Topic 1 Cells (section 2)

Question 1

What is an organelle?

Answer 1

Intracellular structure that carries out a specific function within a cell

Question 2

What is a cell?

Answer 2

Basic unit from which all organisms are made

Question 3

What is a tissue?

Answer 3

A group of specialised cells which are adapted to carry out a specific function

Question 4

What is an organ?

Answer 4

A group of tissues adapted to perform a specific function

Question 5

What is an organ system?

Answer 5

Group of organs that carry out particular functions

Question 6

What is an organism?

Answer 6

All organs working together in a living ‘thing’

Question 7

What is the cytoplasm?

Answer 7

Site of chemical reactions in cell / jelly like substance

Question 8

What is the cell membrane?

Answer 8

Controls entry and exit of molecules in and out of cell

Question 9

What is the nucleus?

Answer 9

Controls cell’s activities + contains DNA

Question 10

What are mitochondria?

Answer 10

Site of aerobic respiration and release ATP

Question 11

What are chloroplasts?

Answer 11

Site of photosynthesis and contain chlorophyll

Question 12

What is the cell wall?

Answer 12

Strengthens the cell
stops it from bursting
Made of cellulose

Question 13

What is the vacuole?

Answer 13

Contains cell sap
Stores water, sugars and waste
Gives cell its shape

Question 14

What are ribosomes?

Answer 14

Site of protein synthesis

Question 15

What are the similarities between animal and plant cells?

Answer 15

• both contain nucleus, cytoplasm, cell membrane
• both contain ribosomes + mitochondria
• both are eukaryotes (have a nucleus)

Question 16

What are the differences between animal and plant cells?

Answer 16

• plant cells have vacuole, chloroplasts and cell wall

- aren’t present in animal cell

Question 17

Why is cell differentiation important in the development of specialised cells?

Answer 17

Cell differentiation allows cells to develop structures and features that enable them to fulfil specific roles and functions

Question 18

What is the function and structure of the egg cell?

Answer 18

To be fertilised by sperm cell + transfer genetic material to offspring
1. Contains +++ mitochondria (to release energy in respiration)

2. Contains half of mother’s DNA
3. Very large - easier to be fertilised

Question 19

What is the structure and function of sperm?

Answer 19

To swim to + fertilise egg cell, transfer genetic material to offspring
1. Flagellum for swimming, stream lined shape

2. +++ mitochondria to release energy via respiration
3. Acrosome (tip of sperm) contains digestive enzymes -> break down egg membranes
4. Contains 1/2 father’s DNA

Question 20

What is the structure and function of a red blood cell?

Answer 20

Carries o2 around body
1. Haemoglobin -> carry lots of o2

2. Biconcave shape -> large SA:Vol ratio for efficient diffusion
3. No nucleus -> can carry more o2

Question 21

What is the structure and function of a nerve?

Answer 21

Carrie electrical impulses between body + brain

1. Long thin shape -> faster + covers longer distance
2. Myelin sheath to insulate nerve cells + speed up conduction

Question 22

What is the structure and function of a ciliated epithelial cell?

Answer 22

To aft mucus out of airways (mucus traps bacteria/dust)

1. Cilia on surface- hair like structures
2. ++++ mitochondria for energy via respiration

Question 23

What is the structure and function of a small intestine cell?

Answer 23

Releases digestive enzymes and absorbs nutrients from digestion

1. Microvilli - large sa vol ratio for absorption
2. +++ mitochondria = energy for active transport

Question 24

What is the structure and function of a palisade cell?

Answer 24

Carry out photosynthesis

1. ++= chloroplasts -> contain chlorophyll and absorb light for photosynthesis

Produces glucose that can be used for respiration

Question 25

What is the structure and function of a root hair cell?

Answer 25

Absorb water + minerals from soil (water - osmosis, mineral - active transport)

1. Shape gives larger surface area : volume ratio for osmosis /active transport

Question 26

What is the structure and function of a xylem cell?

Answer 26

Transport water + solutes from roots to leaves

1. Cells are dead- long continuous hollow tubes for water to travel fast
2. Cells contain lignin for strength