The plant cell is the smallest living structure and constituent unit of all plants. Its size and shape vary by function. It is composed of several organelles, all useful to its activity.
The right answers are: (the numbers are in the picture).
1 refer to a vacuole.
2 refer to a cell wall (if you see closer, the arrow is aiming the green layer, the yellow one is the cell membrane).
3. refer to a chloroplast.
4. refer to mitochondria.
Answer:
If you are referring to a cellular organelle than I would say lysosomes because, they do just that, they digest intracellular waste.
Answer:
The correct answer is B. DNA helicase first unwinds the double helix around the +1 site.
Explanation:
The helicase is an enzyme that specifically breaks the hydrogen bonds of the bases in the transcription process. As E. Coli is a prokaryote, then, the transcription only occurs in one point of the circular DNA. The promoter region indicates where the DNA polymerase has to start replicating and the Topoisomerase unwinds the parts of the DNA that are being excessively twisted because of the separation of the two strands.
Answer:
The diameter of the xylem vessels should be small in order for the capillary action to take place.
Explanation:
The vessels through which water is transported to different parts of the plants and trees are the xylem. Water is transported in the trees through a mechanism named as capillary action. This mechanism can occur only if the diameter of the vessels are small.
The water molecules adhere to the walls of xylem and an upward force is generated. If the diameter of the vessels i.e xylem would be small then the surface tension between the xylem and water molecules would be enough to move the water in an upward direction.
Answer:
C. II and IV only
Explanation:
X linked recessive inheritance follows the criss-cross pattern in which affected mothers always have affected sons as sons get their X chromosome from mothers only. Condition "II" can not be true for X linked inheritance as hemophiliac mothers (XhXh) should have hemophiliac sons (XhY) only.
Daughters get one copy of their X chromosome from the father and the other from mother. To have affected daughters, mother should be carrier or hemophiliac and the father should be hemophiliac (XhY). This would make it possible for both the parent to transmit one copy of X chromosome with the gene to daughters (XhXh).
