Correct Answer: A. Water removed from oceans are Permanently lost

Correct Answer: C. C

Correct Answer: A) involve chemical transmission

Explanation

The question is asking about the similarities between the nervous and hormonal systems. The options are given as follows: involve chemical transmission, have widespread effects, shed chemicals into the bloodstream, and evoke rapid response to eliminate response. The correct answer is option A: involve chemical transmission. Both the nervous and hormonal systems use chemicals to transmit messages or signals throughout the body. In the nervous system, neurons use chemical messengers called neurotransmitters to send signals between themselves and to other cells, while in the hormonal system, glands secrete hormones into the bloodstream to carry signals to different parts of the body. While both systems involve chemical transmission, there are some differences between them. For example, the nervous system is faster and more specific in its responses, while the hormonal system is slower and more widespread in its effects. Additionally, the nervous system can respond to immediate changes in the environment, while the hormonal system is more involved in long-term regulation and maintenance of bodily functions. Overall, understanding the similarities and differences between the nervous and hormonal systems is important for understanding how the body communicates and regulates its various functions.

Correct Answer: D) Cerebrum

Explanation

The question is asking which part of the mammalian brain is responsible for the decision to run instead of walk. The given options are the cerebellum, medulla oblongata, cranial nerves, and cerebrum. To answer this question, we need to understand the functions of these brain parts. The cerebellum is responsible for coordination and balance, while the medulla oblongata controls involuntary functions such as breathing and heart rate. Cranial nerves are responsible for sensory and motor functions of the head and neck. The cerebrum is responsible for conscious thought, perception, and decision-making. Therefore, the correct answer is option D, cerebrum, as it is responsible for making decisions such as whether to run or walk. The cerebrum is the largest part of the brain and has two hemispheres, the left and right, which are responsible for different functions. The left hemisphere is responsible for logical thinking and language, while the right hemisphere is responsible for creativity and spatial awareness. In conclusion, the cerebrum is the part of the mammalian brain responsible for the decision to run rather than walk. It is important to note that the functions of the different parts of the brain are interconnected, and damage to one part can affect the functions of other parts.

Correct Answer: C. Chromosomes

Correct Answer: C. All the components of blood except plasma protein and cells

Correct Answer: B) Snail

Explanation

Schistosoma, also known as Bilharzia, is a type of parasite that causes a disease called schistosomiasis. In the life history of Schistosoma, there are two hosts involved: the definitive host and the intermediate host. The definitive host is usually a mammal like a human, while the intermediate host is usually a snail. The intermediate host is important because that is where the parasite undergoes asexual reproduction and develops into a stage that can infect the definitive host. In this case, the correct answer to the question is Option B: Snail. This is because the snail is the intermediate host in the life history of Schistosoma. Once the parasite has developed in the snail, it is released into the water where it can infect the definitive host, which is usually a human. To prevent schistosomiasis, it is important to avoid contact with contaminated freshwater sources where the snails may be living. This can be achieved by practicing good hygiene and avoiding activities like swimming or bathing in freshwater sources that may be contaminated with the parasite. To learn more about schistosomiasis and the life history of Schistosoma, please refer to the relevant sections in your Biology textbook.

Correct Answer: D. ll and lV only

Explanation

Pesticides that are sprayed on to fields and used to fumigate soil can give off chemicals called volatile organic compounds, which can react with other chemicals and form a pollutant called ground level ozone.

Sulfur dioxide (SO2) is a gaseous air pollutant composed of sulfur and oxygen. SO2 forms when sulfur-containing fuel such as coal, oil, or diesel is burned.

Correct Answer: C) meiosis

Explanation

The question is asking about the process that guarantees that the number of chromosomes in an organism remains constant from one generation to the next. The options are fission, fusion, meiosis, mitosis, and oogenesis. Of these options, the correct answer is meiosis. Meiosis is a type of cell division that occurs only in the reproductive cells of an organism, such as the sperm and the egg. During meiosis, the chromosome number is reduced by half, resulting in the production of haploid cells (cells with half the normal number of chromosomes). When the sperm and egg combine during fertilization, the resulting zygote has the normal number of chromosomes for that species. This process is necessary to ensure that the offspring of an organism have the correct number of chromosomes. If the number of chromosomes is not correct, the offspring may not develop properly and may not be able to survive. Fission and fusion are not related to the process of maintaining the correct chromosome number. Mitosis is a type of cell division that occurs in somatic (non-reproductive) cells and results in the production of two identical daughter cells. Oogenesis is the process of egg cell formation in females and is related to meiosis, but is not the correct answer to this question. In summary, the process that ensures that the chromosome number for each species of organism remains constant from generation to generation is meiosis.

Correct Answer:

Explanation

(a) Definition of tropic and nastic movements:

(i) Tropic movement is growth movement of plant organs in response to external unilateral or directional stimulus. Nastic movement is the movement of certain parts of plants in response to diffuse or non-directional stimulus.

(ii)

Experiment to show that auxins are produced in the apical cells of a shoot:

Aim:To show that auxins are produced in the apical cells of a shoot.

Material: 3 potted seedlings of maize labelled A, B and C; agar block, sharp knife/cutting instruments, mica sheet / aluminium foil/cover slip.

Methods:

(i) Cut tip of coleoptile/shoot in Ato serve as control

(ii) Leave decapitated shoot for about 48 hours

(iii) Select another potted seedling, B,.and cut off tip of coleoptile/shoot

(iv) Place the cut tip on an agar block for about 2 — 6 hours

(v) Place agar block on stump of the decapitated shoot and leave for about 48 hours

(vi) Select a third seedling, C, and cut off tip of the coleoptile

(vii) Place tip of the cut coleoptile on mica sheet for 2 — 6 hours

(viii)Place mica sheet on cut surface of decapitated shoot and leave for about 48 hours.

Observation: Growth ceased in decapitated shoot A, but when agar block was placed on stump of shoot B in which growth had stopped, growth resumed. When mica sheet was placed on stump of shoot C in which growth had stopped, growth did not take place (resume).

Conclusion: This shows that a chemical substance (auxin) produced at the tip, i.e., apical cell of the shoot is responsible for the growth of the shoot.

(c)(i) Names of plant hormones other than auxins are

• Gibberellic acid / Gibberellin
• 2, 4 - D 2, 4 - Dichlorophenozy acid
• cytokinis/kinins/kinetin
• abscisic acid/abscisin
• ethylene/ethene
• traumatin
• florigen
• dormin
• formin, etc.

(ii) Examples of tropisms are:

• geotropism
• hydrotropism
• thigmotropism/Haptrodropism
• photoropism
• stereotropism
• chemotropism
• thermotropism.