Olympiad Test: Reaching The Age Of Adolescence - Class 8 MCQ

The larynx  commonly called the voice box, is an organ in the top of the neck of tetrapods involved in breathing, producing sound, and protecting the trachea against food aspiration. It becomes a different sound based on the position of the tongue, lips, mouth, and pharynx. When swallowing, the backward motion of the tongue forces part of the larynx called the epiglottis to cover up the opening to the larynx, also called the laryngeal opening.

Explanation:
The correct answer is B: Female gamete.
Reasoning:
To determine the correct answer, it is important to understand the concept of gametes and their roles in reproduction.
- Gametes are reproductive cells that are involved in sexual reproduction.
- In most animals, including humans, there are two types of gametes: sperm and eggs.
- Sperm is the male gamete, while eggs (also known as ova or oocytes) are the female gametes.
- Sperm is produced by the male reproductive system, specifically in the testes.
- Eggs, on the other hand, are produced by the female reproductive system, specifically in the ovaries.
- During sexual reproduction, a sperm and an egg fuse together in a process called fertilization, resulting in the formation of a zygote which develops into an embryo.
Therefore, based on the understanding of gametes and their roles, the correct answer is B: Female gamete.

Thyroxine is produced by the thyroid gland.
The thyroid gland is a butterfly-shaped gland located in the front of the neck. It is responsible for producing and releasing thyroid hormones, including thyroxine (also known as T4). Thyroxine is an important hormone that plays a crucial role in regulating metabolism and growth.
Key points:
- Thyroxine is produced by the thyroid gland.
- The thyroid gland is located in the front of the neck.
- It is responsible for regulating metabolism and growth.
- Thyroxine is a crucial hormone for the body's overall functioning.
- The production and release of thyroxine are regulated by the pituitary gland, which produces thyroid-stimulating hormone (TSH) to stimulate the thyroid gland.
- The adrenal gland produces other hormones, such as cortisol and adrenaline, but not thyroxine.
- The testes in males are responsible for producing testosterone, not thyroxine.
In summary, thyroxine is produced by the thyroid gland, and it plays a vital role in regulating metabolism and growth in the body.

To determine the correct answer, we need to understand the concept of chromosomes in human cells.
Chromosomes in Human Cells:
- Chromosomes are thread-like structures found in the nucleus of cells that carry genetic information.
- They are composed of DNA and proteins and contain genes that determine the characteristics of an individual.
- Humans have two types of chromosomes: autosomes and sex chromosomes.
Autosomes:
- Autosomes are non-sex chromosomes that determine the majority of an individual's traits.
- There are 22 pairs of autosomes in a human cell.
Sex Chromosomes:
- Sex chromosomes determine the sex of an individual.
- In humans, there are 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 in Human Cells:
- The total number of chromosomes in a human cell is the sum of autosomes and sex chromosomes.
- Since there are 22 pairs of autosomes and one pair of sex chromosomes, the total number of chromosomes is 23 pairs.
- Each pair consists of two chromosomes, one inherited from each parent.
- Therefore, the correct answer is A: 23.
In conclusion, there are 23 pairs of chromosomes in a human cell.

Explanation:

Girls initially grow faster than boys due to several factors such as:

• Hormonal Differences: Girls tend to experience growth spurts earlier than boys due to differences in hormone levels.


• Bone Growth: Girls' bones typically mature faster than boys during puberty, which contributes to their initial growth spurt.


• Puberty Timing: Girls usually enter puberty earlier than boys, and this period is associated with significant growth and development.


• Genetic Factors: Genetic factors can also play a role in the rate of growth, with girls often inheriting genes that contribute to faster growth.

It is important to note that while girls may initially grow faster than boys, boys eventually catch up and typically surpass girls in height during adolescence.

Period of maturity of reproductive organs
The period of maturity of reproductive organs is called adolescence period. During this time, the reproductive organs undergo significant development and become capable of sexual reproduction. Here are the key points to explain this in detail:
1. Adolescence period:
- This is the stage of life between childhood and adulthood.
- It is characterized by rapid physical, psychological, and emotional changes.
- Generally, it starts around the age of 10-12 in girls and 12-14 in boys.
- During this period, the reproductive organs reach their full development and become functional.
2. Development of reproductive organs:
- In girls, the reproductive organs, including the uterus, ovaries, and fallopian tubes, undergo development and maturation.
- The onset of menstruation, or the first menstrual period, marks the beginning of the ability to conceive.
- Menstruation is the shedding of the uterine lining and the release of an egg from the ovaries.
- In boys, the testes enlarge and begin to produce sperm, marking the onset of fertility.
3. Physical and hormonal changes:
- Along with the development of reproductive organs, adolescence is also characterized by secondary sexual characteristics.
- Girls experience breast development, widening of hips, and the growth of pubic and underarm hair.
- Boys undergo voice deepening, growth of facial and body hair, and an increase in muscle mass.
- Hormones such as estrogen and testosterone play a crucial role in these changes.
4. Importance of adolescence period:
- The adolescence period is essential for the continuation of the human species through reproduction.
- It is a critical time for sexual and reproductive health education to ensure safe and responsible behavior.
- Adolescents need support and guidance to navigate the physical and emotional changes they experience.
In conclusion, the period of maturity of reproductive organs is called the adolescence period. It is a time of significant physical and hormonal changes, marking the development and functionality of the reproductive system.

