3.2.1.1 Eukaryotic Cells

Question 1

What is the structure of the nucleus?

Answer 1

Contains hereditary material
Nuclear envelope: double membrane, outer membrane is continuous with the ER, controls the entry and exit of material
Nuclear pores: allows the passage of large molecules out of the cell
Nucleoplasm
Chromosomes: protein bound DNA
Nucleolus: makes ribosomal RNA, assembles ribosomes
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Question 2

Mitochondria?

Answer 2

Double membrane which controls the entry and exit of material
Cristae: extensions of the inner membrane, large surface area for respiration
Matrix: contains all the substances needed for respiration
Creates ATP
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Question 3

What are chloroplasts?

Answer 3

The organelle which carries out photosynthesis

Question 4

What is the structure of chloroplasts?

Answer 4

Chloroplast envelope: double membrane, controls the entry and exit of material
Grana: stacks of thylakoids
Thylakoids: contains chlorophyll, some have extensions between adjacent grana
Stroma: fluid filled matrix, possesses all the enzymes needed for photosynthesis
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Question 5

How are chloroplasts adapted for photosynthesis?

Answer 5

Granal membranes provide a large surface area
Fluid possesses all the enzymes needed for sugar production
Contain both DNA and ribosomes to manufacture the proteins needed for photosynthesis

Question 6

What is the Golgi apparatus?

Answer 6

Flattened sacs or cisternae
Vesicles bring material from the ER
Processes and packages material
Produces secretory enzymes
Transports, modifies and stores lipids
Forms lysosomes
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Question 7

What are ribosomes?

Answer 7

Two subunits
Contains RNA and protein
Site of protein synthesis
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Question 8

What is the difference between ribosomes in eukaryotic and prokaryotic cells?

Answer 8

80S: eukaryotic
70S: prokaryotic, found in mitochondria and chloroplasts

Question 9

What is the smooth endoplasmic reticulum?

Answer 9

Lacks ribosomes

Synthesises, stores and transports lipids and carbohydrates

Question 10

What is rough endoplasmic reticulum?

Answer 10

Has ribosomes present on the outer surface of the membrane

Large surface area for the synthesis of proteins

Question 11

What are lysosomes?

Answer 11

Hydrolyses material ingested by phagocytes
Exocytosis to destroy material
Digests worn out organelles
Autolysis
Contains lysozymes which hydrolyse cell walls

Question 12

What is the cell wall?

Answer 12

Found in all plant cells
Consists of microfibrils of cellulose
Middle lamella marks the boundary between cell walls
Stops the cell bursting under osmotic pressure
Strengthens the plant cell
Allows the movement of water

Question 13

What is a cell vacuole?

Answer 13

Fluid filled sac
Single membrane called a tonoplast
Contains pigments to attract pollinating insects
Temporary food store

Question 14

What is a tissue?

Answer 14

A group of similar cells that perform a specific function

Question 15

What is epithelial tissue?

Answer 15

It consists of sheets of cells
It lines the surface of organs
Most have a protectors or secretory function

Question 16

What is xylem tissue?

Answer 16

Found in plants
Used to transport water and mineral ions through the plant
Gives mechanical support

Question 17

What is an organ?

Answer 17

A structure composing of two or more tissues which undergo one major function

Question 18

What is an organ system?

Answer 18

A group of organs working together to perform a particular function

Question 19

What is connective tissue?

Answer 19

The supporting tissue of the body

It binds structures together to provide support and protection against damage/infection/heat loss