Stem Cells

Question 1

Characteristics of animal cells

Answer 1

• Eukaryotic
• Heterotrophic (consumes living things for energy and nutrients
• Part of multicellular organisms
• Can be part of muscular, nervous systems
• Has a nucleus, cell membrane, mitochondria, ribosomes, many small vacuoles, and DNA
• Reproduce sexually (two parents contribute genetic information to make a unique offspring)

Question 2

Characteristics of plant cells

Answer 2

• Multicellular organism
• Eukaryotic
• Autotrophic (make their own food)
• Make energy from photosynthesis
• Reproduce sexually
• Has a nucleus, cell membrane, mitochondria, chloroplasts, ribosomes, a big vacuole, DNA, and cell wall

Question 3

Characteristics of fungal cells

Answer 3

• Multicellular organism
• Eukaryotic
• Have hyphae (thread-like cells) which together, make up the body of a fungus called a mycellium
• Heterotrophic as they get energy and nutrients from corpses
• Important as it ensures the nutrients in a corpse are recycled
• Has a nucleus, cell membrane, mitochondria, ribosomes, vacuole, DNA, and cell wall
• Reproduce sexually or asexually

Question 4

Characteristics of Monera

Answer 4

• Prokaryotic
• Unicellular
• Autotrophs or heterotrophs
• Lack membrane-bound organelles (organelles with a membrane)
• Reproduce asexually
• Sometimes photosynthesize
• Motile as they have flagellums
• Have cell membranes, capsules, ribosomes, vacuoles, DNA, and cell walls

Question 5

Characteristics of protists

Answer 5

• Unicellular
• Eukaryotic
• Heterotrophic or autotrophic
• Sometimes use photosynthesis
• Reproduce sexually or asexually
• Motile
• Live in aquatic habitats
• Usually doesn’t have a capsule
• Has a nucleus, cell membrane, mitochondria, sometimes chloroplasts, ribosomes, vacuole, and DNA

Question 5

Characteristics of viruses

Answer 5

• Acellular
• Considered abiotic as they lack some of the characteristics
• Have DNA and RNA genomes
• Causes diseases
• Require living hosts for its survival
• Have capsules and DNA or RNA

Question 5

What are eukaryotes and prokaryotes

Answer 5

• Eukaryotes have a nucleus and membrane-bound organelles
• Include plant, animal, fungal, and protist cells
• Prokaryotes have no nucleus and genetic info is found around the cell
• No membrane-bound organelles
• Include Monera cells

Question 6

What are specialised cells

Answer 6

• Made for a specific purpose in an organism
• Found in multicellular organisms

Question 7

What is cell specialisation/differentiation

Answer 7

• Process in which cells in multicellular organisms become specialised for specific tasks

Question 8

What are stem cells and why are they important

Answer 8

• Undifferentiated cells that have the potential to develop into a wide range of cells

Self-renewal: can make more of themselves infinitely whereas specialised cells can only duplicate 50x before cell death

Specialisation: can specialise into specific cells

Involved in: development, repair, regeneration

Question 9

Process of specialisation for stem cells

Answer 9

Totipotent (can become any kind of cell) –>
Pluripotent (can become practically any cell) –>
Multipotent (can become a limited range of cells)

Question 10

Explain the two main types of stem cells

Answer 10

Embryonic stem cells (ESCs)
- Found in early embryos
- Pluripotent

Adult stem cells:
- Found in tissues throughout life
- Multipotent
- Tissue maintenance and repair
- Common in tissues with constant renewal
- Can only produce cells of the tissue they are in

Question 11

Potential of stem cell application

Answer 11

• Understanding diseases
• Making new treatments
• Cell-based therapies and replacing damaged tissues and organs

Question 12

What are some of the ethical concerns of stem cell application

Answer 12

• Killing a living thing: Obtaining stem cells from embryos will end up killing a living thing
• Consent: sometimes, donors donated egg cells not knowing that it will end up being used for stem cell research
• Cloning: in cloning for stem cells, people worry about questioning their individuality and uniqueness

Question 13

Tell me about some of the organelles found in both eukaryotes and prokaryotes

Answer 13

Genetic material

Cell membrane:
- Semipermeable, select molecules can enter and exit
- Keeps cell stable; known as maintain homeostasis

Ribosomes:
- Make proteins, made of chains of amino acids (process known as synthesizing)
- A lot of genetic material codes for proteins
- Can be free in the cytoplasm or stuck to another organelle

Cytoplasm:
- Jelly-like substance
- Surrounds internal cell structures

Question 14

Tell me about the membrane-bound organelles

Answer 14

Nucleus:
- Have chromatin (tangled, spread-out form of DNA)
- Where genetic material in eukaryotes is put
- Controls cell’s activities
- Has nucleolus where ribosomes are produced

Endoplasmic reticulum:
- Attached to nuclear membrane (membrane of nucleus)
- Does a lot of processing of molecules like protein folding
- Highly involved in transporting those molecules around
- There is a rough and smooth ER
- Rough ER has ribosomes attached to it and focuses on protein production
- Smooth ER doesn’t and has other roles like detoxification and making some types of lipids
- Molecules sent off by rough rough ER comes in small sacs called vesicles

Golgi apparatus:
- Packaging centre
- Receive vesicles from ER
- Has enzymes that can modify molecules
- Determines where to send those molecules

Mitochondria:
- Powerhouse of the cell
- Utilises cellular respiration to make ATP energy from glucose and oxygen
- ATP stands for Adenosine Triphosphate

Question 15

How does cloning for stem cells work

Answer 15

• Take patient’s cell and donated egg cell with nucleus taken out to make embryo (makes it so that the genetic info is similar to the patient’s cell so that it won’t get rejected)
• Through nuclear transfer, the patient cell and the egg cell are combined
• This makes the egg cell develop into an embryo which has embryonic stem cells which which are immunologically compatible

Question 16

What is a cytoskeleton

Answer 16

• Collection of fibers including microfilaments (made of protein) and microtubules
• Provide support for the cell and its organelles
• Organization varies in different cells

Question 17

What are lysosomes

Answer 17

Garbage collectors that take in damaged and worn out cell parts and use enzymes to break them down into cellular debris