Explanation:
Fertilisation is the process by which a sperm cell fuses with an egg cell, resulting in the formation of a zygote. This process is essential for sexual reproduction in many organisms, including humans.
Here is a detailed explanation of the options provided:
A. To produce sperms:
- Sperm production, also known as spermatogenesis, occurs in the testes of male organisms.
- Spermatogenesis involves the division and differentiation of germ cells to produce mature sperm cells.
- While sperm production is a part of the reproductive process, it is not the sole purpose of fertilisation.
B. To produce eggs:
- Egg production, also known as oogenesis, occurs in the ovaries of female organisms.
- Oogenesis involves the development and maturation of egg cells.
- While egg production is a part of the reproductive process, it is not the sole purpose of fertilisation.
C. Fusion of sperms and eggs:
- Fertilisation involves the fusion of a sperm cell (carrying genetic material from the male) with an egg cell (carrying genetic material from the female).
- This fusion leads to the formation of a zygote, which is the first cell of a new individual.
- Fertilisation is the crucial step that allows for the combination of genetic material from both parents, resulting in genetic diversity.
D. All of these:
- The correct answer is option C, "Fusion of sperms and eggs."
- Fertilisation involves both the production of sperm and eggs, as well as their fusion to form a zygote.
- Therefore, option D is the most accurate answer.
In conclusion, fertilisation is the process of the fusion of sperm and egg cells, leading to the formation of a zygote. While the production of sperm and eggs is a part of the reproductive process, fertilisation is the specific event where genetic material from both parents combines to create a new individual.

The correct answer is A as Puberty age in females is 10 to 12 years

Stoppage of Menstruation: Menopause
Menopause is the correct answer choice for the stoppage of menstruation. Here's a detailed explanation:
Definition:
- Menopause refers to the natural biological process in women when they stop having menstrual periods permanently.
- It marks the end of the reproductive years and typically occurs between the ages of 45 and 55.
Key Points:
- Menarche: The term "menarche" refers to the onset of menstruation in girls, usually around the age of 12-14.
- Puberty: Puberty is a stage of development in which a person becomes capable of sexual reproduction. It involves various physical changes, including the onset of menstruation in girls.
- Adolescence: Adolescence is the transitional period between childhood and adulthood, typically characterized by puberty and the associated physical, emotional, and social changes.
Explanation:
- Menarche and puberty are related to the beginning of menstruation and the development of reproductive capabilities in girls.
- Menopause, on the other hand, refers to the cessation of menstruation, marking the end of a woman's reproductive years.
- During menopause, the ovaries stop releasing eggs and produce lower levels of hormones, leading to the absence of menstrual periods.
Conclusion:
- Menopause is the correct answer for the stoppage of menstruation.
- Menarche, puberty, and adolescence are all related to the onset and development of menstruation, but not the cessation of it.

The correct answer is C as the male hormone is Testosterone which  is the primary sex hormone and anabolic steroid in males. In male humans, testosterone plays a key role in the development of male reproductive tissues.

False: The stomach is not called the voice box.
Explanation:
- The voice box is actually another term for the larynx, which is an organ located in the throat.
- The larynx plays a crucial role in producing sound and allowing us to speak.
- On the other hand, the stomach is part of the digestive system and is responsible for breaking down food and absorbing nutrients.
- While both the voice box and the stomach are important organs, they serve different functions in the body.
- It is important to use the correct terminology to avoid confusion and ensure clear communication in medical and anatomical contexts.

Boys have enlarged and well developed Adam's apple.

False.

Explanation:

An Adam's apple is a prominent laryngeal prominence that is more visible in males due to the effects of testosterone during puberty. However, it is not accurate to say that all boys have enlarged and well-developed Adam's apples. The size and visibility of the Adam's apple can vary among individuals, and it is not solely determined by gender.

Here are some key points to consider:

• The Adam's apple, also known as the thyroid cartilage, is a part of the larynx.


• During puberty, the larynx grows in size in both boys and girls.


• However, due to hormonal differences, the larynx typically grows more in boys, resulting in a more visible Adam's apple.


• It is important to note that not all boys will have a pronounced Adam's apple, as its size and visibility can vary among individuals.


• Factors such as genetics, body composition, and hormonal levels can influence the size and visibility of the Adam's apple.


• It is also worth mentioning that some girls may have a visible Adam's apple, although it is generally less prominent compared to males.

In conclusion, while it is true that males generally have a more visible Adam's apple due to the effects of testosterone during puberty, it is not accurate to say that all boys have enlarged and well-developed Adam's apples. The size and visibility of the Adam's apple can vary among individuals and are influenced by various factors.

