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.
All species in the same area
Answer:
G A A T C C G A A T G G T
Explanation:
C=G
G=C
A=T
T=A
Answer:
Planarian
Explanation:
The design of the planarian is gentle, flat, and saddle, and it can be jewish, grey, blue, grey, or white. Two alleviation eyespot pigmented zones light intensity, are located on the flippant, triangle curvy head.
Answer: Please see the explanation column for answers
Explanation:
A reflex arc is a nerve or neural pathway that controls a reflex action giving fast response to a stimulus without the conscious act of the brain. Here, the sensory neurons receive stimulation then synapses or connects to spinal motor neurons nerve cells which then connects to muscle cells acting as effectors.
Ranking the events that occur in the reflex arc in correct order gives
1st ---- A sensory receptor detects a stimulus
2nd---A sensory neuron conducts action potentials through the nerve to the spinal cord
3rd----- The sensory neuron synapses with an interneuron
4th----- The interneuron synapses with a motor neuron
5th------- The motor neuron conducts action potentials through the anterior root and spinal nerve to an effector organ.
