1.
Genes are found on:
Correct Answer
A. Chromosomes
Explanation
Genes are found on chromosomes, which are structures made of DNA that carry genetic information. Chromosomes are located in the nucleus of cells and contain many genes. Genes are segments of DNA that code for specific traits or characteristics. They are passed down from parents to offspring through the process of reproduction. Therefore, it is correct to say that genes are found on chromosomes.
2.
When two parent cells join together to form offspring it is:
Correct Answer
B. Sexual reproduction
Explanation
When two parent cells join together to form offspring, it is considered sexual reproduction. This process involves the fusion of gametes (reproductive cells) from two different individuals, resulting in genetic variation in the offspring. Asexual reproduction, on the other hand, involves the production of offspring from a single parent, without the involvement of gametes or genetic recombination. Meiosis is a type of cell division that occurs during sexual reproduction, where the number of chromosomes in the parent cells is halved to produce gametes.
3.
The reproduction of sex cells is called:
Correct Answer
meiosis
Explanation
Meiosis is the process of cell division that occurs in the reproductive organs to produce sex cells, such as sperm and eggs. During meiosis, the cells undergo two rounds of division, resulting in the formation of four haploid cells with half the number of chromosomes as the parent cell. This process is essential for sexual reproduction as it ensures genetic diversity in offspring by shuffling and recombining genetic material. Therefore, meiosis is the correct term to describe the reproduction of sex cells.
4.
The two types of sex cells are______________ and ______________
Correct Answer
sperm and egg
Explanation
The two types of sex cells are sperm and egg. Sperm is the male sex cell, produced in the testes, while egg is the female sex cell, produced in the ovaries. These sex cells are responsible for sexual reproduction, where the sperm fertilizes the egg to form a zygote, which eventually develops into a new organism. The combination of genetic material from both the sperm and egg contributes to the unique characteristics of the offspring.
5.
Female chromosomes are __________ and male chromosomes are _____________
Correct Answer
XX, XY
Explanation
Female chromosomes are represented by XX, while male chromosomes are represented by XY. This is due to the fact that females have two X chromosomes, one inherited from each parent, while males have one X chromosome inherited from the mother and one Y chromosome inherited from the father. The presence or absence of the Y chromosome determines the sex of an individual.
6.
A diagram that shows the occurrence of a trait over generations of a family is a Punnett Square.
Correct Answer
B. False
Explanation
A Punnett Square is actually a diagram used to predict the probability of traits being passed on to offspring in a particular crossbreeding scenario. It is not used to show the occurrence of a trait over generations of a family. Therefore, the statement is false.
7.
Chromosomes that have the same genes/structures are:
Correct Answer
B. Homologous chromosomes
Explanation
Homologous chromosomes are chromosomes that have the same genes and structures. They are similar in size, shape, and carry the same genetic information. These chromosomes are found in pairs, with one chromosome inherited from each parent. During meiosis, homologous chromosomes undergo crossing over, where genetic material is exchanged between them, leading to genetic variation. Homologous chromosomes play a crucial role in genetic inheritance and are responsible for the transmission of traits from one generation to the next.
8.
Each sex cell contains 23 pairs of chromosomes.
Correct Answer
B. False
Explanation
Each sex cell actually contains 23 individual chromosomes, not 23 pairs. Pairs of chromosomes are found in somatic cells, which are non-reproductive cells. Sex cells, such as sperm and eggs, contain only half the number of chromosomes found in somatic cells, allowing for the combination of genetic material during fertilization. Therefore, the statement that each sex cell contains 23 pairs of chromosomes is false.
9.
Only cells that produce sex cells carry out meiosis.
Correct Answer
A. True
Explanation
Meiosis is a specialized type of cell division that produces sex cells, such as eggs and sperm. These sex cells are also known as gametes. Other cells in the body, known as somatic cells, do not undergo meiosis. Instead, they undergo a different type of cell division called mitosis. Therefore, only cells that produce sex cells carry out meiosis, making the statement "Only cells that produce sex cells carry out meiosis" true.