Inheritance

Question 1

What is a chromosome?

Answer 1

Thread-like structure found in nucleus and made of DNA

Question 2

What’s DNA?

Answer 2

Double-helix molecule

Question 3

What’s a gene?

Answer 3

A section of DNA that codes (contains information for making a protein)

Question 4

What are somatic chromosomes?

Answer 4

Chromosomes that aren’t sex chromosomes

Question 5

What is a protein?

Answer 5

A chain of amino acids

Question 6

What are sex chromosomes?

Answer 6

Chromosomes that determine gender

Question 7

What are homologous chromosomes?

Answer 7

Chromosomes that carry the same genes and form a pair

Question 8

What is the result of mitosis?

Answer 8

Two genetically identical cells

Question 9

What is the purpose of mitosis?

Answer 9

Growth and repair

Question 10

What is meiosis?

Answer 10

A special type of cell division by which gametes (sex cells) are made

Question 11

What does diploid mean?

Answer 11

2 sets of chromosomes

Question 12

What does haploid mean?

Answer 12

1 set of chromosomes

Question 13

What is the result of meiosis?

Answer 13

Four genetically different haploid cells (with only 23 chromosomes)

Question 14

Where does meiosis take place?

Answer 14

In testes and ovaries

Question 15

How many cells are produced in mitosis and meiosis?

Answer 15

• Mitosis - 2

* Meiosis - 4

Question 16

What is variation?

Answer 16

Small differences between members of the same species

Question 17

What is genetic variation?

Answer 17

Differences caused by genes inherited from parents

Question 18

What is environmental variation?

Answer 18

Differences caused by the environment

Question 19

What is an allele?

Answer 19

A version of a gene

Question 20

What is a dominant allele?

Answer 20

Only 1 copy is necessary for characteristic to be shown

Question 21

What is a recessive allele?

Answer 21

2 recessive alleles are needed (no dominant allele present) for characteristics to be shown

Question 22

What is the genotype?

Answer 22

The genetic makeup, i.e. which alleles are present

Question 23

What does homozygous mean?

Answer 23

Having 2 identical alleles

Question 24

What does heterozygous mean?

Answer 24

Having 2 different alleles

Question 25

What is the phenotype?

Answer 25

The characteristic that is shown

Question 26

What does co-dominance mean?

Answer 26

Both alleles contribute to the phenotype, so that both characteristics are present at the same time

Question 27

What is a carrier?

Answer 27

When someone has one recessive allele but doesn't show the phenotype

Question 28

What are mutations?

Answer 28

Changes in the DNA

Question 29

What is a mutagen?

Answer 29

An agent that causes mutations

Question 30

What are genetic diseases?

Answer 30

A condition or illness caused by mutations in genes or chromosomes

Question 31

What holds the chromatids together?

Answer 31

Centromere

Question 32

How is genetically engineered insulin is produced?

Answer 32

* Human cells contain a gene for making insulin. * DNA is extracted from human cells. * The insulin gene is cut out from DNA using a restriction enzyme. * Bacteria cells contain short circular pieces of DNA called plasmids. * The plasmid is extracted and cut using the same restriction enzyme. * The enzyme DNA ligase is used to join the ends of the insulin gene and the plasmid create recombinant DNA. * The plasmid holding the insulin gene functions as a vector and is used to transfer the insulin gene into bacteria. * The transgenic bacteria reproduce and start making insulin protein. * The insulin protein can be isolated and purified.

Question 33

What is a plasmid?

Answer 33

A short circular piece of DNA found in bacterial cells

Question 34

What is a restriction enzyme?

Answer 34

Enzyme that cuts DNA molecules at specific points

Question 35

What is DNA ligase?

Answer 35

Enzyme that joints cut ends of DNA molecules

Question 36

What is recombinant DNA?

Answer 36

DNA that has been created from different sources

Question 37

What is a vector?

Answer 37

The means of transferring DNA into an organism (e.g. a plasmid or a virus)

Question 38

What is a transgenic organism

Answer 38

An organism whose DNA has been genetically altered

Question 39

What are totipotent stem cells?

Answer 39

* Can form any cell type. | * From day 1 - day 5 of a zygote

Question 40

What are pluripotent stem cells?

Answer 40

* Can develop into most cells types | * From 1 week

Question 41

What are multipotent stem cells?

Answer 41

* Can develop into some cell types | * From foetus to adult

Question 42

Cuttings

Answer 42

* Remove a small part (stem or leaf) of the parent plant. | * Plant cutting into soul; it will then grow into a new plant.

Question 43

Micropropogation

Answer 43

* Take a few cells/very small parts from the plant (=explants). * Put them into culture medium (with nutrients and growth hormones). * Grow into a callus and from that into a new plant.

Question 44

Why does plant cloning work?

Answer 44

* Plants contain many meristem cells, which continuously divide by mitosis. * Meristem cells are. Totipotent and can differentiate into all kinds of other plant tissues.

Question 45

What are the advantages of reproducing transgenic (genetically modified) sheep by cloning?

Answer 45

* Ensures that all sheep are genetically identical. * Ensures all sheep have the gene for the characteristic (e.g. producing clotting agent). * More clotting agent is produced. * More sheep are produced. * Genetic modification of the animals does not have to be repeated.