Biology Test - 4

A = Kinetochore - It is a complex of proteins associated with the centromere of a chromosome during cell division, to which the microtubules of the spindle attach.

B = Spindle - Spindle fibres are protein structures that form early in mitosis or cell division. They consist of microtubules that originate from the centrioles, two wheel-shaped bodies located in the centromere area of the cell.

C = Chromosomes - Thread-like structure of nucleic acids and protein found in the nucleus of most living cells. These carry genetic information in the form of genes.

Hence option C is the correct answer.

Malnutrition is a condition that results from eating a diet in which nutrients are not enough or are too much such that it causes health problems. It is often called undernutrition.

Undernourishment is most frequently due to not having enough high-quality food available to eat. This is related to high food prices and poverty. Undernutrition is sometimes used as a synonym for protein-energy malnutrition (PEM). Undernutrition includes stunted growth (stunting), wasting, and deficiencies of essential vitamins and minerals.

On an average, a human cell spends 24 hours of time to divide once, with the time span of phases as:

d. G₁-phase - 10 hrs (i),

c. S-phase - 9 hrs (ii),

b. G₂-phase - 4 hrs (iii) and

a. M-phase - 1 hr (iv).

Therefore, the correct option is B. - i).→ d., ii).→ c., iii).→ b., iv). → a.

Based on key changes and the image given, this stage of Mitosis is Anaphase.

[Anaphase (from the Greek ἀνά, "up" and φάσις, "stage"), is the stage of mitosis after the process of metaphase, when replicated chromosomes are split and the newly-copied chromosomes (daughter chromatids) are moved to opposite poles of the cell.]

Hence option B is the correct answer.

Biomechatronics is an applied interdisciplinary science that aims to integrate mechanical elements, electronics and parts of biological organisms. Biomechatronics includes the aspects of biology, mechanics, and electronics. It also encompasses the fields of robotics and neuroscience. The goal of this science is to make devices that interact with human muscle, skeleton, and nervous systems. The end result is that the devices will help with human motor control that was lost or impaired by trauma, disease or birth defects.

Hence option B is the correct answer.

The process of duplication of chromosomes or DNA content begins in S phase and is regarded as the replication stage.

Hence option D is the correct answer.

Every cell divides once to produce 2 daughter cells in 1 minute. If in 20 mins it could fill \(\frac{1}{8 t h}\) of the volume of a flask, then, \(\Rightarrow \ln 21^{s t} \min =\frac{1}{8} \times 2=\frac{1}{4}\)

\(\Rightarrow \ln 22^{n d} \min =\frac{1}{4} \times 2=\frac{1}{2},\) and

\(\Rightarrow \ln 23^{r d} \min =\frac{1}{2} \times 2=1,\) or the entire.

So the time taken by the cells to fill the entire flask would be 23 mins.

Hence option D is the correct answer.

Sucralose is an artificial sweetener. The majority of ingested sucralose is not broken down by the body and therefore it is non-caloric. Sucralose is approximately 600 times as sweet as sucrose (table sugar), twice as sweet as saccharin, and 3 times as sweet as aspartame. It is stable under heat and over a broad range of pH conditions. Therefore, it can be used in baking or in products that require a longer shelf life. The commercial success of sucralose-based products stems from its favorable comparison to other low-calorie sweeteners in terms of taste, stability, and safety.It is used because it is a no-calorie sweetener, and does not promote dental cavities, is safe for consumption by diabetics, and does not affect insulin levels.

Hence option C is the correct answer.

Interphase refers to all stages of the cell cycle other than the mitotic phase. During interphase, cellular organelles double in number, the DNA replicates, and protein synthesis occurs. The chromosomes are not visible and the DNA appears as uncoiled chromatin. DNA synthesis takes place during the S phase of interphase. S phase (synthesis phase) is the part of the cell cycle in which DNA is replicated, occurring between G1 phase and G2 phase. Precise and accurate DNA replication is necessary to prevent genetic abnormalities which often lead to cell death or disease.

Hence option A is the correct answer.

In order for a plant to grow and thrive, it needs a number of different chemical elements. The most important are:

Carbon, hydrogen and oxygen – Available from air and water and therefore in plentiful supply Nitrogen, phosphorus, potassium (a.k.a. potash) – The three macro nutrients and the three elements you find in most packaged fertilizers

Sulfur, calcium, and magnesium – Secondary nutrients Boron, cobalt, copper, iron, manganese, molybdenum and zinc – Micro nutrients.

Hence option B is the correct answer.

Most of the essential micronutrients are almost exclusively stored in the husk, aleurone and embryo of rice, which are removed during the polishing process. Polishing of rice is required as the oil-rich aleurone layer turns the seed rancid upon storage and therefore making rice unsuitable for consumption. Consequently, the rice endosperm that comprises the edible part of rice for humans lacks or contains only small amount of key micronutrients (e.g., iron, zinc, protein, provitamin A, and other vitamins) that are essential for a healthy diet. Considering the facts above and severity of widespread micronutrient malnutrition, iron biofortification in rice endosperm is a promising strategy to overcome iron deficiency effectively.

Hence option C is the correct answer.

In Biology, "Karyon" refers to the nucleus of the cell. So karyokinesis is the division of the nucleus during cell division.

Hence option C is the correct answer.

Based on key changes and the image given, this stage of Mitosis is Anaphase.

[Anaphase (from the Greek ἀνά, "up" and φάσις, "stage"), is the stage of mitosis after the process of metaphase, when replicated chromosomes are split and the newly-copied chromosomes (daughter chromatids) are moved to opposite poles of the cell.]

Hence option B is the correct answer.

Mitosis is the process of cell division wherein the chromosomes replicate and get equally distributed into two daughter cells. The chromosome number in each daughter cell is equal to that in the parent cell, i.e., diploid. Hence, mitosis is known as equational division. The chromosome number in each daughter cell is equal to that in the parent cell, i.e., diploid. Hence, mitosis is known as equational division.

Hence option D is the correct answer.

Spindle fibres are made up of Tubulin.

Spindle fibers form a protein structure that divides the genetic material in a cell. The spindle is necessary to equally divide the chromosomes in a parental cell into two daughter cells during both types of nuclear division: mitosis and meiosis. During mitosis, the spindle fibers are called the mitotic spindle. Spindle fibers are aggregates of microtubules that move chromosomes during cell division.