Cells

Question 1

Chloroplasts

Answer 1

Structure: A double plasma membrane surrounds the organelle with stacks of thylakoids with chlorophyll

Function: Site of photosynthesis

Question 2

Mitochondrion

Answer 2

Structure: Rod shaped organelle with a double membrane - inner membrane folded to form cristae

Function: Site of aerobic respiration & formation of ATP molecule

Question 3

Nuclear Pores

Answer 3

Structure: Holes within the double nuclear membrane

Function: Allows the passage of large molecules e.g mRNA out of nucleus

Question 4

Nucleus

Answer 4

Structure: Double membrane with pores has nucleolus and chromosomes, with the nucleoplasm, which is granular, jelly-like material

Function: Contains hereditary material and controls the cells activities by coding for protein synthesis

Question 5

Rough Endoplasmic Reticulum

Answer 5

Structure: System of sheet-like membranes spreading across the cytoplasm and continues with nuclear membrane, ribosomes attached. Enclosing a network of tubules & flattened sacs called cisternae

Function: Provides large SA for synthesis of proteins and glycoproteins pathway for proteins through cell

Question 6

Smooth Endoplasmic Reticulum

Answer 6

Structure: System of sheet-like membranes spreading across the cytoplasm and continues with nuclear membrane. Enclosing a network of tubules & flattened sacs called cisterns

Function: Synthesis, store & transport of lipids and carbohydrates

Question 7

Ribosomes

Answer 7

Structure: Very Small cytoplasmic granules with 2 sub units 1 large 1 small each made of rRNA and protein, no membrane.

Function: Site of protein synthesis

Question 8

Golgi Apparatus

Answer 8

Structure: A sac of fluid-filled membranes that makes up flattened sacs called cisterns with small, round hollow structures called vesicles

Function: Forms glycoproteins. Produces secretory enzymes eg in pancreas secrete carbohydrates

Question 9

Vacuole

Answer 9

Structure: Filled with water and solutes (mineral salts, sugars, amino acids, wastes & pigments). Tonoplast membrane.

Function: Supports herbaceous plants by making cells turgid sugars and amino acids may act as temporary food sources

Question 10

Nuclear Envelops

Answer 10

Structure: A double membrane surrounding the nucleus

Function: Controls entry & exit of materials in and out of the nucleus and contains reactions taking place within it

Question 11

Nucleolus

Answer 11

Structure: small, spherical region in the nucleoplasm

Function: Manufacturers rRNA and assembled ribosomes

Question 12

Cell Wall

Answer 12

Structure: Microfibrils of the polysaccharide, cellulose, embedded in a matrix. It has a middle lamella which marks the boundary between adjacent layers. Found in algal cells but made of CHITIN

Function: Provides mechanical strength to prevent the cell bursting. Allows water to move along the whole plant

Question 13

Plasma Membrane

Answer 13

Structure: Fluid mosaic structure of phospholipids. Microvilli increases SA

Function: Controls the transport of substances into and out of the cell, recognition and receptor sites

Question 14

Lysosome

Answer 14

Structure: Round organelle (vesicles) containing enzymes, surrounded by a membrane, with digestive enzymes. Formed by Golgi apparatus

Function: Hydrolyse material ingested by phagocytic cells. Release enzymes to the outside of the cell in order to destroy material around the cell. Completely break down cells after they have died