Characteristics of cells

Question 1

Cell Theory

Answer 1

The cell theory states that:
All living things are made of one or more cells
Cells are the basic unit of life
Cells come only from other cells

Question 2

Common parts of a cell

Answer 2

Cell membrane
Ribosome
DNA
Cytoskeleton
Cytoplasm

Question 3

Cell membrane

Answer 3

The cell membrane, also called the plasma membrane is a thin coat of lipids that surrounds a cell. It forms the physical boundary between the cell and its environment, so you can think of it as the skin of the cell.

Question 4

Cytoplasm

Answer 4

Cytoplasm refers to all of the cellular material inside the cell membrane other than the nucleus. Cytoplasm is made up of a watery substance called cytosol and contains other cell structures such as ribosomes.

Question 5

Ribosomes

Answer 5

Ribosomes are structures in the cytoplasm where proteins are made.

Question 6

Cytoskeleton

Answer 6

The cytoskeleton consists of filaments and tubules that crisscross the cytoplasm and help maintain the cell’s shape.

Question 7

DNA

Answer 7

DNA is a nucleic acid found in cells. It contains genetic instructions that cells need to make proteins.

Question 8

Animal Cells features AC

Answer 8

Animal cell features often relate to heterotrophic nutrition and high rates of metabolic activity.

The absence of the cellulose wall means that animal cells may be very irregular in shape.

The amount of cytoplasm that can be controlled by the nucleus is limited, so that animal cells may be quite small- about 25 µm in diameter.

Question 9

Secretory vesicles AC

Answer 9

containing cell products such as hormones or enzymes are much more common in animal cells

Question 10

Cytoplasm AC

Answer 10

Cytoplasm of animal cells is often denser, with many more organelles and dissolved substances.

Question 11

Vacuoles AC

Answer 11

Vacuoles are small and temporary. They can be involved with digestion or with excretion

Question 12

Glycogen AC

Answer 12

Glycogen is the storage form of carbohydrates

Question 13

Plant and animal cells common features APC

Answer 13

Plant and animal cells have common features which relate to maintaining the characteristics of life.

Question 14

Cell surface membrane APC

Answer 14

Cell surface membrane which surround the cytoplasm. It controls the entry and exit of dissolved substances and separates the cell’s contents from its surroundings.

Question 15

Cytoplasm APC

Answer 15

Cytoplasm contains water and dissolved substances such as sugar and salts. Chemical reactions go down in organelles, for example, proteins are made in ribosomes on rough endoplasmic reticulum and the energy is released by respiration in mitochondria in a cell indicate a high rate of metabolism.

Question 16

Nucleus APC

Answer 16

Nucleus contains the genetic material (DNA which makes up genes on the chromosomes). This carries the coded instructions for controlling the activities and characteristics of the cell. The chromosomes only become visible during cell division.

Question 17

Plant cell features PC

Answer 17

Plant cell features often relate to autotrophic nutrition.

The presence of the cellulose cell wall means that plant cells tend to be regular in shape.

The presence of vacuole means that plant cells may be quite large- often 60 µm in diameter.

Question 18

Chloroplasts PC

Answer 18

Chloroplasts contain the pigment chlorophyll for light absorption and the enzymes necessary for the production of glucose by photosynthesis.

Question 19

Large permanent vacuole PC

Answer 19

Large permanent vacuole contains water necessary to provide turgor pressure may store ions and molecules.

Question 20

Starch PC

Answer 20

Starch in the cytoplasm or the chloroplasts is the storage form of carbohydrates.

Question 21

Cellulose cell wall PC

Answer 21

Cellulose cell wall provides structural support and protects against damage cause by osmotic intake of water. The cell wall is freely permeable to water and dissolved substances.

Question 22

The features of plants and animal cells

Answer 22

The features of plant and animal cells allow these cells to carry out the basic processes of life. The differences between the plant and animal cells are due to the differences in lifestyle between animals and plants, especially due to their different methods of nutrition.

Question 23

The 4 basic characteristics of all cells

Answer 23

The 4 basic characteristics of all cells:
A boundary between the inside and outside
Instructions for the cell to build and maintain itself
Machinery to execute the instructions
A means to convert energy into useful forms