Olympiad Test: Reaching The Age Of Adolescence - Free MCQ with solutions

The larynx, commonly known as the voice box, is located at the top of the neck in tetrapods. It plays a crucial role in:

• Breathing
• Sound production
• Protecting the trachea from food aspiration

The sound produced by the larynx varies based on the position of the tongue, lips, mouth, and pharynx. During swallowing, the tongue moves backward, causing a flap called the epiglottis to cover the laryngeal opening, preventing food from entering the airway.

In boys, the larynx grows larger during puberty, leading to noticeable changes in voice, often resulting in a deeper tone. This growth can cause temporary hoarseness as the muscles of the voice box adjust.

Explanation:

The correct answer is B: Female gamete.

Reasoning:

• Gametes are reproductive cells involved in sexual reproduction.
• There are two types of gametes: sperm (male) and eggs (female).
• Sperm is produced in the male reproductive system, specifically in the testes.
• Eggs, also known as ova or oocytes, are produced in the female reproductive system, specifically in the ovaries.
• During sexual reproduction, a sperm and an egg fuse in a process called fertilisation, forming a zygote that develops into an embryo.

Thus, based on the understanding of gametes and their roles, the correct answer is B: Female gamete.

Chromosomes in Human Cells:

• Chromosomes are thread-like structures in the nucleus of cells that carry genetic information.
• They consist of DNA and proteins, containing genes that influence an individual's traits.
• Humans have two types of chromosomes: autosomes and sex chromosomes.

Autosomes:

• Autosomes are non-sex chromosomes that determine most traits.
• There are 22 pairs of autosomes in a human cell.

Sex Chromosomes:

• Sex chromosomes determine an individual's sex.
• Humans have two sex chromosomes: X and Y.
• Females have two X chromosomes (XX), while males have one X and one Y chromosome (XY).

Total Number of Chromosomes:

• The total number of chromosomes in a human cell is the sum of autosomes and sex chromosomes.
• With 22 pairs of autosomes and one pair of sex chromosomes, there are a total of 23 pairs.
• Each pair consists of two chromosomes, one from each parent.

Therefore, the correct answer is A: 23.

Explanation:

Initially, girls grow faster than boys due to several factors:

• Hormonal Differences: Girls experience growth spurts earlier because of different hormone levels.
• Bone Growth: Girls' bones mature faster than boys' during puberty, contributing to their early growth.
• Puberty Timing: Girls typically enter puberty before boys, leading to significant growth.
• Genetic Factors: Genetics can influence growth rates, with girls often inheriting genes for faster growth.

While girls may initially grow faster, boys usually catch up and often surpass girls in height during adolescence.

The correct answer is 8 to 14 years. According to the NCERT Science Class 8 textbook, puberty in females can begin any time between the ages of 8 and 14 years. While it most commonly starts between 10 and 12 years, it is normal for some girls to begin as early as 8 or as late as 14 years. This wider age range covers the natural variation in the onset of puberty among individuals. Therefore, option a) 8 to 14 years best represents the typical age range for the onset of puberty in females.

The correct answer is C as the male hormone is Testosterone. This hormone is the primary sex hormone and an anabolic steroid in males. It plays a crucial role in:

• Development of male reproductive tissues.
• Growth of facial hair and deepening of the voice.
• Regulating other physical changes during puberty.

In summary, testosterone is essential for the physical and reproductive development in males.

Chemicals secreted by endocrine glands are not called enzymes. The correct answer is False.

Explanation:

• Endocrine glands produce hormones, which are different from enzymes. Hormones are released into the bloodstream and act as messengers to regulate various bodily functions.
• Enzymes are proteins that act as catalysts in biochemical reactions, speeding up chemical processes in the body. They are not secreted by endocrine glands.
• Enzymes are produced by various organs, such as the pancreas, liver, and stomach.
• Endocrine glands include the pituitary gland, thyroid gland, and adrenal glands, each secreting specific hormones that regulate different functions.
• Hormones are crucial for maintaining homeostasis, growth, metabolism, reproduction, and other physiological processes.
• It is essential to differentiate between hormones and enzymes, as they serve different functions in the body.

