Biology Topic 1 Definitions

Question 1

Cell membrane

Answer 1

Thin layer around cytoplasm of cell. Controls movement in and out of the cell

Question 2

Cytoplasm

Answer 2

Liquid gel that makes up body of the cell. Where many chemical reactions take place

Question 3

Nucleus

Answer 3

Contains DNA for making new cells and organisms as well as controlling reactions in the cell

Question 4

Organelles

Answer 4

Tiny structures that carry out specific structures

• Nucleus
• Mitochondria

Question 5

DNA

Answer 5

Strands of genes that can react to make proteins if needed

Question 6

Mitochondria

Answer 6

Where cellular respiration takes place. Glucose is broken down using oxygen to create energy.

Question 7

Cell wall

Answer 7

Rigid structure surrounding plant and bacterial cells. Support cell and help keep its shape

Question 8

Vacuole

Answer 8

Space in cytoplasm filled with cell sap, a store of water and nutrients.

Question 9

Chloroplasts

Answer 9

Organelle in PLANT cells containing chlorophyll. Where photosynthesis takes place

Question 10

Chlorophyll

Answer 10

Green substances in chloroplasts that absorbs energy from sunlight

Question 11

Electron microscope

Answer 11

Instrument which magnifies specimens using a beam of electrons

Question 12

Chromosomal DNA

Answer 12

DNA which makes up the chromosomes of a cell

Question 13

Plasmid DNA

Answer 13

Circle of extra DNA only found in bacteria cells

Question 14

Flagella

Answer 14

Whip-like protein found on bacteria cells. Beats back and forward and is used for movement

Question 15

Chromosomes

Answer 15

Thread-like structures found in nucleus of cell to carry the genetic information

Question 16

Genes

Answer 16

Section of DNA which codes for specific proteins

Question 17

Double helix

Answer 17

Structure of DNA

Question 18

Bases

Answer 18

Chemicals that link the two strands in DNA

Question 19

Adenine, thymine, cytosine and guanine

Answer 19

Bases paired up into complementary base pairs linked by weak hydrogen bonds

Question 20

Genome

Answer 20

All genetic information of an organism as a list of every base

Question 21

Genetic engineering

Answer 21

Process of removing a gene from one organism and inserting it into the DNA in a cell of another organism.

Question 22

Genetically modified organisms (GMOs)

Answer 22

Organism that has had a gene from another organism introduced

Question 23

Herbicide

Answer 23

Chemical that kills plants, usually used on weeds

Question 24

Biodiversity

Answer 24

Variety of species in a given area

Question 25

Diploid

Answer 25

Cell that has two sets of chromosomes

Question 26

Mitosis

Answer 26

Division of parent cell to produce two genetically identical diploid cells

Question 27

Gametes

Answer 27

Sex cells produced by male or female reproductive cells. Uses meiosis

Question 28

Haploid

Answer 28

Having one set of chromosomes - gametes

Question 29

Zygote

Answer 29

Fertilised egg cell

Question 30

Meiosis

Answer 30

Division of parent cell to produce two genetically identical haploid cells

Question 31

Light microscope

Answer 31

Instrument which magnifies specimens using light and lenses

Question 32

Thermistor

Answer 32

Component whose resistance gets smaller when it gets hotter

Question 33

Watts

Answer 33

Unit for measuring power. 1 Watt = 1 joule of energy transferred every second