D. This is to “proofread” the DNA
The paramecium has two nuclei, a big and small one. The big one operates as the director of the cell's activities, rather like a little brain. The smaller one is used for reproduction. The paramecium splits in half (fission) just as the ameba does. First the smaller nucleus splits in half and each half goes to either end of the paramecium. Then the bigger nucleus splits and the whole paramecium splits. Occasionally two paramecium exchange material and form a new paramecium. This is called conjugation.
<span>Conjugation in Paramecia occurs in the following way: </span>
<span>a). The formation of ciliary contacts. </span>
<span>b). Local loss of cilia and formation of narrow contacts between anterioventral somatic cell membranes </span>
<span>c). Formation of small cytoplasmic bridges (which allow for the exchange of molecular components only). </span>
<span>d). Their enlargement enables the cells to exchange micronuclei. </span>
<span>Bacteria exchange plasmid material and the Paramecia exchange micronuclei.
Good luck to Steve! How is it in Neptune? XD</span>
Answer:
plasmodesmata
Explanation:
Plasmodesmata are channels between adjacent plant cells, while gap junctions are channels between adjacent animal cells. However, their structures are quite different. A tight junction is a watertight seal between two adjacent cells, while a desmosome acts like a spot weld.
Answer: A. ancestral trait
Explanation:
Bipedalism can be define as a form of terrestrial locomotion, in which the organism moves with the help of two rear limbs or legs. Typical bipedal movements includes the hoping, running and walking. The evolution of the human bipedalism occurred in primates in about 4 million years ago with Sahelanthropus (oldest human ancestors or African Apes). The human ancestor Sahelanthropus led to the morphological alterations in the human skeleton including changes in the bones such as size of the bones of the foot, knee size, shape and orientation of the vertebral column, and leg length. All these changes contributed to the bipedalism.
The correct answer should be Diffusion.
