topic 3 key terms

Question 1

Bacterial capsule

Answer 1

A polysaccharide layer that surrounds bacterial cells.and provides strength.

Question 2

Cell

Answer 2

The basic unit of a living organism composed of organelles suspended in a cytoplasm with a cell membrane surrounding it.

Question 2

Cell wall

Answer 2

A tough outer layer made of polysaccharides found in plant cells, bacteria and fungi.

Question 2

Centrioles

Answer 2

Structures found in the cytoplasm made of microtubules that produce the spindle fibres during mitosis.

Question 3

Flagella

Answer 3

A whip-like structure found on bacterial cells that is used for cell movement.

Question 4

Golgi apparatus

Answer 4

An organelle found in eukaryotic cells that is involved in the modification and packaging of proteins.

Question 5

Lysosomes

Answer 5

Membrane-bound vesicles found in the cytoplasm that contain a hydrolytic enzyme called lysozyme.

Question 6

Mesosomes

Answer 6

Inward folds in the membrane of bacteria which are used for respiration.

Question 7

Mitochondrion

Answer 7

An organelle found in eukaryotic cells that is the site of aerobic respiration.

Question 8

Nuclear envelope

Answer 8

A double membrane that surrounds the nucleus.

Question 9

Nucleolus

Answer 9

A structure found inside the nucleus that contains proteins and RNA and is involved in synthesizing new ribosomes.

Question 10

Nucleus

Answer 10

An organelle found in eukaryotic cells that stores the genetic information of the cell as chromosomes and is surrounded by a membrane called the nuclear envelope.

Question 11

Pili

Answer 11

Small hair-like projections on the surface of bacterial cells used to adhere to other cells.

Question 12

Plasmid

Answer 12

Loops of DNA found in the cytoplasm of prokaryotic cells.

Question 13

Prokaryotic cell

Answer 13

A type of cell that does not contain any membrane bound
organelles or a nucleus.
cell

Question 14

Ribosomes

Answer 14

Organelles found either free in the cytoplasm or membrane bound that are
involved in the synthesis of proteins.

Question 15

Rough endoplasmic reticulum (RER)

Answer 15

A membrane-bound organelle that is involved in the synthesis and packaging of proteins.

Question 16

Smooth endoplasmic reticulum (SER

Answer 16

A membrane-bound organelle involved in lipid synthesis.

Question 17

Sperm cell

Answer 17

The male gamete which contains a long tail, an acrosome and lots of mitochondria and is specialised to fertilise an egg cell.

Question 18

Acrosome

Answer 18

An organelle found in the head of sperm cells which is specialised to digest the outer coating of an egg cell during fertilisation.

Question 19

Zona pellucida

Answer 19

The tough outer layer of the egg cell which is composed of glycoproteins and is used to prevent multiple sperm cells from fertilising the egg.

Question 20

Locus

Answer 20

The location of a gene on a chromosome

Question 21

Sex linkage

Answer 21

An allele which is found on a sex chromosome and so its expression is determined on the gender of the orgranism.

Question 22

Meiosis

Answer 22

A type of cell division used to produce gametes that produces four genetically different haploid daughter cells from one parent cell.

Question 23

Mitosis

Answer 23

The division of a cell to produce two genetically identical daughter cells.

Question 24

Independent assortment

Answer 24

A source of variation in meiosis where the bivalent chromosomes can line up either way around on the metaphase plate.

Question 25

Asexual reproduction

Answer 25

The production of genetically identtical offspring from one parent through the process of mitosis.

Question 26

Continuous variation

Answer 26

A type of variation within a population produced by polygenic inheritance where the phenotypes are spread over a range of values.

Question 27

Differential gene expression

Answer 27

The process of switching on or off genes to control functions within a cell by varying the production of proteins.

Question 28

DNA methylation

Answer 28

The epigenetic modification of DNA by the addition of a methyl group which reduces transcription.

Question 29

Epigenetics

Answer 29

The study of how gene expression influences traits in an organism.

Question 30

Histone acetylation

Answer 30

The epigenetic modification of histone proteins by the addition of an acetyl group which relaxes the DNA and increases transcription.

Question 31

Lac operon

Answer 31

A group of genes that control lactose uptake and metabolism in certain types of bacteria and are all regulated by the binding of the lac repressor to the lac operator.

Question 32

Operon

Answer 32

A group of genes which are all under the control of the same operator.

Question 33

Organ

Answer 33

A group of specialised tissues working together to carry out a specific function.

Question 34

Organ system

Answer 34

A group of specialised organs working together to carry out a specific function.

Question 35

Pluripotent stem cell

Answer 35

A type of stem cell which has the ability to differentiate into any cell type in the body

Question 36

Polygenic inheritance

Answer 36

The inheritance of multiple different alleles at multiple loci that control a single phenotype

Question 37

Stem cell

Answer 37

An undifferentiated cell that can divide to produce many specialised cells of the same type.

Question 38

Tissue

Answer 38

A group of specialised cells working together to carry out a specific function.

Question 39

Totipotent stem cell

Answer 39

A type of stem cell which has the ability to differentiate into any type of cell in the body or in the placenta.