mendels laws pt1

Question 1

mendel discovered heredity by:

Answer 1

-breeding garden peas
(why peas?)

Question 2

how did mendel control matings?

Answer 2

-peas normally self polinate
-male (stamens)make sperm and female(carpels) produce eggs
-he removed male ograns to prveent slef-pollination and used pollen frm another flower to fertlize another=cross-pollination

Question 3

what did mendel find by crossing a purple flower with a white

Answer 3

-f1 gen was all purple even tho they were hybrids
-f2 gen (allowed f2 to self pollinate) we had 705 peurple flowers and 224 white fowers –3:1 ration of purple to whure in f2 gen

Question 4

what did mendel refer to as genes

Answer 4

heritable factor

Question 5

axial vs terminal flowers

Answer 5

axial are on side of stem
terminal shoot out the top

Question 6

when we have a homologous pair of maternal and paternal unreplicated chroms, which phase is the cell in?

Answer 6

g1 phase

Question 7

alleles

Answer 7

=alternative versions of a gene
-varioations in a genes nucloetide sequence

Question 8

each gene resides at a specific location or ___ on the chrom

Answer 8

locus

Question 9

for each character am organims inherits __ alleles, ___

Answer 9

-2
-one from each parent
- mendel made this deduction without knowing the role of chroms!!!!!

Question 10

true breeding plants

Answer 10

• meaning the two allleles at a locus are identical (such as the plants in the parent, P, gen in mendels experiemnt)

Question 11

law of independent assortment (of alleles)

Answer 11

each trait assorted independntly to gametes

Question 12

dihyrbid cross

Answer 12

genetic cross where both parents are hetero for 2 traits
eg) RrYy x RrYy
-phenotypic ratio: 9:3:3:1
(9=both dom, 3= one dom and one rec, 1=both rec)

Question 13

whencrossing an organism that is homo rec for a single trait w a hetero, the chance of producing an offspring that is homo recessive phenotype is:

Answer 13

50%

Question 15

in which situations do inherited genes not follow mendelian patterns?

Answer 15

-when alleles arent completely rec or dom
-when a gene has 2+ alleles (eg. blood type)
-epistatis and pleitropy
-enviornmental impact on phenotype (eg. change in flower colours due to acidity of soil)

Question 16

epistatic factor

Answer 16

a gene that supresses the other gene (eg, the ee gene is labs produces zero pigment in the fur coat so regardless of if the other gene is dom for black or homo rec for brown, its gonna be a pigmentless coat=yellow.

You might have a gene that says your hair will be brown, but if there’s another gene that prevents pigment from forming, your hair could turn out white or albino instead. The second gene “overrides” the first one

Epistasis means one gene controls or masks the effect of another gene.

Question 17

pleiotropy

Answer 17

-no punnet square associated
-ability of one gene to have multiple phenotypic effects.
eg)sickle cell

Question 18

environmental effect on phenotype

Answer 18

=norm of reaction is the phenotypic range of genotype influenced by the enviroenmtn.
eg) hydrangea flowers of the
same genotype range from blue-violet to
pink, depending on soil acidity