<span>In this item, we are asked to reason out as to why crossing over add to the genetic diversity of the sexually reproducing organisms. The answer to this question is that it is the exchange of genetic material between homologous chromosomes resulting in recombinant chromosomes. The answer to this item is letter B. </span>
Answer:
A. selective pressures that favor certain individuals
Explanation:
Answer: the name used is polytene chromosomes.
Explanation:
Polytene chromosomes are produced when repeated rounds of deoxyribonucleic acid (DNA) replication without cell division forms a giant chromosome, they have thousand of DNA strands and provides high level of function in the salivary glands.
At interphase, polytene chromosomes are seen to have distinct thick and thin banding patterns, these bands are of 2 types, the dark band (dark stained,
contains more DNA and less RNA) and the interband (light stained, more RNA and less DNA). The bands enlarge and forms a swelling called puff in certain times, the puffing (which is the formation of puff) is caused by the uncoiling of individual chromomeres in a band. The puffs indicate the site of active genes where mRNA synthesis takes place. These distinct banding patterns are used to study the function of genes in transcription because they permit high level of gene expression.
The statement “Feeding scrub-jays can lead to starvation of fledgling scrub-jays” is true because if humans feed the birds, they may become reliant on humans and be unable to get their own food, which can lead to starvation and malnutrition
