Answer:
1. They must be removed before sister chromatids or homologous chromosomes can separate
Explanation:
During the S-phase of the cell cycle, not only does DNA have to be replicated, but also newly synthesized DNA molecules have to be connected with each other. This replicated DNA (sister chromatids) remain physically connected with each other from S phase until metaphase. This physical connection is called Sister chromatids cohesion.
Sister chromatid cohesion depends on COHESIN, a tripartite protein complex that forms a ring structure to hold sister chromatids together during mitosis and meiosis. Cohesin regulates the separation of sister chromatids during cell division, either mitosis or meiosis. This sister chromatid cohesion is essential for the biorientation of chromosomes on the mitotic or meiotic metaphase spindle, and is thus an essential prerequisite for chromosome segregation. Without the cohesion, sister chromatids would not be segregated symmetrically between the forming daughter cells, resulting in aneuploidy.
Cohesion is established during S-phase of DNA replication, and the cohesins hold the sister chromatid together after DNA replication until anaphase when the removal of cohesin leads to separation of sister chromatids (meiosis II and mitosis) and homologous chromosomes (meiosis I).
Answer:
D.
Explanation:
Solar energy is needed for photosynthesis, and chemical energy in the form of glucose is needed for cellular respiration.
Aspects such as genetic engineering have allowed for
engineering of transgenic organisms such as bacteria to produce bioproducts
such as insulin to addresses medical disorders
such as diabetes. Another is the innovation of whole-genome sequencing that allows researchers
to determine genetic predisposition of a particular person to particular diseases.
Answer:
Photogenic means looking attractive in photographs or on film. Photography means a picture made using a camera, in which an image is focused onto film or other light-sensitive material and then made visible and permanent by chemical treatment, or stored digitally.
Answer:
Conduction
Explanation:
convection- not related, as it is hot air rising and cold air falling, which isn't happening.
Subduction- that has to do with the Earth's plates moving
Radiation- doesn't have to do with heated substances.
