2.1 + 2.2

Question 1

WHat are living things made up of

Answer 1

Cells

Question 2

What was cell theory developed in conjunction with

Answer 2

Discovery of Cells

Question 3

What are the four main components of cell theory

Answer 3

-Cells are the structural unit of all living things
- cells are the functional unit of life, carrying out all the living processes
- Every cell arise froma pre-existing cells
- Cells contain hereditary material

Question 4

What are criteria to classify something as living

Answer 4

• are complex and have an organised structure
• take in energy from their surroundings and use it
• maintain a composition that is chemically different from their external environment
• respond to stimulis
• are able to reproduce
• grow and respond

Question 5

What is something that all cells have

Answer 5

A membrane which encloses the cell, the cytoplasm which consists of mainly water and also a small number of structures called organelles

Question 6

Compare compositon of prokaryotic cell as compared to a eukaryotic cell

Answer 6

Prokaryote = non membrane bound organelles, less complex, little internal organisation, smaler, circular DNA, no nucleus, unicellular
Eukaryote = membrane bound organelles, more complex, larger, complex organisation, two or more chromosomes, uni or multicellular

Question 7

The cell membrane is responsible for ….

Answer 7

controlling what enters and exits a cell

Question 8

WHat is the cell membrane comprimised of

Answer 8

a phospholipi bilayer

Question 9

WHat is the role of the cell membrane

Answer 9

Seperates the contents of the cell from the external environment

regulate the passage of substances into and out of the cell

enables cells to recognise one another and to recognise certain substances, such as hormones

enable attachment of the cytoskeleton

Question 10

How can the structure of the cell membrane be explained and why

Answer 10

A fluid mosaic model as it is islands of protein floating in a sea of lipids.

This term suggests that it’s fluid nature means that it is a dynamic living structure, rather than a static

The term mosaic encompasses the idea that the structure is made up of many components

Question 11

What are common features found in both prokaryotes and eukaryotes

Answer 11

Both have a phospholipid bi layer cell membrane, ribosomes, chromosomes containign DNA and similar protein synthesis mechanisms

Question 12

What does similarities in protein synthesis mechanisms betwene prokaryotes and eukarytoes suggest

Answer 12

Common evolutionary past

Question 13

What does the nucleus control

Answer 13

All cell activities, as it determines which proteins are to be made via protein synthesis and therefor determines the structure and function (enzymes) of the cells

Question 14

Describe the composition of the nuclues

Answer 14

Contained by a double membrane called the nuclear envelope, which contains nuclear pores that allow substances such as mRNA to leave the nucleus.

Within the nucleus is one or more nuclei which is where RNA is synthesised

Question 15

What is the role of the mitochondria

Answer 15

Are where the latter stages of aerobic respiration occurs

Question 16

What type of cells require higher numbers of mitochondria

Answer 16

Cells such as muscle cells and sperm cells require a larger number of mitochondria.

Question 17

Describe the composition of the mitochondria

Answer 17

Double membrane. The inner membrane is folded forming a structure called cristae which increases surface area, allowing for efficient synthesis of ATP energy

Question 18

Describe the role of chloroplasts

Answer 18

Double membraane bound organelle involved in the synthesis and storage of food and is commonly found within the cells of photosynthetic organisms like plants

Question 19

Describe the compositon of chloroplasts

Answer 19

Double membrane. Within the membrane are flattened membrane sacs called thykaloids which contain the chemical chlorophyll. These thykaloids are stacked into columnns called grana. The fluid that surrounds them is called stroma

Question 20

Describe the function of vacuoles

Answer 20

They are used in the control of water and salt balance. Plant cells have large vacuoles, helping to maintain the cell’s structure and shape. Some unicellular fresh-water organisms have contractile vacuoles which are able to remoe excess water that enters the cell. SOme cells use vacuoles to store waste products.

Question 21

Describe the structure of vacuoles

Answer 21

Fluid filled spaces surrounded by a membrane. They can contain solutes such as salts, sugars and amino acids.

Question 22

What is a small vacuole called and what are they used for

Answer 22

Vesicles and are used in endo and exocytosis. Specialised vesicles called lysosomes contain digestive enzymes

Question 23

Describe the function of the golgi apparatus

Answer 23

They are involved in the packaging and secretion of proteins and carbohydrates made by the cell.

Question 24

What’s an example of a type of cell that has a large number of golgi bodies

Answer 24

Salivary glands as they help to package adn secrete salivary amylase

Question 25

Describe the structure of th golgi body

Answer 25

Stacks of flattened smooth membrane saces

Question 26

Describe the function of the endoplasmic reticulum

Answer 26

System of tubules that run from the nuclear envelope to the cell membrane. It helps to transport materials throughout the cell

Question 27

What is the difference between the smooth and rough endoplasmic reticulums

Answer 27

Rough ER has attached ribosomes - it iws where protein and membrane synthesis occurs. Smooth ER is involved in the synthesis of lipids and the metabolism of carbohydrates

Question 28

Describe the structure of ribosomes

Answer 28

Made up of two sub-units which are comprised of RNA and protein. Ribosomal protein is produced in the nucleolus. They are non-membrane bound. Found in both pro and eu karyotes

Question 29

WHat is the function of the ribosomes

Answer 29

Site of translation in protein synthesis

Question 30

What is the function of lysosomes

Answer 30

Specialised vesicles containing digestive enzymes to help breakdown and digest materials and invaders in the cell

Question 31

What is the role of the cytoskeleton

Answer 31

Giving cells their shape
Being involed in cell movement (spindle apparatus moves chromosomes)
Holds organelles in place
Provides strnegth to the cell

Question 32

What are the three main components of the cytoskeleton

Answer 32

Micro-filaments (actin), microtubules (tubin) and intermediate filaments

Question 33

What is the role of the micro-filaments

Answer 33

Used in cell movement such as chloroplast orientation, pinching of the cell to form daughter cells, formation fo food vacuoles (phagocytosis)

Question 34

What is the role of the micro-tubules

Answer 34

Allows the movement of the flagella and cilia. Also used in cells to hold organelles in places (e.g. move chloroplasts to the sunny side of the leaf)

Question 35

What is the role of the intermediate filament

Answer 35

Provide strength for cells, especially in cells prone to wear and tear such as skin cells

Question 36

Give some examples of the role the cytoskeleton plays in specific cells

Answer 36

Red-blood cell - bi-concave shape increases SA:V ratio
Nerve cell - long axon
Specialised surfaces - mircovili