Gregor Mendel was the "father of modern genetics" and helped disprove the blended theory of inheritance.
sunlight is a reactant in photosynthesis
An _observation_ is taken using the senses
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.
<h3>
Most railroad tracks are built from pieces of steel supported by wooden ties, and laid with a gap between the ends. </h3>
Explanation:
The reasons are:
Firstly , the thermal expansion of solid at higher temperatures.
During the summer season, the steel tracks may expand due to thermal expansion and if gaps are not laid the tracks will bend and lead to accidents.
Secondly, imbibition of water during rainy season.
During the rainy season the wooden tracks will imbibe water and swell. If gaps are not provided, this may result irregular levels of railway track. This may prove very dangerous and lead to railway accident.
