They do not have a distinct head and thorax but a fused version of the two called a cephalothorax. That's one of the major differences between insects and crustaceans, both being subgroups of arthropods.
Explanation:
The phenotypes and genotypes of the progeny can be determined by a dihybrid cross of the parents.
The heterozygous male will have the genotype 'SSww' and the heterozygous female will have the genotype 'ssWW'.
When crossed, the F1 offsprings will have a hybrid genotype of 'SsWw'. These offsprings are heterozygous with spotted skin and wooly hair.
On self-crossing of the F1 hybrids, we find four different combinations of the alleles- SW, Sw, SW and sw. The probability of getting each of these combinations is 1/4.
Hence, the probability of any dihybrid type is 1 out of the 16 possible genotypes. Using Punnet square, we find
9 SSWW: 3 SSww: 3 ssWW : 1 ssww
This is the phenotypic ratio of the offsprings.
The ratio of the possible genotypes will be 1:2:1:2:4:2:1:2:1.
Answer:
C. Endocrine System
Explanation:
Simply put, the endocrine system is a network of glands that secrete chemicals called hormones to help your body function properly. Hormones are chemical signals that coordinate a range of bodily functions. The endocrine system works to regulate certain internal processes.
In order for offspring to have a dominant mutation, they need at least one copy of the allele from either or both parents. So yes, at least one of the parents must have the mutated gene in order for the offspring to have the mutation.
For your second question, I'm not quite sure what you mean so I will restate two possibilities for what I think you mean:
1. The offspring does not have the mutation if none of the parents have the mutated gene: this is correct.
2. If the mutation is recessive and the child has only one copy of the mutated allele, then the child will not show the mutation. If none of the parents had the mutated gene, then it would not be possible for the child to have the mutated gene or show it.
