Eukaryotic cells

Question 1

Cytoplasm

Answer 1

Contains cytosol (jelly-like material in a cell made of proteins and other dissolved substances in water), all the organelles in a cell and enzymes where chemical reactions take place

Question 2

Ribosomes

Answer 2

Consists of two subunits (made of protein and ribosomal RNA) where protein synthesis occurs

Question 3

Cell surface membrane

Answer 3

Made of two layers of phospholipids which separate the contents of the cell from the environment, regulating has movement of substances into and out of the cell

Question 4

Mitochondria

Answer 4

Oval with double membrane (inner folded into cristae - increases SA), where energy is released during aerobic respiration in the form of ATP

Question 5

Golgi apparatus

Answer 5

Stack of fluid filled membrane bound sacs which package molecules into smaller vesicles to be transported, chemically modified or stored in the cell

Question 6

Vesicles

Answer 6

Membrane bound fluid filled sacs which transport and store substances like lipids and proteins

Question 7

Lysosomes

Answer 7

A membrane bound sac containing digestive enzymes and lysozymes so involved in digestion and waste removal

Question 8

Smooth endoplasmic reticulum

Answer 8

Involved in synthesis, transportation and storage of lipids and carbs

Question 9

Rough endoplasmic reticulum

Answer 9

Fluid filled network of membranes with ribosomes on their surface, may finish off the synthesis of proteins but main job is transport the proteins synthesised at the ribosomes throughout the cell

Question 10

Nucleus

Answer 10

A large round organelle containing the genetic material (DNA in the form of chromosomes) of a cell, controls the cells activities, contains the info to make proteins

Question 11

Nucloplasm

Answer 11

Granular, jelly like material which makes up the bulk of the nucleus

Question 12

Nuclear envelope

Answer 12

Double membrane which encloses the nucleus, protecting it from materials in the cytoplasm and controls the entry and exit of materials into and out of the cell

Question 13

Nuclear pore

Answer 13

Allows the exchange of larger materials between the nucleus and cytoplasm eg. RNA

Question 14

Chromatin

Answer 14

Material that makes up chromosomes consists of condensed DNA and histones

Question 15

Nucleolus

Answer 15

Densely packed area of the nucleus containing the DNA and assembles ribosomes

Question 16

Eukaryotic cell

Answer 16

A cell that has a membrane-bound nucleus and chromosomes as well as other membrane bound organelles (mitochondria and ER) examples include animals, plants and fungus

Question 17

Ultrastructure:

Answer 17

Each cell has an internal structure suited for its job

Question 18

What organelle do plant and algae cells also have? What is its structure/function?

Answer 18

Chloroplasts

Question 19

Describe the structure of chloroplasts..

Answer 19

Small, flattened organelles made of a double membrane - the inner called thylakoids, which form coin-like stacks called grana, linked together by lamellae. The thylakoids contain chlorophyll to absorb light energy for photosynthesis
Chloroplasts also contain a chloroplast envelope which surrounds the organelle and is highly selective the molecules it allows to enter and leave the cell

Question 20

What is the function of the chloroplasts?

Answer 20

Photosynthesis takes place in the grana as contains chlorophyll to absorb light and in the stroma (plural stomata) (thick fluid found in the chloroplasts filling the matrix) where the synthesis of sugar takes place

Question 21

How are the chloroplasts adapted to their function of absorbing and harvesting sunlight to carry out photosynthesis?

Answer 21

Granal membranes have a large SA - attachment of chlorophyll and enzymes carrying out photosynthesis
The fluid of the stroma has all the enzymes needed for for the photosynthesis of the sugars
Contain DNA and ribosomes so can quickly make the proteins needed for photosynthesis

Question 22

What organelle do plant cells also have?

Answer 22

Cell vacuole

Question 23

How is the structure of a vacuole linked to its function?

Answer 23

Large sac contains cell sap which maintains the cells turgid state by containing the correct concentration of glucose, amino acids, ions and water to prevent osmosis by maintaining the pressure and concentration gradient, it also acts as a temporary food store

Question 24

What do plant, algae and fungi also have?

Answer 24

A cell wall

Question 25

What does the cell wall do?

Answer 25

Plant and algae walls are made of cellulose, fungi walls are made of chitin but they all provide structural support and protection. Preventing the cell bursting due to changes in the concentration gradient outside the cell also fully permeable allowing substances in and out

Question 26

How do eukaryotic cells become specialised for specific functions?

Answer 26

They differentiate so become specialised to suit the role it is to carry out. The genes are either switched on or off in the DNA of that cell, each cell also possess different number of organelles ta=hat will enable it to carry out its function most efficiently

Question 27

What is a tissue?

Answer 27

A group of similar cells organised into a structural unit that perform a particular function

Question 28

What is an organ?

Answer 28

A combination of tissues that are coordinated to perform a variety of functions or one main function

Question 29

What is an organ system?

Answer 29

Organs working together to perform a particular function

Question 30

What is differentiation?

Answer 30

The process by which cells become specialised for different functions

Question 31

What is the middle lamella?

Answer 31

Layer made up of pectins and other substances found between the walls of adjacent plant cells