Being alive

Question 1

What is a cell?

Answer 1

Cells are the basic units of life. They are membrane bound structures that contain all the materials for life.

Question 2

What order is the living world organised in? (simple to complex)

Answer 2

Chemical (atoms)
Cellular (Cells)
Tissue (Group of same type of cells)
Organs (Body parts)
Organ systems
Organisms (Unicellular and multicellular)

Question 3

What are Eukaryotic cells?

Answer 3

Eukaryotic cells have a nucleus, have membrane bound organelles and have linear DNA.

Question 4

What are Prokaryotic cells?

Answer 4

Prokaryotic cells do not have a nucleus, do not have membrane bound organelles and have circular DNA. An example in Bacteria.

Question 5

What happens to the surface area : volume ratio as cells get bigger and how does this affect the cell?

Answer 5

As the cell gets bigger, the surface area is relatively smaller than the cell’s volume which limits the exchange of materials that can occur between the cell and its surroundings

Question 6

Why are cells so small? (In relation to surface area : volume ratio)

Answer 6

Cells are small so that their surface area is relatively larger than the volume, which allows more material to enter the cell faster and waste products to move out faster. It also allows cells to loose heat quickly. If the cell was large in volume, it would require a lot of material which would not be able to enter the cell due to the lack of surface area.

Question 7

What are stem cells?

Answer 7

cells in their primary stage that can develop into other specific cells when the body needs them later on.

Question 8

What are specialised cells?

Answer 8

cells that perform specialised and particular functions

Question 9

What are organisms?

Answer 9

anything that can live on its own

Question 10

What are plants? (in relation to 5 kingdom classification)

Answer 10

multicellular organisms that are autotrophic (produce their own food through photosynthesis) and have a cell wall made of cellulose and chloroplasts

Question 11

What are animals? (in relation to 5 kingdom classification)

Answer 11

multicellular organisms that are heterotrophic and lack a cell wall, can do complex movement, have nervous coordination and a glycogen store.

Question 12

What is fungi? (in relation to 5 kingdom classification)

Answer 12

multicellular or unicellular organisms that are heterotrophic (obtain their food by absorbing nutrients from other organisms) and have a cell wall made of chitin and a glycogen store.

Question 13

What are protists? (in relation to 5 kingdom classification)

Answer 13

dustbin kingdom, unicellular or simple multicellular organisms that have a nucleus and other membrane-bound organelles.

Question 14

What is monera? (in relation to 5 kingdom classification)

Answer 14

unicellular organisms that lack a true nucleus and other membrane-bound organelles, have one circular chromosome and a slime layer. Examples include bacteria

Question 15

What are viruses?

Answer 15

microscopic infectious agents that can only replicate inside the living cells of other organisms. They consist of a small amount of genetic material, either DNA or RNA, surrounded by a protein coat called a capsid.

Question 16

Why are viruses not considered as living organisms?

Answer 16

Viruses are not considered living organisms because they cannot carry out metabolic processes on their own, and they require a host cell to reproduce.

Question 17

What is an example of a virus?

Answer 17

COVID-19 or HIV

Question 18

What are the two types of viral reproduction?

Answer 18

Lytic cycle and Lysogenic cycle

Question 19

How do viruses reproduce through the lytic cycle ?

Answer 19

-The virus attaches to the host cell and injects its genetic material.
-The viral genetic material takes over the host cell’s machinery to produce more viruses.
-The host cell is forced to replicate the viral genetic material and produce viral proteins, which assemble into new viruses.
-The new viruses are released from the host cell, which often dies in the process.
-The new viruses then go on to infect other cells.

Question 20

How to viruses reproduce through the lysogenic cycle?

Answer 20

-The virus attaches to the host cell and injects its genetic material.
-The viral genetic material integrates into the host cell’s DNA and becomes part of the host cell’s genome.
-The host cell continues to replicate normally, but with the viral genetic material also being replicated and passed on to daughter cells.
-Under certain conditions, such as stress or damage to the host cell’s DNA, the viral genetic material can become activated and enter the lytic cycle, leading to the production of new viruses and cell death.

