stem cells and differentation Flashcards
Define a stem cell
undifferentiated and unspecialised cells
what are 3 things that stem cells need
growth
development
tissue repair
what is potency
a stem cells ability to differentiate into different cell types
what is a totipotent stem cell
can differentiate into any type of cell
give an example of a totipotent stem cell
fertilised egg
8 or 16 first few mitotic divisions
what is a pluripotent stem cell
form tissue types
give an example of a pluripotent stem cell
embryo
what is a multipotent stem cell
can form a range of cells within a certain type of tissue
give an example of a multipotent stem cell
bone marrow
How are embryonic stem cells made
Two zygotes fuse
undergo mitotic divisions
eventually form an embryo
How can stem cells differentiate into different types of cells
Different proportions of organelles
different shapes
genes cave switched on and off
Give 2 ways that eroythocytes are adapted to its function
large surface area (biconcave shape)
no nuclei (more haemoglobin can be transported)
What is a neutrophil
A type of white blood cells
Describe the formation of embryonic stem cells
Totipotent- early stage of embryo development
pluripotent- blastocyst has formed (mass group of cells)
Give 2 places you can find adult stem cells
Bone marrow
umbilical cord
What type of stem cell are adult stem cells
multipotent
where are plant stem cells found
meristem tissue (found at the tip of roots and shoots) in the vascular cambium
give 3 diseases stem cells can have the potential to treat
heart disease
alzhiemers
Parkinson’s disease
what is the average width of a eryothycytes
7.5 nanometers
give 2 ways neutrophils are adapted to their function
cytoplasm contains many lysosomes to break down pathogens
multi-loved nucleus to squeeze through tiny spaces to reach infection
give 2 ways in which sperm cells are adapted to their function
acrosome has digestive enzymes which penetrate the ovum and fertilise the egg
flagella and tail are used for movement towards the egg
what is the role of palisade cells
to absorb large amounts of light for photosynthesis
give 2 ways in which palisade cells are adapted to their function
many chloroplasts present
thin cell wall- short diffusion pathway for products and reactants of photosynthesis
give 2 ways in which root hair cells are adapted to their function
long extension (root hair) increase surface area
thin cellulose cell wall (short diffusion pathway)
give 1 way in which guard cells are adapted to their function
gas exchange- stomota on their surface
give 1 way in which squamous epithelium are adapted to their function
thin layer of squamous epithelium cells- fast diffusion rate
give 1 way in which ciliated epithelium are adapted to their function
cilia- moves substances such as mucus across the membrane
goblet cells- release mucus to trap any unwanted particles
give 2 ways in which cartilage are adapted to their function
elastic fibres- flexible
collagen- strength
give 2 ways in which muscle tissue is adapted to their function
myocytes- helps in contraction in muscles
lots of mitochondria- for energy for movement
give 2 ways in which epidermis is adapted to their function
waxy cuticle- waterproof (reduces water loss)
guard cells- opens and closes stomotas