass produce organisms with desired qualities
- They aslo can be sold for a hhigh commericial value
