Cells

Question 1

What is a cell?

Answer 1

the functional basic unit of life.

It is the smallest unit of life that is classified as a living thing, and is often called the building block of life.

Question 2

What does unicellular mean?

Answer 2

consisting of one single cell.

Question 3

What does multicellular mean?

Answer 3

consisting of more than one cell.

Question 4

How many cells does a human usually have?

Answer 4

about 100 trillion or 10^14 cells;

Question 5

What are the two types of cells?

Answer 5

prokaryote and eukaryote

Question 6

Describe prokaryote cells:

Answer 6

usually independent,

simpler, and therefore smaller, than a eukaryote cell, lacking a nucleus and most of the other organelles of eukaryotes.

There are two kinds of these cells: bacteria and archaea; these share a similar structure

Question 7

Describe eukaryote cells:

Answer 7

often found in multicellular organisms.

15 times wider than a typical prokaryote and can be as much as 1000 times greater in volume.

contain membrane-bound compartments in which specific metabolic activities take place.

Question 8

Why do plants have large vacuoles

Answer 8

to store water and help it stay upright

Question 9

Typical Cellular Organelles (structures living in a cell)

Answer 9

– Cell membrane
– Cell wall
– Mitochondrion
– Nucleus
– Chloroplast
– vacuole

Question 10

The mitochondrion is:

Answer 10

Known as the power house of the cell as it is responsible for the production of energy thru cellular respiration. It is enclosed by a thin membranous sac with inner partitions known as cristae

Question 11

Cell Membrane

Answer 11

controls the passage of cellular material in and out of the cell with the use of a double layer of fat and protein which acts as selectively permeable barrier (allows liquids and gases to pass through)

Question 12

Cell wall

Answer 12

Made up of the complex carbohydrate cellulose which helps to protect the cell and offer structural support. Found only in plant cells

Question 13

Nucleus

Answer 13

The “brain” of the cell. Controls cellular activity as it stores the organisms hereditary information on densely. packed genetic material made up of DNA and protein called chromatin. Directs protein synthesis

Question 14

Chloroplast

Answer 14

Found in plant cells only and is responsible for the plants autotrophic qualities. Contains the green pigment chlorophyll which harnesses the energy from sunlight and uses it to power photosynthesis

Question 15

Vacuoles

Answer 15

essentially enclosed compartments filled with water containing inorganic and organic molecules including enzymes in solution.
Formed by the fusion of multiple membrane vesicles and are effectively just larger forms of these. The organelle has no basic shape or size, its structure varies according to the needs of the cell.

Help in Isolating materials that might be harmful or a threat to the cell and in cellular waste management. In plants they are large and few while in animals they are small and numerous

Question 16

Endoplasmic Reticulum

Answer 16

The endoplasmic reticulum (ER) is an eukaryotic organelle that forms an interconnected network of tubules, vesicles, and cisternae within cells.

Rough endoplasmic reticulums synthesize proteins, while smooth endoplasmic reticulums synthesize lipids and steroids, metabolize carbohydrates and steroids, and regulate calcium concentration, drug detoxification, and attachment of receptors on cell membrane proteins.

Question 17

Golgi Apparatus

Answer 17

The primary function of the Golgi apparatus is to process
and package macromolecules, such as proteins and lipids, after their synthesis and before they make their way to their destination; it is particularly important in the processing of proteins for secretion. The Golgi apparatus forms a part of the cellular endomembrane system.

Question 18

Differences between Animal and Plant Cells

Answer 18

Animal Cells - Plant Cells
Usually smaller - Usually larger

No cell wall - A cell wall made of cellulose

Cytoplasm denser and more granular - Cytoplasm not so dense

Cytoplasm fills almost entire cell - only a thin lining of. cytoplasm

Vacuoles are small and temporary - Vacuoles prominent, one or more

Do not contain plastids - Usually contain plastids

Centrosome is present - Centrosome is not present

Question 19

Cell Specialisation

Answer 19

The primary function of the Golgi apparatus is to process and package macromolecules, such as proteins and lipids, after their synthesis and before they make their way to their destination; it is particularly important in the processing of proteins for secretion.

The Golgi apparatus forms a part of the cellular endomembrane system.

Question 20

Red Blood Cells

Answer 20

Red blood cells biconcave disc-like shape affords it increase surface area which results in increase oxygen carrying capacity. The opposite is observed with sickled cell on the left. Patients can become anaemic and suffer from shortness of breath due to the decreased oxygen carrying capacity of each cell.

Question 21

Nerve Cell

Answer 21

Nerve cell functions to receive, conduct and. transmit electrical impulses. The out-reaching dendrites enable maximum interaction with surrounding neurons. The thin myelinated axons allow for accurate transmissions.

Question 22

Diffusion

Answer 22

a process of passive transport in which molecules move from an area of higher concentration to one of lower concentration

Question 23

Osmosis

Answer 23

the movement of water across a membrane from an area of low solute concentration to an area of high solute concentration passing through a selectively permeable membrane

Question 24

Hypertonic Solution

Answer 24

solution has a higher solute (dissolved substance) concentration than the cell does.

has a lower concentration of water than the cell does.

Cell membranes and plant cell
walls are semipermeable barriers, which
means that certain molecules can diffuse
through them, while other molecules can
not.

Question 25

Hypotonic Solution

Answer 25

has a lower solute concentration than the cell does. As a result, it also has a higher concentration of water than the cell does.

Osmosis draws water out of the solution and
into the cells. As a result, plant and animal cells
both appear more plump when placed in a
hypotonic solution.

Question 26

Isotonic Solution

Answer 26

has the same solute concentration,
and thus the same water concentration, as the
cells do.

there would not be a concentration gradient
since a gradient by definition involves a
difference.