- 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.
Answer:
True.
Explanation:
Earthquake proof buildings are those which have the ability to stand during an earthquake. Shock absorbers that is present between the building and the ground motion, able the building to remain upright during an earthquake. The shock absorbers has the ability to absorb all the disturbance produced in the building and for that purpose the building is safe.
Answer:
Sudden Influx of Nutrients
Explanation:
Algal blooms are caused by a sudden influx of nutrients, coupled with already warm temperatures. This can happen from fertilizer runoff from farms or chemical industry waste. They allow algae to quickly grow, but the water reaches carrying capacity.
Answer:
a. S represents allele for short hair while s represents allele for long hair.
b. Ss (male) × ss (female)
c. 50% Ss, 50% ss
d. 3 long hair (ss), 3 short hair (Ss)
Explanation:
This question involves a single gene coding for hair length in guinea pigs. The allele for short hair (S) is dominant over the allele for long hair (s).
a. Letter "S" will represent the allele for short hair while letter "s" will represent the allele for long hair.
b. According to this question, a heterozygous male is crossed with a long-haired female. The genotype of the male guinea pig is "Ss" while that of the female is "ss". (see attachment for the punnet square)
c. The possible genotypes of the offsprings in this cross are: Ss and ss, each carrying 50% each as they are produced in a ½ Ss: ½ ss.
d. Since 50% of the offsprings will be both short haired and long haired, If they have six babies, 3 of them will be short-haired while 3 of them will also be long-haired.
Every species has different timespans. Some butterflies live 6 months, other live 7 years. However, most of their time they are caterpillars or are in a coccoon. Up to 6 years
