Module 2 : cell structure

Question 1

Name the organelles present in animal cells

There are 11

Answer 1

Plasma membrane 
Cytoplasm 
Ribosomes 
Lysosomes 
Mitochondria 
Nucleus
Nucleolus 
Nuclear envelope 
Rough endoplasmic reticulum 
Smooth endoplasmic reticulum
Golgi apparatus

Question 2

Name the organelles present in plant cells

There are 14

Answer 2

Plasma membrane 
Cell wall 
Cytoplasm 
Vacuole 
Mitochondria 
Chloroplast
Plasmodesmata 
Ribosomes
Rough endoplasmic reticulum 
Smooth endoplasmic reticulum 
Nucleus 
Nucleolus 
Nuclear envelope 
Golgi apparatus

Question 3

Which organelles are present in plant cells but not animal cells?

Answer 3

Plasmodesmata
Chloroplast
Cell wall

Question 4

Describe the structure and function of plasma membranes

Answer 4

Structure: found on the surface of animal cells and just inside the cell wall of plant cells and prokaryotic cells. Made of phospholipids and proteins.

Function: regulates the movement of substances into and out of the cell. It also has receptor molecules of cell communication and to respond to chemicals like hormones.

Question 5

Describe the structure and function of the cell wall

Answer 5

Structure: a rigid structure that surrounds plant cells. It’s made mainly of cellulose

Function: supports plant cells

Question 6

Describe the structure and function of the nucleus

Answer 6

Structure: a large organelles surrounded by a nuclear envelope (double membrane) which contains many pores. The nucleus contains chromatin (made from DNA and proteins) and a structure called the nucleolus.

Function: the nucleus controls the activities of the cell. DNA contains instructions to make proteins. The pores allow substances to move between the nucleus and the cytoplasm. The nucleolus makes ribosomes.

Question 7

Describe the structure and function of the lysosome

Answer 7

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

Function: contains digestive enzymes that are used to digest invading cells or break down worn out componants of the cell.

Question 8

Describe the structure and function of the ribosome

Answer 8

Structure: very small organelle that either floats free in the cytoplasm or is attached to the rough endoplasmic reticulum. It is made up of proteins and RNA. It is NOT surrounded by a membrane.

Function: site of protein synthesis

Question 9

Describe the structure and function of the rough endoplasmic reticulum

Answer 9

Structure: a system of membranes enclosing a fluid-filled space. The surface is covered with ribosomes.

Function: folds and processes proteins that have been made at the ribosomes

Question 10

Describe the structure and function of the Smooth endoplasmic reticulum

Answer 10

Structure: a system of membranes enclosing and fluid-filled spaces. It’s is NOT covered in ribosomes.

Function: synthesises and processes lipids

Question 11

Describe the structure and function of vescicles

Answer 11

Structure: a small fluid-filled sac in the cytoplasm surrounded by a membrane

Function: transports substances in and out of the cell (via the plasma membrane) and between organelles. Some are formed by the Golgi apparatus or the endoplasmic reticulum, while other and formed at the cell surface.

Question 12

Describe the structure and function of the Golgi apparatus

Answer 12

Structure: a group of fluid-filled, membrane-bound, flattened sacs. Vesicles are often seen at the edges of the sacs

Function: it processes and packages the new proteins and lipids. It also makes lysosomes

Question 13

Describe the structure and function of the Mitochondria

Answer 13

Structure: oval shaped and have a double membrane - the inner one is folded to form structures called cristae. Inside is the matrix, which contains enzymes involved in respiration.

Function: the site of respiration where ATP is produced.

Question 14

Describe the structure and function of the Chloroplast

Answer 14

Structure: a small, flattened structure found in plant cells. It’s surrounded by a double membrane. It also has membranes inside called thylakoid membranes. These membranes are stacked up in some parts to form grana. Grana are linked together by lamellae - thin flat pieces of thylakoids membrane.

Function: the site of photosynthesis.

Question 15

Describe the structure and function of the Centriole

Answer 15

Structure: small hollow cylinders made of microtubules. Found in animal cells but only some plant cells.

Function: involved in the separation of chromosomes during cell division

Question 16

Describe the structure and function of the Cilia

Answer 16

Structure: small hair like structure found on the plasma membrane of some animal cells. In cross section, they have an outer membrane and a ring of nine pairs of protein microtubules, with two microtubules in the middle.

Function: the microtubules allow the cilia to move. This movement is used by the cell to move substances along the cell surface

Question 17

Describe the structure and function of the flagellum

Answer 17

Structure: flagellum on eukaryotic cells are like cilia but longer. They stick out from the cell surface and surrounded by the plasma membrane. Inside they are like cilia too - two microtubules in the middle and nine pairs around the edge.

Function: the microtubls contract to make the flagellum move. Flagella are used to proper cells forward