Answer:
10 chromosomes/sister chromatids
Explanation:
Prophase is the first stage of cell division (mitosis). Prior to the cell entering the actual division stage, it undergoes a phase where it prepares its content and most importantly undergo the duplication of its genetic material (DNA). This DNA are found as chromosomes. It undergoes replication of its DNA in the S-phase of interphase stage.
Since Arabidopsis thaliana has 10 chromosomes, and each chromosome holds one DNA molecule, 10 molecules of DNA will be present in the mustard plant's genome. These 10 molecules of DNA will be replicated on another copy of chromosome which is identical to the template. This chromosomes are called SISTER chromatids i.e. replicated chromosome. Each sister chromatids are held together at the centromere and are considered one individual chromosome until they separate during anaphase stage.
Hence, at the Prophase stage, before separation, each sister chromatid (replicated chromosome) is considered as one chromosome. Thus, in the mustard plant with 10 chromosomes, it will possess 10 sister chromatids or chromosomes at the Prophase stage.
N.B: When sister chromatids separate during anaphase stage, they will be regarded as individual chromosomes.
He never liked being on the hot seat and he'd found his niche<span> with this job.</span><span>
</span>
<h3><u>Answer;</u></h3>
A. Gas exchanges takes place by diffusion.
B. It is an open system.
<h3><u>Explanation</u>;</h3>
- Most molluscs and arthropods have an open type of circulatory system.
- Open circulatory systems pump blood into a hemocoel with the blood diffusing back to the circulatory system between cells.
- Blood is pumped by a heart into the body cavities, where tissues are surrounded by the blood.
B seasonal variations in climate tend to increase with distance from the equator