Question 21

What are pathogens? (give examples)

Answer 21

any organism that can cause a communicable disease to its host organism. examples: bacteria, viruses, fungi, parasites

Question 22

What are homologous structures? (give example)

Answer 22

body parts that are similar in structure but may have different functions. usually found in organisms that share a common ancestor, indicating that they evolved from a common structure in the ancestor but adapted to different functions in different descendants.

examples: the wings of birds, the arms of humans, the fins of whales, and the legs of dogs

Question 23

What are analogous structures?

Answer 23

body parts that have similar functions but have different underlying structures. usually found in organisms that do not share a recent common ancestor but evolved to adapt to similar environments or perform similar functions.

examples: the wings of birds and the wings of bees

Question 24

What is adaptation?

Answer 24

process by which an organism becomes better suited to its environment through inherited characteristics that enhance its survival and reproductive success.

Question 25

What is structural adaptation?give examples

Answer 25

changes in the physical structure or anatomy of an organism that allow it to better survive in its environment. examples of structural adaptations include the wings of birds, the webbed feet of ducks, and the long necks of giraffes.

Question 26

What is behavioural adaptation? give examples

Answer 26

changes in an organism’s behaviour that allow it to better survive in its environment. examples of behavioural adaptations include migration, hibernation, and social behaviours such as pack hunting.

Question 27

What is physiological adaptation? give examples

Answer 27

changes in an organism’s biochemical or physiological processes that allow it to better survive in its environment. examples of physiological adaptations include the ability of camels to store water in their humps, the ability of some animals to change color to blend in with their surroundings, and the ability of certain plants to tolerate extreme temperatures or salt levels.

Question 28

What is health?

Answer 28

state of physical, mental, and social well-being, and not just the absence of disease or infirmity.

Question 29

What are antibiotics

Answer 29

medications that are used to treat bacterial infections. they work by either killing bacteria or preventing their growth and reproduction.

Question 30

What are antibodies?

Answer 30

proteins produced by the immune system in response to the presence of foreign substances, such as viruses, bacteria, and other pathogens. antibodies are part of the body’s defense mechanism against infection and disease.

Question 31

What is antibiotic resistance?

Answer 31

phenomenon where bacteria develop the ability to survive exposure to antibiotics that were previously effective in killing them or inhibiting their growth. occurs when bacteria undergo genetic mutations or acquire resistance genes from other bacteria, allowing them to resist the effects of antibiotics.

Question 32

What are superbugs? (in relation to antibiotic resistance)

Answer 32

bacteria that are resistant to multiple types of antibiotics. this can make it difficult or even impossible to treat certain infections, and can increase the risk of complications, hospitalization, and death.

Question 33

What are vaccines?

Answer 33

harmless form of the disease-causing agent, such as a weakened or inactivated virus or a piece of its protein, into the body. this triggers an immune response that produces antibodies to fight off the disease if the person is exposed to it in the future.

Question 34

What is immunisation?

Answer 34

process of making an individual immune or resistant to a specific infectious disease by administering a vaccine

Question 35

What are harmful micro-organisms? give examples

Answer 35

harmful microorganisms, also known as pathogenic microorganisms, are microorganisms that can cause disease or infection in humans, animals, or plants. they include various types of bacteria, viruses, fungi, and parasites.

Question 36

What are helpful micro-organisms? (give examples)

Answer 36

microorganisms that provide benefits to humans, animals, or plants. examples:
probiotics: these are beneficial bacteria that live in the human gut and help maintain digestive health.

decomposers: these are bacteria and fungi that break down dead organic matter and recycle nutrients back into the ecosystem.

nitrogen-fixing bacteria: these are bacteria that convert atmospheric nitrogen into a form that plants can use for growth.

yeasts: these are fungi that are used in the production of bread, beer, wine, and other fermented foods.

algae: fungi that helps in producing oxygen