A salmon can live out of water for 2 hours
<span>1.
</span>Cones perceive
light in color while rods perceive light in black and white.
<span>2.
</span>Rods can perceive dim light, unlike cones. The rods are located at the edges of the eyes. This is why it easier to perceive an image in the dark through
the corner of the eyes.
<span>3.
</span>The discs that compose the cones are usually
partially open to the surrounding vitreous
fluid while those of the rods are closed.
C. membrane bound organelles and no distinct nucleus
1. Interphase is an important and the longest phase of the cell cycle during which the cell prepares for division by coping its DNA. It is metabolic phase of the cell, in which the cell grows, obtains nutrients and metabolizes them. There are three stages of interphase: G1 (the cell growth), S (replication of DNA, chromosomes are copied) and G2 (preparation for division). Without this phase, genetic material wouldn’t be ready for the process of meiosis and haploid gametes couldn’t be created.
2. Homologous chromosomes are the similar but not totally identical chromosome pairs that an organism receives from its two parents. During the prophase I of meiosis they pair up: each chromosome aligns with its homologue partner via link-chiasmata ( the two match up at corresponding positions). Those homologue pairs separate during a first stage of cell division (meiosis I-reduction of chromosomes number, from diploid to haploid), while sister chromatids separate during a second stage (meiosis II).
3. Crossing over is a process in which homologous chromosomes trade their parts. Crossing over is process of genetic recombination where DNA is cut and then repaired. Cut and repair of homologous chromosomes allow them to exchange some of their genetic information. As a consequence of crossing over, new arrangement of maternal and paternal alleles on the same chromosome is achieved. It is the way to create varations.
4. During the metaphase I, homologue pairs are lined up comparing to metaphase II where individual chromosomes are lined up. It is because during the meiosis I homologue pairs separate and chromosome number reduce from diploid to haploid. On the other hand, during the meiosis II, sister chromatids separate.
5. Nondisjunction is the consequence of cell division, where there is no properly separation. There are different forms of nondisjunction:
• failure of a pair of homologous chromosomes to separate in meiosis I,
• failure of sister chromatids to separate during meiosis II.
After nondisjunction, resulting daughter cells are with abnormal chromosome numbers -aneuploidy.
Answer:
1st) Sagittarius Dwarf Elliptical Galaxy
2nd) Virgo Stellar Stream
3rd) Canis Major Dwarf
4th) Milky Way Galaxy
Explanation: