Fertilization takes place when a sperm joins a(n)

nucleus
egg
dna
cell

question 30 (multiple choice worth 1 points)

the gene for tongue rolling is dominant. the mother’s genotype is tt, and the father’s genotype is tt. what are the chances that he will be able to roll his tongue?

25% chance
50% chance
75% chance
100% chance

question 31 (multiple choice worth 1 points)

a gene that has two dominant traits is known as

double dominant
codominant
di-dominant
multi-dominant

Q1. The answer is egg.

The fertilisation is a fusion of two gamete cells which results in the formation of the zygote. Sperms and eggs are gamete cells, male and female, respectively. After a sperm and an egg fuse, i.e. the fertilisation takes place, a zygote is created and then begins a development of an embryo.

Q31. The answer is 100% chance

Alleles:
T - the dominant allele for the tongue rolling
t - the recessive allele

Genotypes and phenotypes:
TT - people able to roll tongue 
Tt - people able to roll tongue
tt - people not able to roll tongue

The mother’s genotype is TT and the father’s genotype is TT. The offspring will get T allele from the mother and T allele from the father:
Parents:            TT        x         TT
Offspring:     TT      TT      TT         TT

So, all of the offspring will have genotype TT and will be able to roll their tongues.
 

Q32. The answer is codominant.

A codominance is a pattern of inheritance in which both alleles of a gene are expressed. So, there are no dominant and recessive alleles and both will affect the phenotype. For example, plants with alleles for both red and white flowers will have flowers that are both red and white.