Answer:
eukaryotes that ensures that the number of chromosomes will not double from parent to offspring when gametes fuse during fertilisation. Homologous pairs of chromosomes separate in meiosis I, so the gametes are haploid (n), and each gamete receives only one member of each chromosome pair.
Explanation:
I hope this helps!
In order to survive the winter, monarch butterflies "migrate to warmer areas".
<u>Option: B</u>
<u>Explanation:</u>
- The survival for Monarch butterflies is not possible in any of the United States 'cold winters, therefore they are needed to migrate south and west every autumn to avoid the cold temperatures.
- This species migration usually begins around every year in October, but may begin quicker if the weather turns cold earlier than that.
- Thus they spend their winter hibernation all year round in Mexico and some areas of Southern California where the temperature is warmer.
- If the monarch stays in the Eastern states, typically east of the Rocky Mountains, then they will migrate to Mexico and hibernate in <em>oyamel fir</em> trees.
To first dive into your question, here are some vocabulary terms that I will be using and will be helpful to you as well.
- Homozygous dominant (BB): <em>Is not affected by cystic fibrosis</em>.
- Homozygous recessive (bb):<em> Is affected by cystic fibrosis</em>.
- Heterozygous (Bb):<em> A carrier for cystic fibrosis</em>.
- Phenotype (Ex: Having cystic fibrosis): <em>The appearance of an allele pair</em>.
- Genotype (Ex: bb): <em>The genetic makeup of an allele pair</em>.
We know that if both of the parents are phenotypically normal, there is no way that they can be homozygous recessive (bb), or have cystic fibrosis. We also know that since they have a child with this disease, they can't be homozygous dominant (BB) either. This means that <u>both parents have to be carriers (Bb)</u> in order for them to have a child with cystic fibrosis.
Below I have attached a Punnett square with both of the heterozygous parents.
<em>Each child they have will have a </em><u><em>1/4</em></u><em> or </em><u><em>25%</em></u><em> chance of having cystic fibrosis.</em>