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Flashcards in 3 Genetics Deck (57)
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1
Q

Allele

A

One of a number of alternative forms of a gene that can occupy a given gene locus on a chromosome. They differ from one another by one or only a few bases.

2
Q

Chromosome

A

Single long molecule of DNA, associate with protein, that carries the genes in linear order.

3
Q

Co-dominant

A

Pairs of alleles that both affect the phenotype when present in the heterozygous state.

4
Q

Dominant

A

An allele that has the same effect on the phenotype when in either the homozygous or heterozygous state.

5
Q

F1

A

first generation

6
Q

F2

A

second generation

7
Q

Gamete

A

General name for haploid sex cells, eggs, sperm cells and pollen grains.

8
Q

Gene

A

The basic unit of inheritance by which hereditary characteristics are transmitted from parent to off-springs. Section of DNA which codes for a specific characteristic.

9
Q

Genotype

A

The alleles possessed by an organism.

10
Q

Heterogametic

A

The gender that has two different sex chromosomes in the pair, XY. This is the male.

11
Q

Heterozygous

A

Having two different alleles at a gene locus.

12
Q

Homogametic

A

The gender that has an identical pair of sex chromosomes, XX. This is the female.

13
Q

Homologous

A

Chromosomes in a diploid cell which contain the same sequence of genes but are derived from different parents.

14
Q

Homozygous

A

Having two identical alleles at a gene locus.

15
Q

Locus

A

The specific position on a homologous chromosome of a gene.

16
Q

Monohybrid Cross

A

A genetic cross involving only one characteristic.

17
Q

Phenotype

A

The characteristics of an organism.

18
Q

Pure breeding

A

Having a homozygous genotype. Usually used to describe a dominant phenotype.

19
Q

Recessive

A

An allele that only has an effect on the phenotype when it is in the homozygous state.

20
Q

Sex chromosomes

A

The pair of chromosomes that control the sex or gender of the individual. In mammals and some other organisms these are the X and Y chromosomes.

21
Q

Sex linkage

A

The pattern of inheritance characteristic of genes located on the sex (X) chromosomes.

22
Q

Test Cross

A

Using a homozygous recessive to test a phenotypically dominant phenotype to determine if it is heterozygous or homozygous.

23
Q

Autosomes

A

The chromosomes other than sex chromosomes.

24
Q

Diploid

A

pairs of chromosome called homologous pairs

25
Q

Haploid

A

one chromosome from each homologous pair.

26
Q

Mutations

A

random changes in base sequence of DNA which give rise to new alleles.

27
Q

Genome

A

The whole of the genetic information of an organism

28
Q

Genome Size

A

The total length of DNA in an organism.

29
Q

The Human Genome Project

A

Determines the entire base sequence of all the human chromosomes

30
Q

Sickle Cell Anemia

A

Caused by a mutation in on of the haemoglobin genes. An amino acid GLUTANIC has been substituted by VALINE.

31
Q

Causes of mutations

A

Ionising radiation, X-rays, UV light and genic chemicals

32
Q

PCR

A

Polymerase Chain Reaction copies and amplifies small samples of DNA. Only specific section is amplified through the use of a primer which binds to the complementary regions of DNA.

33
Q

Restriction endonucleases

A

group of enzymes that recognise very specific sequences of DNA and cut both of the DNA stands at this point.

34
Q

Requirements for gene transfer 4

A

1- the insulin gene
2- a plasmid
3- a host bacterium (E.coli)
4- 4 enzymes

35
Q

Gene transfer (7)

A

1- plasmid cut with restriction enzymes to produce sticky ends
2- add insulin gene
3- join loose ends with ligase
4- recombinant plasmid- contains the plasmid genes plus the human insulin gene
5- insert into bacterium
6- bacterium cultured in large vat
7- filtered and purified: human insulin

36
Q

GMOs

A

genetic code is (nearly) universal so it can be transferred between organisms

37
Q

Benefits of GM

A

increase production- greater yield

resistant to a specific pest/ external element

38
Q

Risks of GM

A

developing resistance
spread of antibiotic resistance
mutations

39
Q

Risks of GM

A

developing resistance
spread of antibiotic resistance
mutations

40
Q

Clone

A

a group of cells or organisms that are genetically identical because they have come from a single parent.

41
Q

Cloning

A

naturally occurring- plants: cuttings/runners

animals- done after IVF: zygote divides and each will develop into an embryo

42
Q

SCNT 3

A

Somatic Cell Nuclear Transfer used to clone adult animals.
1- removes nucleus from body cell
2- transplant nucleus into enucleated egg cell
3- egg cell behaves like zygotes and develop into mature frogs

43
Q

Carrier

A

an individual that has a recessive allele of a gene.

44
Q

Pure/ true breeding

A

a parent where the dominant phenotype is homozygous.

45
Q

Pure/ true breeding

A

a parent where the dominant phenotype is homozygous.

46
Q

Mendel

A

pea-plant

47
Q

most gametes producing cells

A

are diploid

48
Q

alleles are in pairs

A

in pairs

49
Q

gametes are produced by

A

meiosis

50
Q

gametes are

A

haploid and contain one allele from a pair

51
Q

fusion of haploid gametes to form the zygote

A

restores the diploid number

52
Q

random fertilisation

A

mixes alleles

53
Q

Huntingdon’s

A

dominant

54
Q

Haemophilia

A

chromosome X- recessive

55
Q

Colour blindness

A

chromosome X- recessive

56
Q

Cystic fibrosis

A

Recessive

57
Q

Test Cross

A

to test whether a dominant phenotype is homozygous or heterozygous and ALWAYS crossed with the HOMOZYGOUS RECESSIVE