- Xylem contains tracheids, vessels, xylem parenchyma and xylem fibre.
- Tracheids: They are elongated, tubular dead cells with tapering end walls.
- Vessels: These are also known as trachea. They are elongated, tubular dead cells. They are joined to each other by end to end forming a continuous pipe. The cells are thick and lignified.
- Xylem parenchyma: They are also called wood parenchyma. This is the only living tissue of xylem.
- Xylem fibre: They are dead cells with thick walled fibre.
- Phloem consists of sieve tubes, companion cells, phloem parenchyma and phloem fibres.
- Sieve tubes: These are elongated, tubular living cells arranged in a row, with their perforated end walls forming a sieve. They are non-nucleated. Their protoplasm are inter-connected through sieve plates. They possess vacuoles.
- Companion cell: They are elongated, lens-shaped cells containing dense cytoplasm and prominent nuclei. These cells maintain connection with sieve cells through pits.
- Phloem parenchyma: They are living thin walled parenchyma cells.
- Phloem fibre: They are also known as bast fibre. They are elongated fibre like sclerenchymatous dead cells with thick walls containing pits and interlocked ends. Phloem fibre are the only dead cells in phloem.
Hope you could get an idea from here.
Doubt clarification - use comment section.
Every species is assigned a standard two-part name of genus and species. ... Organisms are grouped into species partly according to their morphological, or external, similarities, but more important in classifying sexually reproducing organisms is the organisms' ability to successfully interbreed.
Allele for gray fur is A (dominant)
Allele for white fur is a (recessive)
Genotype of heterozygous is Aa (heterozygous is gray, because its allele is dominant)
If we cross two heterozygous
<span>Parents: Aa x Aa
</span> <span>F1: AA Aa Aa aa</span>
The ratio between phenotypes is 3:1 (gray:white)
<span>AA Aa Aa are with gray fur</span>
<span>aa is with white fur </span>
The sepal of the plant... im pretty sure...
The clivage furrow forms, the chromosomes are on either side of the cell
