Bk 1 Ch 4 Inheritance

Question 1

Model organisms

Answer 1

Species that for a number of reasons I found favour in research laboratories

Eg. E.coli
S.cerevisiae
C.elegans
A. thaliana
D. melanogaster
M. musculus

Question 2

Eukaryotic Genome

Answer 2

Nuclear DNA in ch 4

Can be applied more widely to include DNA all organelles.

Question 3

Human has 23 chromosome pairs one pair of these are sex chromosomes. What are the non-sex chromosomes known as?

Answer 3

Autosomes.

Question 4

Homologous chromosomes

Answer 4

Pairs of autosomes, of equal length which carry an equivalent set of genes.

Question 5

What is the pair of sex chromosomes which differ in males and females known as?

Answer 5

Heterosomes

Question 6

Karyotype

Answer 6

The characteristic number and appearance of chromosomes in the nucleus of the cell from a particular species

Question 7

In prophase 1 of meiosis when the homologous chromosomes are actually physically paired together what is the process known as?

Answer 7

Synapsis

Question 8

What is the phenotype ratio characteristic of a heterozygous cross involving two genes located on different chromosomes that assort independently?

Answer 8

9:3:3:1

Question 9

Recombinant

Answer 9

In genetics, a cell or an individual with a new combination of gene alleles not found in either parent, usually applied to linked genes (on the same chromosome). In gene cloning, the product of inserting a DNA fragment from one organism into the DNA molecule of another. The resultant recombinant DNA molecule is a combination of the two.

Question 10

When given a table with number of plants from an F1 generation cross with a recessive homozygote how can you tell which of the Genotypes are recombinants?

Answer 10

The recombinant gametes occur at a much lower frequency than the non-recombinants

Question 11

Recombination frequency

Answer 11

Can be worked out from the percentage of different phenotypes at which recombination has occurred between the 2 gene loci

=( (a +b)/ total plants) x100%

Question 12

How to read a pedigree

Answer 12

For condition Try:
1 hypothesis Dominant asomatic gene
2 hypothesis Recessive asomatic gene
3 hypothesis Sex linked

Look at parents and offspring (use punnet square)

Question 13

Mitochondrial pedigree

Answer 13

Gene inherited from female

Check offspring

Question 14

Pure breeding plants

Answer 14

Those which when self crossed always yield progeny of the same phenotype as the parental plants

Question 15

Linkage

Answer 15

Where two genes are located on the same chromosome and are unable to assort independently during a genetic cross.

Question 16

Peel – breeding

Answer 16

Organisms that possess a particular characteristic or trait and which, when interbred over a number of successive generations, produce offspring which all possess that same trait. The genotype of a true breeding organism is homozygous.

Question 17

Nomenclature

Answer 17

All genes in italics

Dominant gene capital letter

If on same chromosome 2 genes linked eg Pl

If on homologous pair chromosomes - / between them eg Pl/pL