6 Cell Division/ cellular organisation Flashcards
What is a gene
A gene is a section of DNA
what are histone proteins
A histone is a protein that provides structural support for a chromosome. Each chromosome contains a long molecule of DNA, which must fit into the cell nucleus. To do that, the DNA wraps around complexes of histone proteins, giving the chromosome a more compact shape.
what are chromosomes
a threadlike structure of nucleic acids and protein found in the nucleus , makes up genes
what are chromatids
each of the two threadlike strands into which a chromosome divides longitudinally during cell division.
what is a centromere
the region of a chromosome to which the microtubules of the spindle attach, that holds together the two chromatids
what is a centriole
Centrioles are paired barrel-shaped organelles located in the cytoplasm of animal cells near the nuclear envelope. Centrioles play a role in organizing microtubules that serve as the cell’s skeletal system. They help determine the locations of the nucleus and other organelles within the cell.
what’s the main difference between meiosis and mitosis
In mitosis there are 2 identical cells produced
In meiosis there are 4 semi identical cells produced
how many daughter cells are produced in mitosis
2
how many daughter cells are produced in meiosis
4
how many cell divisions are their per cycle in meiosis
2
how many cell divisions are their per cycle in mitosis
1
is their variation in meiosis
yes
is their variation in mitosis
no
what’s the order of events in mitosis (egg telophase ect )
interphase
prophase
metaphase
anaphase
telophase.
what happens in mitosis interphase
During interphase, the cell acquires nutrients, creates and uses proteins and other molecules, and starts the process of cell division by replicating the DNA.
what happens in mitosis prophase
separates the duplicated genetic material carried in the nucleus of a parent cell into two identical daughter cells. During prophase, the complex of DNA and proteins contained in the nucleus, known as chromatin, condenses.
what happens in mitosis metaphase
individual chromosomes are spread out in the cell nucleus. During metaphase, the nucleus dissolves and the cell’s chromosomes condense and move together, aligning in the centre of the cell through the use of spindle fibres.
what happens in mitosis anaphase
the sister chromatids separate from each other and are pulled towards opposite ends of the cell
what happens in mitosis telophase
membranes form around the two groups of chromosomes, each at opposite ends of the cell, to produce the two nuclei of the daughter cells. The spindle disappears, and the cytoplasm usually divides
at what stage to spindle fibres appear
prophase
at what stage to spindle fibres disappear
telophase
what’s a Red blood cell called
Erythrocyte
What’s a white blood cell called
Neutrophil
what is squamous epithelium (2)
-flattened epithelial cells
-used to line surfaces within the body, almost no friction
What is ciliated epithelium (3)
- columnar epithelium
- More trapped dust out of trachea
- Extension from cytoplasm (cilia)
what are the 3 types of cartilage + where they are located
Hyaline - nose, ends of long bones
Fibrous - vertebrae disks, in knee
Elastic - outer ear
Palisade cells (4)
- in mesophyll
- contain chloroplasts
- thin cell walls
- large vacuole (maintains turgor pressure)
Root hair cells (2)
-near the growing tips of roots
-extensions of root hairs (increase SA)
how do Guard cells work (4)
When guard cells lose water and become less swollen as a result of osmatic forces, they change shape and the stoma closes to prevent further water loss.
the cell wall of a guard cell is thicker on one side so the cell doesn’t change shape symmetrically as its volume changes.
they contain more mitochondria to produce ATP in order to let movement against the concentration gradient
Vacuole to take up water and become turgid
Why does overwatering kill plants (3)
-water floods soil, pushes oxygen out which is needed for respiration to produce ATP- minerals more scares
-ATP is needed to bring minerals in to attract water, as the water potential in the root hair cell is lowered, therefore no water brought in
- Plant collapsing (lack of water ), yellow leaves (lack of minerals)
What are stem cells
undifferentiated cells (unspecialised)
what is stem cell potancy
the higher the potency the more cells it can differentiate into
what are totipotent cells
cells which can differentiate into any type of cell
what are pluripotent cells
cells which can form all tissue types but not whole organisms
what are multipotent cells
These stem cells can form a range of cells within a certain type of tissue
What is the life span of a red blood cell
120 days
what are uses of stem cells (10)
heart disease
type 1 diabetes
Parkinson’s disease
Alzheimer’s disease
macular degeneration
birth defects
spinal injury’s
burn treatment
drug trials
development biology
