Eukaryotic cells

Question 1

structure of golgi

Answer 1

compact structure formed of cisternae and does not contain ribosomes

Question 2

smooth endoplasmic reticulum

Answer 2

responsible for lipid and carbohydrate synthesis and storage

Question 3

rough endoplasmic reticulum

Answer 3

has ribosomes bound to the surface and is responsible for the synthesis and transport of proteins

Question 4

function of golgi

Answer 4

role in modifying proteins and packaging them into vesicles

Question 5

structure of nucleus

Answer 5

Large organelle surrounded by a nuclear envelope (membrane), which contains many pores.

Question 6

what does the nucleus contain, which is involved in the cell cycle?

Answer 6

Contains chromatin, which is made from DNA and proteins.This coils and condenses to form chromosomes.

Question 7

function of a nucleus

Answer 7

-contains genetic material in the form of DNA molecules - which directs synthesis of proteins
-controls cells activities

Question 8

function of a nucleolus

Answer 8

produces ribosomes

Question 9

What is the nucleolus composed of, what is then used to produce?

Answer 9

• composed of proteins and RNA.
• RNA is used to produce ribosomal RNA, which is then combined with proteins to form ribosomes needed for protein synthesis.

Question 10

structure of mitochondria

Answer 10

• Oval shaped.
• Has double membrane- inner one is folded to form structure called cristae.
• Inside is matrix, which contains enzymes involved in respiration.

Question 11

function of mitochondria

Answer 11

• Site of aerobic respiration, where ATP is produced.
• Due to being very active, requires a lot of energy.

Question 12

structure of vesicles

Answer 12

• A small fluid-filled sacs in the cytoplasm, surrounded by a membrane.

Question 13

Function of vesicles

Answer 13

• Transports substances in and out of the cell (via plasma membrane) and between organelles

Question 14

Structure of lysosome

Answer 14

A round organelle surrounded by a membrane, with no clear internal structure.

Question 15

function of lysosome

Answer 15

• Contains digestive enzymes (known as hydrolytic) which is used to digest invading cells or to break down worn out components of the cell.

Question 16

What is the cytoskeleton?

Answer 16

• A network of fibres necessary for the shape and stability of the cell.

Question 17

what are microfilaments?

Answer 17

• Contractile fibres formed from the protein actin.

Question 18

what do microfilaments do?

Answer 18

• Give support and mechanic strength.
• Allows cells to move and contract during cytokinesis- results in two daughter cells at the end of mitosis.

Question 19

How large are microfilaments?

Answer 19

7nm diameter.

Question 20

What are microtubules made of?

Answer 20

-Made of globular tubulin proteins that polymerise to form tubes that are used to form a scaffold-like structure, which determines shape of cell.

Question 21

How big are microtubules?

Answer 21

-About 18-30nm diameters.

Question 22

What does microtubules do?

Answer 22

-provide strength and support to the cell
-help to move organelles through cytoplasm from one part of the cell to another
- Forms a “track” for organelles and vesicles to move along
- Make up spindle for chromosomes movement during meiosis/mitosis
- They also make up cilia, flagella and centrioles.

Question 23

How big are intermediate fibres?

Answer 23

About 10nm diameter.

Question 24

what does intermediate fibres do?

Answer 24

-Extend in between cells, helping to anchor cells in place together, stabilising structure of tissues.

Question 25

Structure of centrioles

Answer 25

• Small, hallow cylinders, made of microtubules
• Found in animal cells, but some plant cells

Question 26

function of centrioles

Answer 26

-Involved in separation of chromosomes during cell division.
-Two associated centrioles form the centrosome, which is involved in the assembly and organisation of the spindle fibres during cell division.

Question 27

Structure of flagella

Answer 27

-stick out as long projections from the cell, and have membranes around them.

Question 28

Function of flagella

Answer 28

• They allow the whole cell to move e.g. the flagellum on the sperm cell.

Question 29

What are cilia?

Answer 29

-These are attachments to the cell surface membrane.

Question 30

What does cilia do?

Answer 30

-They “beat” in a co-ordinated way to move substances over the surface of the cell.
E.g. found on the cells lining of the airways - sweep mucus up and away from the lungs to the back of the throat.

Question 31

what is the endoplasmic reticulum?

Answer 31

Network of membranes enclosing flattened sacs called the cisternae and connected to the outer membrane of the nucleus.