Healthy individuals of Paramecium bursaria contain photosynthetic algal endosymbionts of the genus Chlorella. When within their
hosts, the algae are referred to as zoochlorellae. In aquaria with light coming from only one side, P. bursaria gather at the well-lit side, whereas other species of Paramecium gather at the opposite side. The zoochlorellae provide their hosts with glucose and oxygen, and P. bursaria provides its zoochlorellae with protection and motility. P. bursaria can lose its zoochlorellae in two ways: (1) if kept in darkness, the algae will die; and (2) if prey items (mostly bacteria) are absent from its habitat, P. bursaria will digest its zoochlorellae. Theoretically, P. bursaria can obtain zoochlorellae either vertically (via the asexual reproduction of its mother cell) or horizontally (by ingesting free-living Chlorella from its habitat). Consider a P. bursaria cell containing zoochlorellae but whose habitat lacks free-living Chlorella. If this cell subsequently undergoes many generations of asexual reproduction, if all of its daughter cells contain roughly the same number of zoochlorellae as it had originally contained, and if the zoochlorellae are all haploid and identical in appearance, then which statement is accurate?
<em>Zoochlorellae</em> also reproduced asexually at a nearly constant rate
Explanation:
<em>Zoochlorellae</em> (singular <em>Zoochlorella</em>), also referred to as <em>Chlorella</em>-like algae, is a genus of algae that live inside freshwater protozoans (e.g., <em>Paramecium bursaria</em>), exhibiting a symbiotic association with their hosts. Asexual reproduction is a type of reproduction that produces new individuals without the fusion of gametes and does not involve a change in the number of chromosomes. In consequence, a haploid parent, i.e., an individual who contains a single set (n) of chromosomes, will produce haploid (n) offspring. Moreover, and since the question indicates that daughter cells contain approximately the same number of zoochlorellae cells as parent cells, it is expected to observe an asexual reproduction rate at a fairly constant rate over time.
Toxicity can be measured by the effect the substance has on an organism, a tissue or a cell. We know that individuals will respond differently to the same dose of a substance because of a number of factors including their gender, age and body weight. Therefore a population-level measure of toxicity is often used
By age group, in 2019, the number of new HIV diagnoses was highest among people aged 25 to 29. From 2015 through 2019, HIV diagnoses increased among persons aged 13-24 years, 35-44 years, and 45-54 years.
It distributes food and water throughout the whole body
Explanation:
Vascular Tissue is the circular system of plants. It distributes water and food throughout the plant and removes waste through the roots and stomata. The vascular tissue is composed of two transport systems: xylem and phloem
When stating a routine request up front, what you should do
is as you have your request told, you should assume that the audience present
in the situation will be able to comply with the routine request that you have
asked or suggested.
