Inheritance

Question 1

What is a gene with more than one allele called?

Answer 1

polymorphic

Question 2

alleles are either?

Answer 2

dominant or recessive

Question 3

Monogenetic condition

Answer 3

disease caused by one single gene

Question 4

Second law of mendelian inheritance

Answer 4

• alleles of different genes divided across gametes independently
• parental traits = Gen 2
• not always true
• applies to genes that are on diff chromosomes

Question 5

Non- mediated inheritance

Answer 5

multiple alleles, incomplete dominance, co- dominance, pleiotropic allele,

Question 6

Co- dominance alleles

Answer 6

produce phenotypes that both appear in heterozygotes

Question 7

Pieotrophic allele

Answer 7

one allele has multiple phenotypic effects

Question 8

Epistasis

Answer 8

One gene alters the phenotypic expression of another gene

Question 9

Polygenic traits

Answer 9

Traits controlled by multiple genes

Question 10

Incomplete penetrace

Answer 10

variable phenotypic expression of a genotype

Question 11

Example of polygenic trait

Answer 11

height in humans

Question 12

Two processes introduce variation

Answer 12

Mutation, recombination

Question 13

what is a mutation

Answer 13

a heritable change in the genetic information of a cell or organism

Question 14

What is recombination

Answer 14

the rearrangement of genetic material. this happens during sexual reproduction

Question 15

spontaneous causes of mutation

Answer 15

• chemical reactions that alter nucleotides
• errors in DNA replication
• errors during meiosis

Question 16

induced causes of mutation

Answer 16

damaging chemicals
- ionising or UV radiation

Question 17

what are induced mutations caused by?

Answer 17

mutagens

Question 18

Frame shift point mutation

Answer 18

insertion or deletion of one or two bases will alter the reading frame

Question 19

Missense point mutation

Answer 19

changes a codon into one that specifies a different amino acid, the amino acid sequence of the encoded protein is affected

Question 20

Synonymous (silent) point mutation

Answer 20

there is a redundancy in the code as there 64 codons but only 20 amino acids
- amino acid is unaffected

Question 21

nonsense point mutation

Answer 21

changes a codon that specifies an amino acid into a stop codon
- translation is terminated prematurely
- resulting in a truncated protein

Question 22

Chromosomal mutations can be due to;

Answer 22

• deletion
• duplication
• inversion
• insertion
• translocation

Question 23

Molecular characteristic of the mutation

Answer 23

point mutation
chromosomal mutation

Question 24

Function of the encoded protein

Answer 24

silent, loss or gain of function

Question 25

a mutation can be silent because…(encoded)

Answer 25

• mutation doesn’t alter the amino acid sequence
• mutation causes change in the sequence that has no effect on the function of protein

Question 26

Loss of function mutation (encoded)

Answer 26

• results in a change in the amino acid sequence that impairs normal protein function
• shows recessive inheritance

Question 27

Gain of function… (encoded protein)

Answer 27

• change leads to abnormal functioning protein
• shows dominant inheritance as wild type allele encoding for normal protein is often not able to prevent the abnormal activity of mutant protein