Chapter 2: Cells

Question 1

What is a light microscope?

Answer 1

-Used in school laboratories
-Light shines through the specimen that is being observed
-Can magnify about 1500x
-Photograph taken using a light microscope is called a photomicrograph

Question 2

What is an electron microscope?

Answer 2

-A picture taken using a light mciroscope is called an electron micrograph
-Beam of electrons to magnify the object 500, 000 times

Question 3

Cell

Answer 3

The smallest units from which all organisms are made

Question 4

Cell Membrane

Answer 4

-Thin layer of protein and fat surrounding the cytoplasm of every cell
-Partially Permeable(allows certain molecules and ions to pass but not others)
-Controls what moves in and out of the cell.
-Seperates the contents of the cell from its environment

Question 5

Cell Wall

Answer 5

-A tough layer mad eof mainly cellulose that are found outside the cell membrane in plant cells.
-are polysaccharides
-Are fully permeable due to large gaps between latticed fibres
-It supports and protects the cell from bursting if it absorbs a lot of water and swells.

Question 6

Cytoplasm

Answer 6

-The jelly-like substance–made mostly from water– that fills most of space in the cell.
-Helps organelles stay in place and movement
-It is a storage space for many substances dissolved in it
-Many metobloic reactiosn like protein synthesis take part in the cytoplasm

Question 7

Vacuole

Answer 7

-The fluid-filled space omsode a cell surrounded by its own membrane.
-Plant cells have large permanent vauoles while Animal cells have small vesicles
-Vacuoles contain solution of sugars. and other substances such as cell sap
-Helps the cell stay structured through water pressure that advances outwards and helps it keep it in shape

Question 8

Nucleus

Answer 8

-A structure containing DNA in the form of chromosomes which are inherited from the organisms parent
-THe information on the DNA determines what kind of proteins are usually made up in the cell

Question 9

Chloroplasts

Answer 9

-Small structures found inside some plant cells in which a green pigment known as Chlorophyll is present.
-The chlorophull absorb energy from sunlight to use the energy to make food for the plant by photosntheseis.
-starch grains

Question 10

Mitochondria

Answer 10

A small structure in the cell where aerobic respirtation takes place to release enrgy from glucose
-The more energy a cell needs the more mitochondria it has

Question 11

Ribosomes

Answer 11

-Tiny structures found in a cell that use information on DNA to make protein molecules.

Question 12

Bacteria

Answer 12

-unicellular organism whose cells do not contain an nucleus

Question 13

Bacterial Cells

Answer 13

-Cell wall not made of cellulose
-partially permeable membrance pressed tightly against cell wall.
-Cytoplasm and ribsomes but no mitochondria or chloroplast
-do not have nucelus
-Prokaryotic cells
-Circle of DNA(bacterial chromosome)
-plasmids(tiny molecules of DNA)

Question 14

Tissue

Answer 14

A collection of similar cells that work together to perform a particulur function

Question 15

Ciliated Cell

Answer 15

-Lining the trachea and bronchi of animals
-Moved mucus upwards

Question 16

Neurone

Answer 16

-In the nervous systems of animals
-conducting electrical impulses

Question 17

Red Blood cell

Answer 17

-In the blood of mammals
-Transports oxygen

Question 18

Sperm Cell

Answer 18

-Produced in the testes of mammals
-The male gamete in sexual reproduction

Question 19

Egg cell

Answer 19

-Produced in the ovaries of mammals
-The female gamete in reproduction

Question 20

root hair cell

Answer 20

near the tips of the roots of flowering plants
-absorption of water and mineral ions

Question 21

palisade mesophyll cell

Answer 21

-in the leaves of flowering plants
-photosynthesis

Question 22

Organs

Answer 22

a group of tissues that work together to perform a particulur function

Question 23

Organ System

Answer 23

several organs that work together to perform a particulur function