The Cell

Question 1

Define a cell

Answer 1

The smallest unit of matter that can live independently and reproduce itself.

Question 2

What is the study of cells called?

Answer 2

Histology

Question 3

List all structures that could be found within a cell.

Answer 3

Cell membrane
Cytoplasm
Mitochondria
Ribosomes
Endoplasmic reticulum
Smooth endoplasm reticulum
Golgi apparatus
Lysosomes
Centrosomes
Centrioles
Nucleus
Nucleolus
Nucleoplasm
Chromatin
Chromosomes

Question 4

What is cytoplasm and what is its function?

Answer 4

Protoplasm inside the cell but outside of the nucleus
Made from water, inorganic and organic salts, lipids, carbohydrates, nitrogenous substances (amino acids).
Suspends all organelles in cell

Question 5

What is the mitochondria and what is its function?

Answer 5

Power house of cell. Has chemical reactions which produce energy and release ATP for cell to use

Question 6

What are the ribosomes of a cell and what are their function?

Answer 6

Protein factories. Create proteins and enzymes for growth and repair

Question 7

What is rough endoplasmic reticulum and what is its function?

Answer 7

Circulatory system of a cell. Has ribosomes on its surface and processes the proteins made by the ribosomes.

Question 8

What is smooth endoplasmic reticulum and what is its function?

Answer 8

Smooth endoplasmic reticulum is also the cells circulatory system but produces lipids and steroids

Question 9

What is the Golgi apparatus and what is its function?

Answer 9

Main function is to produce lysosomes. GA also transports the proteins from the endoplasmic reticulum into the rest of the cell.

Question 10

What is a lysosome in the cell and what is its function?

Answer 10

Lysosomes are organelles with digestive enzymes in them that destroy old cells as well as break down food to produce and release ATP into the greater cell.

Question 11

What is a centrosome and what is its function?

Answer 11

Centrosomes are dense areas of cytoplasm that hold the centrioles and where spindle fibres form during cell division

Question 12

What is a centriole and what is its function?

Answer 12

Two organelles lying at right angles to one another that are pulled apart and aid cell division in mitosis

Question 13

What is a nucleus and its function?

Answer 13

Largest organelle within the cell. Is the centre that controls growth, repair and reproduction. Has its own set of structures within it.

Question 14

What is the nucleolus and its function?

Answer 14

Small bodies/ organelles. Usually 1-2 within each nucleus and its function is to control ribosome production, sending them out into the greater cell once made.

Question 15

What is chromatin and its function?

Answer 15

Loosely coiled DNA strands which during cell division become tightly coiled and form chromosomes

Question 16

What is nucleoplasm and its function?

Answer 16

Type of protoplasm found only in the nucleus. Suspends the nucleus structures within the nucleus and provides nutrients and chemicals required by these structures.

Question 17

What is a chromosome and its function?

Answer 17

Two chromatids of DNA held together by a centromere. DNA is organised into genes that control activity and inheritance

Question 18

What is the cell membrane and its function?

Answer 18

Semi permeable membrane made of lipids and proteins. 2 functions; to keep organelles in and let fats/proteins etc out

Question 19

What are the 5 ways substances can enter or leave a cell?

Answer 19

Diffusion
Osmosis
Dissolution
Active transport
Filtration

Question 20

What is diffusion?

Answer 20

When a substance moves from high/strong concentration/pressure solution to a low/weak concentration/ pressure solution until both solutions equal/balanced

Question 21

What is osmosis?

Answer 21

When water molecules move from a high concentration solution to a low concentration solution due to osmotic pressure. When balance occurs, isotonic pressure is achieved.

Question 22

What is dissolution?

Answer 22

Substance dissolves through the phospholipid membrane into the cell where it then dissolves further in the cytoplasm.

Question 23

What is active transport?

Answer 23

When a substance is too big or doesn’t dissolve in fat, it is carried by a carrier substance across the cell membrane. Energy is required for this form of movement.

Question 24

What is filtration?

Answer 24

When water and substances push on the cell membrane changing the pressure and forcing movement across the membrane.

Question 25

What is the function of a cell and how can it be remembered?

Answer 25

Function changes depending on type of cell. Way to remember all functions is MRS GREM

Question 26

Explain the acronym MRS GREM to remember the functions of a cell.

Answer 26

M - movement R - respiration S - sensitivity G - growth R - reproduction E - excretion M - metabolism

Question 27

Define anabolism.

Answer 27

Chemical reaction within a cell to create new products for growth and repair ie proteins

Question 28

Define catabolism.

Answer 28

Chemical reaction which breaks a substance down into its simplest form eg CO2 or ATP.

Question 29

How does a cell turn into a functioning human body?

Answer 29

Cells of the same function make tissue Tissue of the same function make organs Organs of a similar function make systems Systems working cohesively in one body creates an organism

Question 30

What are the two types of reproduction certain cells can undergo?

Answer 30

Mitosis - genetically identical Meiosis - genetically variable

Question 31

What are the 4 (or 5) stages of mitosis?

Answer 31

Prophase, metaphase, anaphase and telophase (interphase if counted).

Question 32

What occurs in the prophase stage of mitosis?

Answer 32

Centrosome splits in half, also splitting the centrioles apart. Now held together by spindle fibres Chromatids condense to form chromosomes Nucleolus disappears

Question 33

What occurs in the metaphase stage of mitosis?

Answer 33

Centrioles move to opposite poles of cell Chromosomes are attached to centrioles by spindle fibres, arrange themselves in centre of the cell and start being pulled apart into separate chromatids by centrioles Nuclear membrane disappears

Question 34

What occurs in the anaphase stage of mitosis?

Answer 34

Cell membrane dimples starting to create two separate cells Chromatids pulled further apart creating identical halves of pairs pulled to opposite side of cell Spindle fibres start to make new centromeres

Question 35

What occurs in the telophase stage of mitosis?

Answer 35

Spindle fibres disintegrate and centrioles replicate Nuclear membrane forms around chromatids Cell membrane continues to constrict until two daughter cells are created, identical to parent cell

Question 36

What occurs in the interphase stage of mitosis?

Answer 36

First stage before prophase. Where the cell begins to prepare for cell division. The cell grows bigger and DNA chromatin is doubled.

Question 37

What happens in meiosis?

Answer 37

Reproduction of sex cells resulting in a gamete Chromosomes are not pulled apart at the centromere, meaning full chromosomes move to pole ends of the dividing cell This means half the number of chromosomes enter into each new cell A zygote is created when a sperm fuses with an ovum to recreate the full 46 chromosomes a cell should have The zygote then divides by mitosis to form an embryo