Question 1

Sasha's 23rd chromosome pair contains two X chromosomes.This indicates that Sasha:

Accepted Answer

Females typically have two X chromosomes, while males have one X and one Y chromosome. Therefore, a person with two X chromosomes is likely to be female. Down syndrome and fragile X syndrome are genetic disorders that are not determined by the sex chromosomes.

Question 2

During the process of _____,the cell's nucleus-including the chromosomes-duplicates itself and the cell divides resulting in the formation of two cells.

Accepted Answer

Mitosis is the process of cell division in which the nucleus of a cell duplicates itself and divides, resulting in the formation of two identical daughter cells. This process occurs in all eukaryotic cells and is essential for growth, development, and repair of tissues. Meiosis, on the other hand, is a specialized type of cell division that only occurs in the formation of gametes (egg and sperm cells) and results in the production of four genetically diverse daughter cells. Osmosis is the diffusion of water molecules through a selectively permeable membrane, and fertilization is the fusion of egg and sperm cells to form a zygote.

Question 3

Jule's 23rd chromosome pair consists of an X chromosome and a Y chromosome.This indicates that Jule:

Accepted Answer

The presence of an X and Y chromosome pair indicates that Jule is male. Females have two X chromosomes, while males have one X and one Y chromosome. Down syndrome is a genetic disorder that occurs when there is an extra copy of chromosome 21, and XYY syndrome is a genetic condition where males have an extra Y chromosome.

Question 4

What are gametes?

Accepted Answer

Gametes are reproductive cells, also known as sex cells. They are specialized cells that carry half the genetic information needed to form a complete organism. In humans, gametes are eggs and sperm.

Question 5

A cell that contains 23 pairs of chromosomes,divides by mitosis to form two new cells.How many pairs of chromosomes does each new cell contain?

Accepted Answer

Mitosis produces two identical daughter cells, which means that both daughter cells will contain the same number of chromosomes as the parent cell. Therefore, each new cell will contain 23 pairs of chromosomes, just like the parent cell.

Question 6

During fertilization,an egg and a sperm fuse to create a single cell called a _____.

Accepted Answer

During fertilization, the sperm and egg combine to form a single cell called a zygote. The other choices are not correct as blastocyst is the name for the stage of development after the zygote undergoes multiple cell divisions, fetus refers to the later stage of development when major organs and systems have formed, and gamete refers to the sperm or egg cell before they fuse during fertilization.

Question 7

_____ genes are those that make the individual more vulnerable to specific diseases or acceleration of aging.

Accepted Answer

Susceptibility genes are those that make an individual more vulnerable to specific diseases or conditions. These genes may increase an individual's risk for developing a disease, but it does not necessarily mean that the disease will develop.

Question 8

During _____,a cell of the testes in men or ovaries in women duplicates its chromosomes and then divides twice,thus forming four cells,each of which has only half the genetic material of the parent cell.

Accepted Answer

Meiosis is the process by which cells in the testes of men or ovaries in women duplicate their chromosomes and then divide twice, resulting in the formation of four cells, each with only half of the genetic material of the parent cell. This reduction in genetic material is important for sexual reproduction, as it ensures that each offspring receives a unique combination of genetic material from both parents.

Question 9

Combining the genes of two parents in offspring increases _____ in the population,which is valuable for a species because it provides more characteristics for natural selection to operate on.

Accepted Answer

Combining the genes of two parents in offspring increases genetic variability in the population, which is valuable for a species because it provides more characteristics for natural selection to operate on. This increases the chances of survival and adaptation to changing environments. Option A and B are incorrect as the number of males or females is not directly affected by combining genes. Option D is incorrect because genetic uniformity can limit the ability of a species to adapt to new circumstances, making it more vulnerable to extinction.

Question 10

A cell that contains 46 chromosomes arranged in 23 pairs undergoes the process of _____ to produce two new cells,each containing the same DNA as the original cell,arranged in the same 23 pairs of chromosomes.

Accepted Answer

Mitosis is the process by which a cell divides to produce two new cells, each with the same number and arrangement of chromosomes as the original cell.

Question 11

_____ is a stage in reproduction whereby an egg and a sperm fuse to create a single cell.

Accepted Answer

Fertilization is the process whereby an egg and a sperm fuse to form a single cell, called a zygote. This marks the beginning of embryonic development.

Question 12

Which of the following is true of mitosis?

Accepted Answer

Mitosis is the process of cellular division that results in the formation of two identical daughter cells, each with the same number of chromosomes as the parent cell. In humans, this means that mitosis results in the formation of new cells with 23 pairs of chromosomes. Option A is incorrect because the formation of sperm and egg cells occurs through meiosis, not mitosis. Option B and D are also incorrect because mitosis only results in the formation of two new cells, not four or three.

Question 13

Melody and Harmony are identical twins.This means that they developed from:

Accepted Answer

Identical twins develop from a single egg that was fertilized by a single sperm, which then splits into two embryos.

Question 14

_____ develop from a single zygote that splits into two genetically matching replicas,each of which becomes a person.

Accepted Answer

Identical twins develop from a single zygote that splits into two genetically matching replicas, each of which becomes a person. Triplets, quadruplets, or higher-order multiples can also develop this way, but the question specifically asks for a single answer option. Fraternal twins, on the other hand, develop from two separate zygotes that are fertilized by two separate sperm.

Question 15

A mistake by the cellular machinery,or damage from an environmental agent such as radiation,may produce a _____,which is a permanently altered segment of DNA.

Accepted Answer

A mistake in cellular machinery or environmental damage can lead to a permanent alteration in DNA, which is called a mutation. A susceptibility gene is a gene that increases the likelihood of developing a certain disease but does not necessarily involve DNA mutation. A vulnerability gene is not a commonly used term in genetics. A longevity gene is a gene associated with longer lifespan, but not necessarily involving DNA mutation.

Question 16

In human beings,by the end of meiosis,each egg or sperm has _____ chromosomes.

Accepted Answer

During meiosis, the number of chromosomes is halved resulting in the formation of haploid cells (cells with half the number of chromosomes as compared to the parent cell). In humans, the parent cell has 46 chromosomes arranged in 23 pairs. By the end of meiosis, each egg or sperm would have 23 chromosomes but they will be unpaired. Hence, the best answer is option B, which states that each egg or sperm has 23 unpaired chromosomes.

Question 17

Which of the following statements about the activity of genes is TRUE?

Accepted Answer

Events that occur inside of the cell, such as signaling pathways, can excite or inhibit genetic expression. This is why certain genes may only be turned on in certain cell types or under certain circumstances. Option A is incorrect because genes can actually work collaboratively to produce a particular trait or protein. Option B is incorrect because some genes code for multiple proteins through alternative splicing. Option C is incorrect because environmental factors, such as nutrition and stress, can impact genetic expression.

Question 18

Ethel is 50 years old but appears much more aged.Most of Ethel's relatives have not lived past the age of 60.Which of the following genes are responsible for the accelerated aging that is observed in Ethel and her family members?

Accepted Answer

The answer of Ethel is 50 years old but appears...

Question 19

Jerome and Tyrone are fraternal twins.This means that they developed from:

Accepted Answer

Fraternal twins are formed when two eggs are fertilized by two different sperms. As a result, they are genetically as similar as any siblings born at different times to the same parents.

Question 20

Except for the sperm and the egg,all cells in the human body have _____ chromosomes.

Accepted Answer

Except for the sperm and the egg cells, which have 23 chromosomes each, all other cells in the human body have 46 chromosomes.

Quiz 2: Biological Beginnings