EOY Revision (Paper 1) 🔬🦠

Question 1

State the definition of a nucleus?

Hint: contains cell genetics.

Answer 1

contains the cell’s genetics (in the form of DNA), and so controls the cell’s activities

Question 2

What are the 3 main reasons for needing new cells?

Answer 2

1) growth
2) repair
3) development

Question 3

In a cell, where are proteins made?

Answer 3

ribosomes

Question 4

State the defeniton of cytoplasm

Hint: nutrients + salts.

Answer 4

A jelly-like material containing nutrients and salts. (This is where chemical reactions take place)

Question 5

State the role of the mitochondria

Answer 5

• aerobic respiration
• to release energy, for the cell to use

Question 6

Are bacteria unicellular or multicellular. Also, what does unicellular mean?

Answer 6

1) Bacteria are unicellular
2) unicellular- only consists of a single cell

Question 7

What are the adaptations that a sperm cell has? [2]

Answer 7

• lots of mitochondria that releases energy in respiration. This provides the energy needed for the sperm to swim to the egg.
• flagellum so the sperm cell can swim through the uterus + fallopian tube, to reach the egg.
• sperm cell is streamlined, so it can swim.
• lots of digestive enzymes, that are used to break into the egg when the sperm reaches it.

Question 8

What is differentiation?

Answer 8

The process by which cells change to become specialised.

Question 9

What are the disadvantages of using stem cells?

Answer 9

• requires embryonic stem cells (ethical issues)
• body can reject stem cells, because it treats them as a foreign object.

Question 10

What are the risks of using stem cells in medicine?

Answer 10

• virus transmission
• tumor development- this is because the could divide uncontrollably

Question 11

What is diffusion?

Hint: molecules

Answer 11

The movement of molecules from an area of a higher concentration, to an area of a lower concentration

Question 12

What is osmosis?

Answer 12

The movement of water particles across a selectively permeable membrane, from an region of high water concentration, to a region of a low water concentration

Question 13

What is active transport?

Hint: against the concentration gradient

Answer 13

The movement of dissolved molecules into, or out of a cell through a cell membrane, from a region of lower concentration to a higher concentration.

In active transport, the particles move against the concentration gradient by using energy that is released in respiration.

Question 14

How are root hair cells adapted for their function?

Answer 14

Root hair cells have lots or mitochondria, to release energy needed for active transport.

Question 15

Cross out the incorrect word. As organisms get larger,

Surface area: volume increases/decreases

Answer 15

Answer: decreases

Question 16

BACTERIA VS HUMANS

Hint: include surface area + volume ratio in answer

Hint #2: include high+ low

Answer 16

Bacteria:

• high surface area to volume ratio
• can rely on diffusion across their surface area, to exchange everything they need.

Humans:

• Whilst in humans, they have a low surface area to volume ratio
• And humans can’t rely on diffusion + needs specialised exchange cells.

Question 17

TRUE OR FALSE: Almost all larger multicellular organisms often have larger organisms, to transport substances to parts of the body that need them.

Answer 17

Answer: true

Question 18

What is an exchange surface?

Hint: substances are exchanged over the environment

Answer 18

A part of an organism over which substances are exchanged over with the environment.

Question 19

What are some of the features that specialised exchange surfaces have?

Hint: surface area, membrane

Answer 19

• permeable membrane
• large surface area : volume (to volume)
• very thin membrane
• needs a diffusion gradient.

Question 20

What are the adaptations that a root hair cell has for exchanging substances?

Answer 20

• A root hair cell has lots of mitochondria to take in mineral ions, for active transport.
• A root hair cell has large surface area to help with efficient absorption of water + mineral ions.