single factor causes

Question 1

what is the inheritance of genetic variants known as

Answer 1

Mandelian genetics

Question 2

what did Mendel experiment on

Answer 2

mice, bees, hawk wind (a flowering plant) and peas

Question 3

what did his work on peas show

Answer 3

showed that many characteristics showed repeatable patterns of inheritance

Question 4

what were the seven traits/characteristics Mendel looked at

Answer 4

• round or wrinkled
• yellow or green
• purple or white petals
• green or yellow unripe pods
• inflated or pinched ripe pods
• axial or terminal flowers
• short or long stems

Question 5

what did Mendel predict

Answer 5

• The concept of genes
• That genes occur in pairs
• That one gene of each pair is present in the gametes

Question 6

what does gene mean

Answer 6

•Gene– a unit of heredity; a section of DNA sequence encoding a single protein

Question 7

what does genome mean

Answer 7

the entire set of genes in an organism

Question 8

what does the term alleles mean

Answer 8

two versions of a gene that occupies the same position on homologous chromosomes and that cover the same trait

Question 9

what does the term locus mean

Answer 9

a fixed location on a strand of DNA where a gene is located

Question 10

what does the term homozygous mean

Answer 10

having identical alleles (one from each parent) for a particular characteristic

Question 11

what does the term heterozygous mean

Answer 11

having two different alleles for a particular characteristic

Question 12

what does the term Hemizygous mean

Answer 12

having a single allele on a sex chromosome

Question 13

what does the term Dominant mean

Answer 13

the allele of a gene that masks or suppresses the expression of an alternate allele; the trait appears in the heterozygous condition

Question 14

what does the term Recessive mean

Answer 14

an allele that is masked by a dominant allele; does not appear in the heterozygous condition, only in homozygous

Question 15

what does the term Genotype mean

Answer 15

the genetic makeup of an organisms

Question 16

what does the term Phenotype mean

Answer 16

the physical appearance of an organism (Genotype + environment)

Question 17

what does the term single cross factor mean

Answer 17

Single factor cross: a genetic cross involving a single pair of genes (one trait); parents differ by a single trait

Question 18

what does P stand for

Answer 18

parental generation

Question 19

what does F1 stand for

Answer 19

filial generation; offspring from a genetic cross

Question 20

what does principle of dominance mean

Answer 20

e allele masked another, one allele was dominant over the other in the F1 generation

Question 21

what does principle of segregation

Answer 21

when gametes are formed, the pairs of hereditary factors (genes) become separated, so that each sex cell (egg/sperm) receives only one kind of gene

Question 22

what can dominant alleles show

Answer 22

incomplete or co-dominance

Question 23

what does the test cross allow

Answer 23

allows the determination of genotype of individuals with a dominant phenotype (are the homozygotes or heterozygotes?)

Question 24

what did Mendels experiment show

Answer 24

experiments on pea plants showed that genes are present in pairs and that each gamete only receives a single copy of each gene

Question 25

what is cystic fibrosis

Answer 25

a lethal genetic disease affecting Europeans
•Caused by mutant recessive gene carried by 1 in 20 people of European descent (12M)
•One in 400 Europeans couples will be both carriers of CF – 1 in 4 children will have it
•CF disease affects transport in tissues – mucus is accumulated in lungs, causing infections

Question 26

describe the inheritance of cystic fibrosis

Answer 26

if two parents carry the recessive gene of Cystic Fibrosis (c), that is, they are heterozygous (C c), one in four of their children is expected to be homozygous for cf and have the disease:
CC = normal
Cc = carrier, no symptoms
cc = has cystic fibrosis

Question 27

give an example of co-dominance

Answer 27

AB blood type

Question 28

what does heterozygous codominance alleles exhibit

Answer 28

exhibit the phenotypes of both alleles

Question 29

what does heterozygous incomplete dominant alleles produce

Answer 29

produce an intermediate phenotype

Question 30

different alleles present different glycoproteins on red blood cell so give some examples

Answer 30

O is recessive to A & B
•A & B show co-dominance
•AO and AA individuals exhibit the A glycoprotein
•BO and BB individuals exhibit the B glycoprotein
•AB individuals exhibit both the A and B glycoproteins

Question 31

what are different variants of genes called

Answer 31

alleles

Question 32

what can Alleles be

Answer 32

dominant or recessive

Question 33

give examples are draw out some single genetic factors

Answer 33

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