Mendal's peas

Question 1

autosome

Answer 1

a chromosome not involved in determining the sex of the organism

Question 2

sex chromosome

Answer 2

a chromosome involved in determining the sex of the organism

Question 3

locus

Answer 3

specific position on the chromsome where a gene is located

Question 4

allele

Answer 4

alternative versions of the same gene eg: A, a

Question 5

trait

Answer 5

a characteristic of an organism (eg: seed colour)

Question 6

phenotype

Answer 6

the appearance of an organism

Question 7

genotype

Answer 7

• a genetic composition of an organism (AA,Aa,aa)

Question 8

homozygous

Answer 8

when 2 individuals carries 2 of the same allele at a locs

Question 9

heterozygous

Answer 9

individuals carries 2 different alleles at locus

Question 10

law of segregation

Answer 10

states that 2 copies of a gene segregate from each other during meiosis which gives rise to gametes

Question 11

meiosis genetic consequences

Answer 11

1. segregation of alleles
2. independent assortment of chromosomes
3. crossing over and recombination of alleles

Question 12

autosomal dominant

Answer 12

can have both homozygous genotype or heterozygous eg: BB or Bb

Question 13

autosomal recessive

Answer 13

Can only be homozygous recessive (bb)

Question 14

Incomplete dominance

Answer 14

• results in intermediate phenotype (one allele isn’t completely dominant to the other
• why> alleles code for alternate forms of a protein required for pigment production one red allele is only enough to make 50% pigment hence pink phenotype

Question 15

codominance

Answer 15

where the full effect of both alleles can be seen in the phenotype of the heterozygous individual

Question 16

Variations in dominance…

Answer 16

don’t negate mendel’s law of segregation they reflect differences in the way gene products control the production of phenotypes
- the type of dominance is dependent on the proteins encoded by the genes and their functions within a cell
- often a gene locus has more than 2 alleles