Cell Structure 2.1.1

Question 1

Role of the nucleus

Answer 1

Surrounded by a double membrane called the nuclear envelope containing pores which enables molecules to enter and leave the nucleus. Contains genetic information of the cell and the activities of the cell.

Question 2

Role of the cell surface (plasma) membrane

Answer 2

Controls what enters and leaves the cell, it is a phospholipid bilayer, it also contains protein channels.

Question 3

Role of the mitochondria

Answer 3

Site of aerobic respiration, releases energy for the cell’s movement.

Question 4

Role of the ribosomes.

Answer 4

Site of protein synthesis.

Question 5

Role of the cytoplasm.

Answer 5

Where chemical reactions occur in the cell.

Question 6

Role of chromatins

Answer 6

Package long DNA molecules into more compact, denser structures.

Question 7

Role of nucleolus

Answer 7

Produces and assembles the cell’s ribosomes.

Question 8

Role of lysosomes.

Answer 8

Is a vesicle containing digestive enzymes bound by a single membrane.

Question 9

Role of the centrosome matrix

Answer 9

Centrosomes help in cell division, they maintain the chromosome number during cell division, they also stimulate the changes in the shape of the cell membrane by phagocytosis. In mitosis it helps in organising the microtubules ensuring the centrosomes are distributed to each daughter cell.

Question 10

Role of peroxisomes

Answer 10

Specialised for carrying out oxidative reactions using molecular oxygen.

Question 11

Role of the rough endoplasmic reticulum

Answer 11

A series of flattened sacs enclosed by a membrane with ribosomes on the surface. RER folds and processes proteins made on the ribosomes.

Question 12

Role of the smooth endoplasmic reticulum.

Answer 12

Is a system of membrane bound sacs. SER produces and processes lipids.

Question 13

Role of the secretory vesicle

Answer 13

Moves molecules outside the cell through a process called exocytosis.

Question 14

Role of the cilia

Answer 14

Help move entire cells or can move substances along the outer surface of the cell.

Question 15

Role of the intermediate filaments

Answer 15

Provide structure and support for the cells.

Question 16

Role of the micro filaments

Answer 16

Also provide support to cells but are smaller.

Question 17

Role of the cytosol

Answer 17

It is involved in signal transduction between the cell membrane and the nucleus and organelles. It transports metabolites from their production site to other parts of the cell. It is important for cytokinesis, when the cell divides in mitosis.

Question 18

Role of the centrioles

Answer 18

They are hollow cylinders containing a ring of microtubules arranged at right angles to each other. They are also involved in cell division.

Question 19

Role of microvilli

Answer 19

Increase the surface area in order to absorb more nutrients.

Question 20

Role of the microtubules

Answer 20

They function both to determine cell shape and in a variety of cell movements, including some forms of cell locomotion, the intracellular transport of organelles, and the separation of chromosomes during mitosis.

Question 21

Role of the nuclear envelope

Answer 21

separates the contents of the nucleus from the cytoplasm and provides the structural framework of the nucleus. The nuclear membranes, acting as barriers that prevent the free passage of molecules between the nucleus and the cytoplasm, maintain the nucleus as a distinct biochemical compartment.

Question 22

Role of the Golgi apparatus

Answer 22

Packages proteins into vesicles to be transported around the cells to where they’re required. Some of the proteins such as extracellular enzymes leave the cell by exocytosis.

Question 23

Role of the permanent vacuole

Answer 23

Found in plants. A single membrane sac filled with fluid containing salts, sugars, and amino acids. The membrane around a cell vacuole is called the tonoplast. To provide support to a cell, store amino acids and sugars, and can contain pigments to attract pollinators.

Question 24

Role of the cell wall

Answer 24

The cell wall separates the interior contents of the cell from the exterior environment. It also provides shape, support, and protection to the cell and its organelles. However, this cellular component is present exclusively in eukaryotic plants, fungi, and a few prokaryotic organisms. Made of peptidoglycan.

Question 25

Role of chloroplasts

Answer 25

They have a double membrane and are the site of photosynthesis, they contain thylakoids which contain chlorophyll. Chlorophyll is the green pigment used in photosynthesis as it attracts the sunlight.

Question 26

Role of tonoplasts

Answer 26

Is a membrane which surrounds the vacuole which functions to separate the vacuole from the rest of the cell.

Question 27

Role of amyloplasts

Answer 27

An organelle found in only plant cells that produces, breaks down and stores starch.

Question 28

Role of pits

Answer 28

Thin areas on the secondary walls of plants, they aid in the transport of minerals and water between the cells

Question 29

Role of plasmodesmata

Answer 29

They are small channels that directly connect the cytoplasm of neighbouring plant cells.

Question 30

Role of the capsule - prokaryotic

Answer 30

Protective slimy layer which helps the cell to retain moisture and adhere to surfaces.

Question 31

Role of plasmids

Answer 31

Circular piece of DNA

Question 32

Role of the flagellum

Answer 32

A tail like structure which rotates to move the cell

Question 33

Role of the pili

Answer 33

Hair like structures which attach to other bacterial cells.