Chapter 1 - Cells And More Cells

Question 1

Who discovered cells?

Answer 1

Robert Hooke in 1665

Question 2

The cell theory

Answer 2

1. All living organisms are made of one or more cell
2. The cell is the basic organizational unit of life
3. All cells come from pre-existing cells

Question 3

What are proteins for

Answer 3

Essential nutrients for growth and repair of body tissues

Question 4

Cell membrane

Answer 4

Separates inside of cell from outside, controls flow of materials

Question 5

Mitochondria

Answer 5

Where energy is released from glucose to fuel cell activities

Question 6

Ribosomes

Answer 6

Help produce proteins, some float in cytoplasm, others are attached to endoplasmic reticulum

Question 7

Endoplasmic reticulum

Answer 7

Network of membrane covered channels that transport materials made in cell, connected to nucleus

Question 8

Vesicles

Answer 8

Membrane covered sacs transport/store materials inside cell, sometimes help materials enter/exit cell

Question 9

Golgi body

Answer 9

Sorts/packages proteins and other molecules for transport out of cells

Question 10

Vacuoles

Answer 10

Contain water and other materials, used to store/transport small molecules

Question 11

Cytoskeleton

Answer 11

Filaments and tubules provide framework for cell, maintain structure, lay tracks for vesicles and organelles to move along

Question 12

Cell wall

Answer 12

Tough, rigid structure lying outside cell membrane providing structure for cell

Question 13

Chloroplasts

Answer 13

Trap energy from sun to make glucose, broken down in mitochondria

Question 14

Differences in plants and animal cells

Answer 14

1) Plants have 1 large vacuole, animals have several smaller
2) plants have a cell wall
3) plants have chloroplasts

Question 15

Why do we breathe oxygen

Answer 15

Cellular respiration requires oxygen to break down glucose molecules to release energy

Question 16

What are chromosomes

Answer 16

Chromosomes are made up of DNA, master set of instructions determines what cell becomes, how it functions, how long it lives.

Question 17

What can a mutation do

Answer 17

Mutation in a gene can alter structure of protein produced, affects how well the protein does its job

Question 18

Examples of mutagens

Answer 18

Electromagnetic radiation (x rays, UV rays), Mercury

Question 19

How can mutations help

Answer 19

May help organism adapt to environment (eg. Bacteria resisting antibiotics)

Question 20

Three reasons cells divide

Answer 20

1. To repair lost or damaged cells
2. So an organism can grow
3. Reproduction

Question 21

Why do all genes need to be replicated

Answer 21

Genes determine what proteins are produced, every cell needs to have all of the genes required to make proteins

Question 22

What happens during DNA replication

Answer 22

Each chromosome is duplicated, the two copies (sister chromatids) remain attached. If errors occur, usually detected by special proteins. Centrosome also doubles, they help to organize tubules that will make up cytoskeleton

Question 23

What are chromosomes normally like

Answer 23

Very long loose threads, then chromosomes take on thick bulging look just before ready to divide

Question 24

What happens during prophase

Answer 24

Replicated chromosomes condense, membrane of nucleus breaks down, nucleolus, centrosomes head towards opposite ends, spindle fibres begin to form and extend towards centromeres and away from centrosomes

Question 25

What happens during metaphase

Answer 25

Longest phase, centrosomes reach opposite ends, chromosomes line up in middle, spindle fibres stretch from centrosomes to each end of centromeres, become attached

Question 26

What happens during anaphase

Answer 26

Proteins holding chromatids together break apart, spindle fibres retract, pulling a chromatid toward one end of cell (each is now chromosome)

Question 27

What happens during telophase

Answer 27

Spindle fibres disappear, nuclear membrane forms, one at each daughter nuclei, nucleolus appears in each nuclei, chromosomes uncoil

Question 28

What happens during cytokinesis

Answer 28

Ring of specialized proteins around middle of cell contracts, pinches cell membrane until it has divided in two