Topic 2 - Cell Structure

Question 1

What is a eukaryotic cell?

Answer 1

Holly organised structures that contain a nucleus and membrane bound organelles allowing them to perform specialised functions.

Question 2

What is the nucleus structure?

Answer 2

Surrounded by a double membrane with nuclear pores, allowing molecules to move in and out.
Chromatin: DNA and associated proteins.
Nucleolus: produces ribosomes
Nucleoplasm: jellylike substance that forms the bulk of the nucleus

Question 3

What is the structure of the rough endoplasmic reticulum?

Answer 3

A network of flattened sacs enclosed by a membrane. Surface is studied with ribosomes.

Question 4

What is the function of the rough endoplasmic reticulum?

Answer 4

Folds and processes, proteins synthesised by the ribosomes

Question 5

What is the structure of the smooth endoplasmic reticulum?

Answer 5

A network of membrane bound sacs without ribosomes.

Question 6

What is the function of the smooth endoplasmic reticulum?

Answer 6

Synthesis and processes, lipids.

Question 7

What is the structure of the Golgi apparatus?

Answer 7

A stack of fluid filled flattened sacs with vesicles at the edges.

Question 8

What is the function of the Golgi apparatus?

Answer 8

• Modifies packages and transport proteins and lipids.
• Produces lysosomes.

Question 9

What is the structure of ribosomes?

Answer 9

Made of two sub units and found either free in the cytoplasm or attached to the rough endoplasmic reticulum.

Question 10

What is the function of the ribosomes?

Answer 10

Site of protein synthesis.

Question 11

What is the structure of the mitochondria?

Answer 11

Oval shaped surrounded by a double membrane.
The inner membrane is folded into cristae which increases the surface area for respiration.
The internal space called the matrix contains enzymes needed for aerobic respiration to produce ATP .

Question 12

What is the structure of lysosomes?

Answer 12

Small vesicles bound by a single membrane containing digestive enzymes.

Question 13

What is the function of lysosomes?

Answer 13

Breakdown waste materials, old organelles and pathogens.

Question 14

What is the structure of a centriole?

Answer 14

Hollow cylinders made of microtubules arranged at right angles to each other.

Question 15

What is the function of centrioles?

Answer 15

Organise the spindle fibres during cell division.

Question 16

What is cell specialisation?

Answer 16

The process by which cells develop specific structures and functions to perform particular roles within an organism.

Question 17

Compare the shape size and organelle adaptions of muscle cells and red blood cells.

Answer 17

Muscle cells contain many mitochondria to provide energy for contraction while red blood cells are specialised for carrying oxygen due to their lack of nucleus and presents of haemoglobin.

Question 18

What is cell differentiation?

Answer 18

The process to which unspecialised cells become specialised.

Question 19

How does differentiation work in terms of genes?

Answer 19

Certain genes are activated or deactivated, allowing the cell to produce specific proteins required for its function.

Question 20

What is the function of a nerve cell and how is a nerve cell adapted to its function?

Answer 20

Function: transmit electrical signals throughout the body.
Adaptions: it has a long axon to carry impulses it has a myelin sheath which insulates the axon speeding up electrical transmission and finally many dendrites to connect with other neurons.

Question 21

What is the function of an epithelial cell and how is it adapted to its function?

Answer 21

Function: forms of protective layers or aids absorption
Adaptions: cells in the intestine have microvilli which increase surface area for nutrient absorption and some have cilia to remove mucus in the respiratory tract.

Question 22

What is the function of a sperm cell and how is it adapted to its function?

Answer 22

Function: fertilise an egg.
Adaptions: flagellum mobility, many mitochondria to provide energy for swimming and an acrosome contains enzymes to penetrate the cell membrane.

Question 23

What is the relationship between cells tissues organs and organ systems?

Answer 23

Specialised cells group together to form tissues, tissues combined to form organs and organs work together to form organs systems.

Question 24

What is a cell?

Answer 24

The basic unit of life and is specialised to perform specific functions.

Question 25

What is a tissue and give an example?

Answer 25

Groups of similar cells working together to perform a particular function. Example: muscle tissue contract for movement while epithelial tissue line surfaces.

Question 26

What is an organ and give an example?

Answer 26

Structures made of several tissues that work together to perform complex functions. Example: the heart pumps blood using muscle, tissue, nerve tissue and connective tissue.

Question 27

Give an example and explain what is an organ system?

Answer 27

Groups of organs that work together to carry out vital processes. Example: the digestive system includes organs like the stomach and intestines to breakdown and absorb food.

Question 28

What is a prokaryotic cell?

Answer 28

Simple cells that lack a true nucleus and membrane bound organelles. They are smaller than nucleic cells and have structural adaptions for their specific roles such as a bacteria cell.

Question 29

What are the seven features of a prokaryotic cell?

Answer 29

Cell wall Capsule Plasmid Flagellum Pili Ribosomes Mesosomes

Question 30

What is the function of the cell wall in a prokaryotic cell?

Answer 30

Provides structural support and protection against osmotic pressure.

Question 31

What is the function of the capsule in a prokaryotic cell?

Answer 31

A protective slimy layer outside the cell wall helps to retain moisture and adhere to surfaces. It offers protection against the immune response of host organisms.

Question 32

What is the function of a plasmid or circular DNA in a prokaryotic cell?

Answer 32

Contains genes for survival traits such as antibiotic resistance.

Question 33

What is the pili in a prokaryotic cell?

Answer 33

Thin hair like projections on the surface of the cell and I used to attach to other bacteria cells or surfaces.

Question 34

What is the function of a mesosome?

Answer 34

Contains enzymes required for aerobic respiration and increases surface area for metabolic reactions.

Question 35

What is the constitution of a virus?

Answer 35

Nonliving structures. Made of: nucleic acid as genetic material a protective coat called the acid and some viruses are surrounded by a lipid layer known as the envelope.

Question 36

Compare prokaryotic and eukaryotic cells

Answer 36

Small - larger No true nucleus - nucleus enclosed by envelope Single/circular DNA - linear DNA associated with histones No membrane bound organelles - membrane bound organelles 70s ribosomes - 80s ribosomes Binary fission - mitosis and meiosis Contains plasma - doesn’t contain plasma

Question 37

How do viruses replicate?

Answer 37

They can only replicate in a wholesale they inject them material into the host cell hijacking the hosts machinery to replicate and assembled new virus.

Question 38

What are the five differences between viruses and bacteria?

Answer 38

Non-cellular particles - prokaryotic cells Can be DNA or RNA single or double stranded - circular strand of DNA Replicate inside a host cell - divide by binary fission Smaller - larger Require a host cell to live - can survive and multiply without a host cell.