Cells

Question 1

Function: cell membrane

Answer 1

Controls what enters and leave the cell

Question 2

Function: nucleus

Answer 2

Control centre of the cell - control is mediated by DNA

Question 3

Function: nucleolous

Answer 3

Manufactures ribosomes

Question 4

Function: mitochondrion

Answer 4

Site of aerobic respiration

Question 5

Function: smooth ER

Answer 5

Manufactures steroids and cholesterol

Question 6

Function: Rough ER

Answer 6

Site of protein synthesis

Question 7

Function: Golgi apparatus

Answer 7

Sorts, packages and modifies proteins for export

Question 8

Function: lysozyme

Answer 8

Contains enzymes for intracellular digestion

Question 9

Function: ribosome

Answer 9

Site of translation

Question 10

What does a tight junction do?

Answer 10

• intimate association between membranes of adjacent cells

- prevents substances from passing between cells and forces them to pass through cell membrane

Question 11

What do desmosomes do?

Answer 11

• strong and large contact point between two cells)

- intermediate filaments provide strength

Question 12

What do gap junctions do?

Answer 12

• channels connecting cytoplasm of two cells made up of proteins called connexons
• allow ions and small molecules to pass between adjacent cellls

Question 13

What are the different types of cell junctions?

Answer 13

• tight junctions
• desmosomes
• gap junctions

Question 14

What are the stages of the cell cycle?

Answer 14

• G1 (first gap phase)
• S phase (synthesis)
• G2 phase
• M (mitotic) phase

Question 15

What is G0 phase?

Answer 15

When a cell leaves the cell cycle and ceases to divide for days, years of the rest of its life

Question 16

What occurs during G1 phase?

Answer 16

Growth and normal metabolic roles

Question 17

What occurs during S phase?

Answer 17

DNA replication

Question 18

What occurs during G2 phase?

Answer 18

Growth and preparation for mitosis.

Question 19

What are the main functions of mitosis?

Answer 19

Growth and regeneration/repair of body tissues

Question 20

What occurs during prophase?

Answer 20

• chromosomes condense
• nuclear envelope breaks down
• spindle fibres grow from centrioles
• centrioles migrate to opposite poles of the cell

Question 21

What occurs during metaphase?

Answer 21

• chromosomes lie along cell midline
• some spindle fibres attach to kinetochores
• fibres of aster attach to plasma membrane

Question 22

What occurs during anaphase?

Answer 22

• centromeres divide into two
• spindle fibres pull sister chromatids to opposite poles
• each pole now has an identical set of genes

Question 23

What occurs during telophase?

Answer 23

• chromosomes gather at each pole of the cell
• chromatin decondenses
• new nuclear envelope appears at each pole
• new nucleoli forms in each nuclei
• mitotic spindle breaks down
• cytokinesis occurs and the cytoplasm splits into two

Question 24

Function: centriole

Answer 24

Forms spindle during cell division

Question 25

What occurs during G2 phase?

Answer 25

- DNA checked for errors | - cell grows and produces organelles for mitosis

Question 26

What is the diameter of a mitochondrion?

Answer 26

0.5-1.0 micrometers

Question 27

What make up the cytoskeleton?

Answer 27

Proteins that have a structural role within the cell

Question 28

What are the types of proteins that make up the cytoskeleton?

Answer 28

- microfilaments - intermediate filaments - microtubules

Question 29

Microfilaments

Answer 29

- thinnest - made of actin - 2nm wide - outer shell of the cell - gives peripheral support to the cell, pinches cell during cytokinesis

Question 30

Intermediate filaments

Answer 30

- 10nm wide - form networks that can transverse the cell - particularly important for cell junctions

Question 31

Mircotubules

Answer 31

- important for transport - made of tubulin - are a part of the spindle in mitosis - 25nm wide

Question 32

How long are each phases of the cell cycle?

Answer 32

8-10 6-8 4-6 1-3

Question 33

Microvilli

Answer 33

- increase the surface area of a cell - commonly involved in absorption - microfilaments for rigidity - 90nm in diameter

Question 34

Cilia

Answer 34

- used for moving material along cell membrane - microtubules for strength (9 pairs) - attached to a basal body inside the cell - 250nm in diameter

Question 35

What are spindle fibres made of?

Answer 35

Microtubules