Correct Answer: D. 75°W

Correct Answer: A. primary production

Correct Answer: A) saprophytic nutrition involves feeding on a soluble organic material from inorganic substances

Explanation

This question is asking us to identify the statement that is not true among the given options. Option A states that saprophytic nutrition involves feeding on a soluble organic material from inorganic substances, and this is correct. Saprophytic nutrition is a type of nutrition in which an organism feeds on dead and decaying organic matter, releasing enzymes to break down the matter into smaller soluble organic compounds that can be absorbed. Option B states that symbiosis is a nutritional relationship in which both organisms involved derive benefit, and this is also true. Symbiosis is a type of relationship in which two organisms of different species live in close association, and both organisms benefit from the interaction. Option C states that a parasite causes injuries to its host in the course of getting its food, and this is also true. Parasites are organisms that live in or on another organism, known as the host, and obtain their food from the host. In the process, they often cause harm or injury to the host. Option D states that holozoic mode of nutrition can be seen in animals, carnivorous plants, and some protists, and this is also true. Holozoic nutrition is a type of nutrition in which an organism ingests solid food and then digests it internally. This mode of nutrition is seen in animals, carnivorous plants, and some protists. Therefore, the statement that is not true among the given options is Option A, as it is actually a true statement.

Explanation

(a) Sexual reproduction is the fusion or joining of male and female gametes or nuclei from different individual to form a zygote which later develops into an embryo or organism.

(b) Functions of the placenta:

(i) The placenta attaches the foetus to the uterine wall of the mother.

(ii) It filters out urea or nitrogenous waste of baby's blood and transfers it to the.mother's blood and kidneys.

(iii) It absorbs digested food from the mother's blood and passes it on to foetus by diffusion.

(iv) The placenta allows passage of ingredients or antibodies that protect the developing foetus against infection.

(v) It exchanges CO from the foetus' blood for oxygen from the mother's blood.

(vi) It prevents the mixing of foetal-and mother's blood.

(vii) The placenta produces the hormones that prevent ovulation and menstruation during pregnancy.

(viii) It prevents passage of some pathogens from mother to foetus.

(ix) It converts glucose to fructose.

(x) It allows the passage of drugs or vaccines and alcohol from mother to foetus.

Functions of the umbilical cord:

(i) The umbilical cord attaches the foetus to the placenta.

(ii) The vein in the umbilical cord transports digested food and oxygenated blood from the placenta to the foetus.

(iii) The artery transports waste metabolic products or excretory products and deoxygenated blood from the foetus to the placenta

(vii) It suspends foetus in the amniotic cavity.

(c) Types of placentation in flowering plants: (i) Axile (tomato) (ii) Marginal (legumes) (iii) Parietal (pawpaw) (iv) Free-central (orange) (v) Basal (vi) Central (vii) Pendulous (viii) Superficial

(d) The conditions necessary for seed germination include; (i) viability of seed (ii) adequate supply cif moisture or water (iii) suitable temperature i.e warmth (iv) adequate supply of air e.g. oxygen (v) suitable soil pH.

Correct Answer: D. Presence of starch grain

Correct Answer: C) NO₂

Explanation

When copper metal is added to concentrated trioxonitrate (v) acid, it dissolves and releases a gas. The question is asking which gas is released. The options are CO₂, SO₂, NO₂ and CO.

CO₂ is carbon dioxide, which is a gas formed from carbon and oxygen. SO₂ is sulfur dioxide, which is a gas formed from sulfur and oxygen. CO is carbon monoxide, which is a gas formed from carbon and oxygen.

The correct answer is option C, NO₂, which is nitrogen dioxide. Nitrogen dioxide is a reddish-brown gas that is formed when nitrogen and oxygen react at high temperatures, and it is released when copper metal dissolves in concentrated trioxonitrate (v) acid.

It is important for students to understand the properties of acids and bases, how they react with metals, and the gases that are produced when some metals react with acids. This knowledge is important in understanding the chemical reactions that occur in the environment and in industrial processes.

For more information, please see the recommended textbooks.

Correct Answer: C. impermeable

Correct Answer: C. communism

Correct Answer: B. 12.6 years

Explanation

\(Mean = \frac{\text{sum of ages}}{\text{no of pupils}}\)

Let the sum of the ages of the 15 pupils be x and the sum of the 16 pupils be y.

\(\frac{x}{15} = 14.2 \implies x = 14.2 \times 15 = 213\)

\(\frac{y}{16} = 14.1 \implies y = 14.1 \times 16 = 225.6\)

\(\text{Age of new pupil} = 225.6 - 213 = 12.6\)

Correct Answer: A. I and III only