Chemicals secreted by endocrine glands are not called enzymes. The correct answer is False.
Explanation:
- Endocrine glands secrete hormones, not enzymes. Hormones are chemicals that are released into the bloodstream and act as messengers to regulate various bodily functions.
- Enzymes, on the other hand, are proteins that act as catalysts in biochemical reactions. They help speed up chemical reactions in the body but are not secreted by endocrine glands.
- Enzymes are produced by various cells and organs throughout the body, including the pancreas, liver, and stomach.
- Endocrine glands include the pituitary gland, thyroid gland, adrenal glands, and others. Each gland secretes specific hormones that regulate different functions in the body.
- Hormones play a crucial role in maintaining homeostasis, growth, metabolism, reproduction, and other physiological processes.
- It is important to distinguish between hormones and enzymes as they have different functions and mechanisms of action in the body.
- Therefore, the statement that the chemicals secreted by endocrine glands are called enzymes is false.

The most important harmone that the pancreas produces is insulin. Insulin is released by the beta cells in the islets of Langerhans in response to food.
So, the given statement is false.

Explanation:
Chromosomes in human cells:
- Chromosomes are thread-like structures located in the nucleus of a cell.
- They carry genetic information in the form of DNA.
- Humans have 23 pairs of chromosomes in total.
Number of chromosomes:
- Each pair of chromosomes consists of one chromosome from the mother and one from the father.
- So, in total, there are 46 individual chromosomes in a human cell (23 pairs).
Therefore, the statement that there are 23 pairs of chromosomes in the nuclei of human cells is true.

Explanation:
Diabetes:
- Diabetes is a chronic disease characterized by high blood sugar levels.
- It occurs when the body cannot effectively use or produce enough insulin, a hormone that regulates blood sugar levels.
Insulin and Pancreas:
- Insulin is produced by the pancreas, an organ located in the abdomen.
- The pancreas is responsible for the secretion of insulin in response to high blood sugar levels.
- Insulin helps transport glucose (sugar) from the bloodstream into cells, where it is used for energy.
- In diabetes, there is either an insufficient production of insulin or the body becomes resistant to its effects.
Types of Diabetes:
1. Type 1 Diabetes:
- In Type 1 diabetes, the immune system mistakenly attacks and destroys the insulin-producing cells in the pancreas.
- This results in little to no insulin production.
- Type 1 diabetes is usually diagnosed in childhood or adolescence.
2. Type 2 Diabetes:
- Type 2 diabetes is the most common form of diabetes.
- It occurs when the body becomes resistant to insulin or does not produce enough insulin to maintain normal blood sugar levels.
- Lifestyle factors such as unhealthy diet, lack of physical activity, and obesity contribute to the development of type 2 diabetes.
- Type 2 diabetes can develop at any age, but it is more common in adults.
Conclusion:
- While it is true that diabetes is caused by an insufficient secretion of insulin or a lack of response to insulin, it is important to note that this can be due to various factors such as autoimmune destruction of insulin-producing cells (Type 1 diabetes) or insulin resistance (Type 2 diabetes).
- Therefore, the statement "Diabetes is caused by less secretion of insulin by the pancreas" is generally true, but it does not encompass all the complexities and factors involved in the development of diabetes.

Estrogen is a male hormone - False
- Estrogen is actually a female hormone, although it is present in both males and females, but in different quantities.
- Estrogen is primarily responsible for the development and regulation of the female reproductive system and secondary sexual characteristics in females.
- In males, testosterone is the predominant hormone responsible for the development and regulation of the male reproductive system and secondary sexual characteristics.
- Estrogen plays a crucial role in the menstrual cycle, pregnancy, and the development of female secondary sexual characteristics like breast development and widening of hips.
- Estrogen also has various other functions in the body, including regulating bone density, cholesterol levels, and maintaining cardiovascular health.
- In males, estrogen is present in smaller amounts and is produced primarily in the testes and adrenal glands.
- The imbalance of estrogen levels in males can lead to health issues such as gynecomastia (enlarged breasts), decreased libido, and infertility.
- Therefore, it is incorrect to say that estrogen is a male hormone. It is a hormone primarily associated with females, but also present in males in smaller quantities.

Puberty usually occurs in girls between the ages of 10-14  , while in boys it generally occurs later, between the ages of 12-16.

Explanation:
- Gametes, such as sperm and eggs, are responsible for carrying genetic information from parents to offspring.
- Sperm cells are produced by males and contain either an X or a Y chromosome.
- The X chromosome is responsible for determining female traits, while the Y chromosome is responsible for determining male traits.
- Therefore, some sperm cells have an X chromosome, and some have a Y chromosome.
- When a sperm with an X chromosome fertilizes an egg, the resulting offspring will be female (XX). On the other hand, when a sperm with a Y chromosome fertilizes an egg, the resulting offspring will be male (XY).
- This is the basis for the determination of the biological sex of an individual.
- It is important to note that the probability of fertilization by either an X or a Y sperm is approximately equal, resulting in an approximate 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.