Mandelian genetics

Question 1

What is genetics

Answer 1

science that deals with heredity and variation

Question 2

Whats Heredity

Answer 2

Passing of traits from one generation to the next

Question 3

Traits are either

Answer 3

Inherited or acquired traits

Question 4

What is the difference in inherited and acquired traits

Answer 4

Inherited traits: passed on from family
(ex. hair type/colour, skin colour, facial features)

Acquired traits: Traits that develop after birth and are not passed on but develop from environment

Question 5

What are Alleles
> example
> types

Answer 5

Alleles is a version of a gene , one from each parent
> Ex. gene is height, alleles are wether tall or short ( type of alleles inherited from parents)
> Dominant , big letter and recessive, small letter
(ex, T for tall, t for short)

Question 6

What is homozygous
> example

Answer 6

2 copies of the same Allele , same so no dominant or recessive one
> Ex. TT or tt

Question 7

What is heterozygous
> example
> which is dominant

Answer 7

Two different alleles for 1 gene
> Ex. Tt
> big T always wins and is more dominant, not inbetween if Tt but tall

Question 8

What is a genotype
> example

Answer 8

genetic makeup of a individual , two alleles
> ex. TT or Tt or tt

Question 9

Whats a phenotype
> example

Answer 9

What is seen, expression of a genotype/gene
> ex. short or tall, blue eyes or brown

Question 10

Who is Gregor Mandel and what did he do

Answer 10

Austrian monk that worked with peas to develop the mandel laws and find out about genetics
(Father of genetics)

Question 11

Mandel’s Laws
1- Law of doninance
2- Law of Segregation
3- Law of independent assortment

Answer 11

1- Traits are controlled by a pair of factors (alleles) and one factor can be dominant over the other, recessive

2- All individuals have two copies of a gene, these copies segregate during gamete formation and each gamete(sperm/egg) receives one copy of each gene

3- Two alleles for one gene segregate(assort) independently of the alleles for other genes during gamete formation ( one gene for eye colour wouldn’t have effect or tall short gene, happen independently)

Question 12

Monohybrid Cross expiriment , variables and outcome : genotype and phenotype with purple (P) and white (p) flowrrs
> F1
> F2

Answer 12

1 trait cross: P- purple (d) and p - white (r)
> P generation ( parental) , purple x white flowers

> F1 generation, first mix and dominant wins over so all flowers are purple,
(PP x pp = Pp) first generation all Pp ( genotype) and display as purple (phenotype) bc thats dominant

> F2 generation, second mix (PpxPp= Pp, pp and PP) 3 genotypes but 2 types of phenotype, 3:1 ratio purple: white , 3 display as purple and 1 as white

Question 13

What are Punnett squares

Answer 13

square diagram used to predict genotype of a particular cross

Question 14

Mandel’s law of dominance

Answer 14

traits ate controlled by a pair of factors (alleles) and one factor can mask the other (sominant and recessive

Question 15

Mandel’s law of segregation

Answer 15

All individuals have two copiez of a gene. paired allels separate during gamete formation (meiosis) and each recives one copy

Question 16

Mandel’s Law of independent assortment

Answer 16

Two allels for one gene segragate (assort) independently of other genes during gamete formation (proven wrong)

Question 17

Whats a test cross

Answer 17

to determine an unknown dominant genotype cross with a known one: homozygous recessive, helps us determine if unknown is homo or heterozygous

Question 18

What are the patterns of inheritance in monohybrid crosses

Answer 18

Multiple alleles , Incomplete dominance , co dominance

Question 19

Whats the pattern of inheritance: multiple alleles in monohybrid crosses

Answer 19

When genes have more than two forms
capital letters with subscript letters used
ex. allels a qnd b for blood dominant over o but even to eachother

Question 20

What is incomplete dominance in monohybrid crosses:

Answer 20

When two allels are equally dominant and when they interact they form a new phenotype which expresses a combination of traits
ex. Red + White = Pink

Question 21

What is co dominance in monohybrid crosses

Answer 21

When both parent allels get expressed as a combination of both
no new phenotype just both of the parent phenotypes

Question 22

What are dihybrid crosses

Answer 22

cross involving two indapendent traits present in alternate forms
indapendent traits are found on different chromosomes

Question 23

phenotypic ratio:

Answer 23

if parents heterozygous for both traits you get 9:3:3:1 phenotypic ratio

Question 24

Polygenic inheritance is

Answer 24

trait controlled by 2 or more genes, can have multiple alleles and show incomplete or co dominance and can be affected by environment

Question 25

What are epistatic traits
ex

Answer 25

a gene that masks expesssion of another gene or genes
ex. Albanism dominant

Question 26

what is selective breeding and why do we do it

Answer 26

breeding closley related individuals (inbreeding) for a desirable trait or to eliminate a undesirable one , offspring are homozygous for most traits

Question 27

Whats a pedigree used for

Answer 27

to predict the genotype of a given individual or determine the mode of inheritance of a particular trait

Question 28

autosomal inheritance traits travel

Answer 28

on chromosome 1-22

Question 29

What is autosomal dominantant
> located
> whos affected and generation
> unaffected individuals child

Answer 29

Dominant means a single copy of the mutated gene is enough to cause disorder
>gene is located on chromosomes 1-22
>both males and females affected
>2 unaffected individuals will have unaffected child
> trait appears in all generations

Question 30

Autosomal recessive is
> located
> whos affected
> generation
> affected parents produce ut

Answer 30

Recessive traits means inheriting a mutated gene from Both parents causes disorder
> chromosome 1-22
> both males and females affected
> trait skips generations-
>one / two affected parent dosent always produce affected child b

Question 31

Sex linked recessive traits
> affected vs unaffected

Answer 31

only males affected, trait skips generations
> Affected males XbY unaffected XBY
females can be carriers = affected XbXb