Therefore, the statement that the chemicals secreted by endocrine glands are called enzymes is false.

Insulin is a hormone produced by the pancreas, not the pituitary gland. It plays a crucial role in regulating blood sugar levels.

The pancreas releases insulin through the following process:

• Insulin is produced by beta cells in the islets of Langerhans.
• It is released in response to food intake.

Therefore, the statement that insulin is produced by the pituitary gland is false.

Explanation:

Diabetes:

• Diabetes is a chronic condition marked by high blood sugar levels.
• It arises when the body cannot effectively use or produce enough insulin, a hormone that controls blood sugar levels.

Insulin and Pancreas:

• Insulin is made by the pancreas, located in the abdomen.
• The pancreas releases insulin when blood sugar levels rise.
• Insulin helps move glucose from the blood into cells for energy.
• In diabetes, there is either not enough insulin produced or the body does not respond to it.

Types of Diabetes:

• Type 1 Diabetes:
  • The immune system attacks and destroys insulin-producing cells in the pancreas.
  • This leads to little or no insulin production.
  • Type 1 diabetes is often diagnosed in childhood or adolescence.
• Type 2 Diabetes:
  • This is the most common type of diabetes.
  • It occurs when the body becomes resistant to insulin or does not produce enough.
  • Factors like an unhealthy diet, lack of exercise, and obesity can lead to Type 2 diabetes.
  • It can develop at any age but is more common in adults.

Conclusion:

• Diabetes is indeed caused by insufficient insulin secretion or a lack of response to insulin.
• This can result from various factors, including autoimmune destruction of insulin-producing cells (Type 1) or insulin resistance (Type 2).
• Thus, the statement "Diabetes is caused by less secretion of insulin by the pancreas" is generally accurate but does not cover all aspects of diabetes.

Estrogen is a male hormone - False

• Estrogen is primarily a female hormone, though it is found in both males and females in varying amounts.

• It plays a key role in the development and regulation of the female reproductive system and secondary sexual characteristics.

• In males, the main hormone is testosterone, which regulates the male reproductive system and secondary sexual traits.

• Estrogen is crucial for the menstrual cycle, pregnancy, and the development of female characteristics like breast growth and hip widening.

• Additionally, it helps regulate bone density, cholesterol levels, and supports cardiovascular health.

• In males, estrogen is present in smaller quantities, mainly produced in the testes and adrenal glands.

• An imbalance in estrogen levels in males can lead to health issues such as gynecomastia (enlarged breasts), reduced libido, and infertility.

• Thus, it is incorrect to classify estrogen as a male hormone; it is primarily associated with females but is also present in males.

Puberty typically occurs in girls between the ages of 10 and 14. In contrast, boys generally experience puberty later, between 12 and 16.

The period of life when the body undergoes significant changes leading to reproductive maturity is known as adolescence. This phase usually begins around the age of 11 and can last until 18 or 19 years old.

• Adolescence is marked by various physical changes.
• These changes include growth spurts and the development of secondary sexual characteristics.
• For girls, this may involve breast development and the start of menstrual cycles.
• Boys may notice facial hair growth and a deeper voice.

It is important to note that the onset of puberty varies for each individual, and some may experience these changes earlier or later than their peers.

Explanation:

• Gametes, such as sperm and eggs, carry genetic information from parents to offspring.

• Sperm cells, produced by males, contain either an X or a Y chromosome.

• The X chromosome determines female traits, while the Y chromosome determines male traits.

• Thus, some sperm cells have an X chromosome, and others have a Y chromosome.

• If a sperm with an X chromosome fertilises an egg, the offspring will be female (XX).

• If a sperm with a Y chromosome fertilises an egg, the offspring will be male (XY).

• This process is how the biological sex of an individual is determined.

• The chance of fertilisation by either an X or Y sperm is approximately equal, resulting in about a 50% chance of having a male or female offspring.

• Out of the 23 pairs of chromosomes in humans, only one pair is called sex chromosomes.
• The 23rd pair determines sex: XX for females and XY for males.
•  The other 22 pairs are called autosomes.
• Therefore, the statement that two pairs are sex chromosomes is incorrect.

 So, the correct answer is B: False.