Answer:
d
Explanation:
<em>Crossing over shuffles alleles on non-sister chromatids of homologous chromosomes.</em>
At the prophase I stage of meiosis, homologous chromosomes synapsed to form a four-chromatid structure known as tetrad. Exchange of chromosomal segments between non-sister chromatids of the tetrad then takes place, a process that results in the reshuffling of genes or alleles on the non-sister chromatids.
Hence, none of the answers is correct.
Correct option: d
As a result the bacterial cells switch off transcription of genes involved in the production of tryptophan because the amino acid binds to the REPRESSOR.
Answer:
1-The respiratory system is the network of organs and tissues that help you breathe. It includes your airways, lungs and blood vessels. The muscles that power your lungs are also part of the respiratory system. These parts work together to move oxygen throughout the body and clean out waste gases like carbon dioxide.
2-The fluid represents the outermost layer of the alveolar surface that is directly exposed to air and thus to the environment. Alveolar fluid prevents desiccation of the epithelial cells and also functions as a physical protection barrier against inhaled particles and irritants.
3-The main function of surfactant is to lower the surface tension at the air/liquid interface within the alveoli of the lung. This is needed to lower the work of breathing and to prevent alveolar collapse at end-expiration.
4-The trachea (windpipe) conducts inhaled air into the lungs through its tubular branches, called bronchi. The bronchi then divide into smaller and smaller branches (bronchioles), finally becoming microscopic. The bronchioles eventually end in clusters of microscopic air sacs called alveoli.
5- i havent seen the video then how can i answer q5