Organisation of the Organism.

Question 1

Where is cytoplasm found and what does it contain?

Answer 1

Cytoplasm is found inside the cell and contains all the other cell structures.

Question 2

What are the three functions of cytoplasm?

Answer 2

• supports organelles.
• site of many chemical reactions.
• contains water and many solutes.

Question 3

What is the large nucleus surrounded by?

Answer 3

The large nucleus is surrounded by a nuclear membrane to separate it from the cytoplasm.

Question 4

What are the three functions of the large nucleus?

Answer 4

• controls cell division.
• contains genetic material in chromosomes which control how cells grow and work.
• controls cell activities.

Question 5

What does the cell membrane surround?

Answer 5

The cell membrane surrounds the cytoplasm.

Question 6

What is the cell wall made of and what does it surround in plant cells?

Answer 6

The cell wall is made of cellulose and surrounds the cell membrane in plant cells.

Question 7

What are the 4 functions of the cell wall?

Answer 7

• gives the cell extra support and defines its shape.
• protects the cell.
• it prevents the cell from bursting when it absorbs water by osmosis.
• it is fully permeable to water and dissolved substances.

Question 8

What are chloroplasts?

Answer 8

Chloroplasts are organelles found in the cytoplasm that are packed with the pigment chlorophyll and so are green in color.

Question 9

What are the 3 functions of chlorophyll?

Answer 9

• site of photosynthesis, providing food for plants.
• the chlorophyll pigments absorb light energy and enzymes used to make glucose by photosynthesis.
• stores starch.

Question 10

What are vacuoles?

Answer 10

Vacuoles are large vesicles that take up a large part of the interior of plant cells.

Question 11

What are the 3 functions of the vacuole?

Answer 11

• contains cell sap to provide turgor pressure which maintains the shape and firmness of the cell.
• used for storage of certain materials.
• also helps support the shape of the cell.

Question 12

What cells are mitochondria not found in?

Answer 12

prokaryotes/bacteria.

Question 13

What are mitochondria?

Answer 13

Mitochondria (singular: mitochondrion) are organelles found throughout the cytoplasm and they also contain a small quantity of DNA.

Question 14

What are the 2 functions of mitochondria?

Answer 14

• site of aerobic respiration, providing energy for the cell.
• cells with high rates of metabolism will have significantly higher numbers of mitochondria than cells with lower numbers of reactions taking place in them.

Question 15

What are ribosomes?

Answer 15

Ribosomes are tiny structures that can be free within the cytoplasm or attached to a system of membranes within the cell.

Question 16

What is the function of ribosomes?

Answer 16

• site of protein production in protein synthesis.

Question 17

What are specialized cells and how are these differences controlled?

Answer 17

Specialized cells are those which have developed certain characteristics in order to perform particular functions. These differences are controlled by genes in the nucleus.

Question 18

Cells specialize by undergoing differentiation: Define differentiation.

Answer 18

This is a process by which cells develop the structure and characteristics needed to be able to carry out their functions.

Question 19

What is the function of the ciliated cell?

Answer 19

movement of mucus in the trachea and bronchi.

Question 20

What is the adaptation of a ciliated cell?

Answer 20

Cilia beat to move mucus and trapped particles in the trachea and bronchi.
Cilia are also found in the oviducts and they move the egg from the ovary to the uterus.

Question 21

Where are neurons found?

Answer 21

Found in the nervous system - brain, spinal cord and nerves.

Question 22

What does dendrite do?

Answer 22

Dendrite collects information from other cells.

Question 23

Why is the axon covered with a fatty sheath?

Answer 23

The axon is covered with a fatty sheath, which insulates the nerve cell and speeds up the nerve impulse.

Question 24

What is the name of the red pigment in red blood cells and what does it do?

Answer 24

Red blood cells contain the red pigment hemoglobin which transports oxygen.

Question 25

Why does the neuron cell have extensions and branches?

Answer 25

• The cell has extensions and branches so that it can communicate with other nerves cells, muscles, and glands.

Question 26

Why are neuron cells long?

Answer 26

• long so that neves can run to and from different parts of the body to the central nervous system.

Question 27

What is the benefit of the biconcave disc shape of a red blood cell?

Answer 27

• biconcave disc shape increases surface area for more efficient diffusion of oxygen.

Question 28

Why do red blood cells contain no nucleus?

Answer 28

• contains no nucleus to increase the amount of space available for hemoglobin inside the cell.

Question 29

What does the head of a sperm cell contain?

Answer 29

the head contains the genetic material for fertilization in a nucleus.

Question 30

What is the middle section of the sperm cell packed with?

Answer 30

The middle section is packed with mitochondria to release the energy needed to swim and fertilize the egg.

Question 31

What does the tail of the sperm enable it to do?

Answer 31

The tail enables the sperm to swim.

Question 32

What does the ovum contain a lot of?

Answer 32

Contains a lot of cytoplasm which has nutrients for the growth of the early embryo.

Question 33

Where are sperm cells and egg cells (ova) made?

Answer 33

Sperm cells are made in the testes and egg cells are made in the ovaries.

Question 34

What is the function of the following:

• nerve cells.
• red blood cells.
• sperm and egg cells.

Answer 34

• nerve cells = conduction of impulses.
• red blood cells = transport of oxygen.
• sperm and egg cells = reproduction.

Question 35

What does the root hair cell increase?

Answer 35

Root hair cells increase the surface area of a cell to ensure maximum absorption of water and mineral ions.

Question 36

Why are the walls of a root hair cell thin?

Answer 36

Walls are thin to ensure water moves through quickly.

Question 37

How are the cells of xylem vessels joined?

Answer 37

The cells of xylem vessels are joined end to end with no cross walls to form a long continuous tube.

Question 38

Why are the cells of xylem vessels dead?

Answer 38

Cells are dead without organelles or cytoplasm to allow free passage of water.

Question 39

How do the walls of xylem vessels become thickened?

Answer 39

Their walls become thickened with a substance called lignin which means they are able to help support the plant.

Question 40

What does the palisade mesophyll cell contain many of?

Answer 40

Contain many chloroplasts for maximum photosynthesis.

Question 41

What is the function of the following:

• root hair cells.
• xylem vessels.
• palisade mesophyll cell.

Answer 41

• root hair cells = absorption of mineral ions and water from the soil.
• xylem vessels = conduction of water through the plant; support of the plant.
• palisade mesophyll cell = photosynthesis.

Question 42

What is the function of the following:

• epidermis.
• palisade and spongy mesophyll.
• vascular tissue.

Answer 42

• epidermis = protects against water loss, and may be involved in the absorption of water and ions.
• palisade and spongy mesophyll= photosynthesis.
• vascular tissue = transports materials through the plant body.

Question 43

What is the function of the following:

• epithelium.
• blood.
• muscle tissue.

Answer 43

• epithelium = lines tubes such as the gut and covers surfaces such as the skin.
• blood = transports substances around the body, and defends against disease.
• muscle tissue = muscles contract.

Question 44

Diagrams and practice calculations:
Magnification.
Image Size.
Actual Size.
Red blood cell.
Sperm and egg cells.
Ciliated cells.
Neurons.
Xylem vessels.
Palisade mesophyll cells.
Root hair cells.
Animal cells.
Plant cell.
Prokaryote cell.

Answer 44

Magnification.
Image Size.
Actual Size.
Red blood cell.
Sperm and egg cells.
Ciliated cells.
Neurons.
Xylem vessels.
Palisade mesophyll cells.
Root hair cells.
Animal cells.
Plant cell.
Prokaryote cell.