Genetics And DNA Quiz Grade 10 Science

The correct answer is Cytosine. In a base pair, C represents Cytosine, which is one of the four nucleotide bases found in DNA and RNA. Cytosine pairs with Guanine (G) in DNA and with Guanine (G) in RNA. It is responsible for carrying genetic information and plays a crucial role in the structure and function of nucleic acids.

DNA is found in all living things because it is the genetic material that carries the instructions for the development, functioning, and reproduction of organisms. DNA is present in the cells of all living organisms, including plants, animals, bacteria, and fungi. It serves as a blueprint for the traits and characteristics of an organism, and is passed down from one generation to the next through reproduction. Therefore, DNA is a universal feature of all living things.

The chances of an offspring being a boy or a girl are 50%. This is because the probability of having a boy is equal to the probability of having a girl. In human reproduction, the sex of the offspring is determined by the combination of the father's sperm (which carries either an X or Y chromosome) and the mother's egg (which carries an X chromosome). Since there are only two possible outcomes (boy or girl), and each outcome has an equal chance of occurring, the probability of having a boy or a girl is 50%.

A dominant gene is a type of gene that always shows itself, meaning its traits are expressed and override the traits of any recessive gene. This is because dominant genes have a stronger influence on the phenotype (observable characteristics) of an organism. In a pair of alleles, if one allele is dominant and the other is recessive, the dominant allele will determine the phenotype. Homozygous genes refer to having two identical alleles for a particular trait, which can be either dominant or recessive. Therefore, the correct answer is dominant gene.

This statement is false because recessive genes only show themselves when an individual has two copies of the recessive gene. If an individual has one dominant gene and one recessive gene, the dominant gene will be expressed, and the recessive gene will be hidden. Therefore, a recessive gene does not always show itself.

Genes for a trait that are hidden when the dominant gene is present are called recessive genes. When an individual has two copies of the recessive gene, one from each parent, the trait associated with the recessive gene is expressed. In contrast, if an individual has even just one copy of the dominant gene, the trait associated with the recessive gene will be masked or hidden. This is why recessive genes are only expressed when there are no dominant genes present.

Chromosomes are located inside the nucleus of a cell. The nucleus is a membrane-bound organelle that contains the genetic material of the cell, including the chromosomes. The chromosomes are thread-like structures made up of DNA and proteins, and they carry the genetic information necessary for the cell's functions and characteristics. The nucleus acts as the control center of the cell, regulating gene expression and coordinating cellular activities. Therefore, the correct answer is the nucleus.

The correct answer is 46 because human body cells, also known as somatic cells, are diploid, meaning they contain two sets of chromosomes. Each set consists of 23 chromosomes, one inherited from each parent, resulting in a total of 46 chromosomes in each human body cell. This is the normal chromosome count for humans, excluding sex cells (sperm and egg cells), which only contain 23 chromosomes.

Alleles are different versions or forms of the same gene. They can occur due to variations in the DNA sequence of a gene, resulting in different traits or characteristics. Each individual inherits two alleles for each gene, one from each parent. These alleles can be either dominant or recessive, determining the expression of a particular trait. Therefore, alleles play a crucial role in genetic diversity and inheritance patterns.

Male organisms have one X and one Y chromosome. This is because the sex determination in humans is based on the presence of these chromosomes. Females have two X chromosomes, while males have one X and one Y chromosome. The presence of the Y chromosome determines the development of male characteristics, such as the production of sperm and the development of male reproductive organs. The X chromosome carries various genes responsible for a wide range of traits, including both male and female characteristics.

DNA, or deoxyribonucleic acid, is the correct answer. DNA is a large molecule that is found in chromosomes and carries the genetic information of an organism. It is made up of a double helix structure consisting of nucleotides. RNA, on the other hand, is another type of nucleic acid that plays a role in protein synthesis. DEA and DVD are unrelated to the molecule contained in chromosomes.

A chart that shows the possible gene combinations is called a Punnett Square. A Punnett Square is a graphical representation used in genetics to predict the possible genotypes of offspring in a cross between two individuals. It is named after Reginald Punnett, who developed this method. The Punnett Square displays all the possible combinations of alleles from the parents and helps determine the probability of certain traits being inherited by the offspring.

Homozygous refers to having two of the same genes for a certain trait. It means that both alleles for a particular gene are identical, either both dominant or both recessive. This results in the individual expressing the trait consistently. Heterozygous, on the other hand, means having two different alleles for the same gene, one dominant and one recessive. Therefore, the correct answer is homozygous.

Heterozygous refers to the condition of having two different genes for a specific trait. This means that an individual inherits one gene from each parent, and these genes may have different variations or alleles. In contrast, homozygous individuals have two identical genes for a trait. Therefore, the correct answer is "having two genes for a trait that are different."

Molecules of DNA are composed of long chains of nucleotides. Nucleotides are the building blocks of DNA and consist of a sugar molecule (deoxyribose), a phosphate group, and a nitrogenous base (adenine, thymine, cytosine, or guanine). These nucleotides form a double helix structure through hydrogen bonding between the nitrogenous bases, creating the genetic code that carries the instructions for the development and functioning of living organisms.

A human body cell contains 23 pairs of chromosomes. Each pair consists of two chromosomes, one inherited from the mother and one from the father. These chromosomes carry genetic information that determines various traits and characteristics in an individual. The total number of chromosomes in a human body cell is 46, with 23 pairs.

Sperm cells and egg cells are examples of gametes because they are specialized reproductive cells that are involved in sexual reproduction. Gametes are formed through a process called meiosis, which is a type of cell division that reduces the number of chromosomes in the cells by half. This reduction in chromosome number is necessary for the fusion of gametes during fertilization to restore the full complement of chromosomes in the resulting offspring. Therefore, gametes are distinct from body cells, which are also known as somatic cells, and contain the full complement of chromosomes. DNA is present in all cells, including gametes, but it is not the defining characteristic of gametes.

Every DNA nucleotide contains a sugar, a phosphate group, and a nitrogen base is a true statement about the structure of DNA. DNA consists of two strands of nucleotides joined by hydrogen bonds, forming a double helix. The short strands of DNA are contained in chromosomes inside the nucleus of a cell. Therefore, the statement "DNA consists of one strand of nucleotides joined by hydrogen bonds" is incorrect.

When two Larkeys with solid fur mate, they both have the genotype Ff. The F allele represents solid fur, while the f allele represents spotted fur. Since both Larkeys have the dominant F allele, there is a high likelihood that their offspring will inherit the solid fur trait. Therefore, the most likely fur type for their offspring is solid.

In this scenario, if the trait for fur pattern on a dog is determined by the alleles f (solid fur) and F (spotted fur), a homozygous female with solid fur (ff) and a homozygous male with spotted fur (FF) would produce offspring with a genotype of Ff, which would have the phenotype of spotted fur. Therefore, the statement that there is a 25% chance of having offspring with solid fur is incorrect.

The given question states that a Larkey with red eyes (EE) mates with a Larkey with gray eyes (ee). The eye color in this scenario is determined by a single gene with two possible alleles, E for red eyes and e for gray eyes. Since the first Larkey is homozygous for red eyes (EE) and the second Larkey is homozygous for gray eyes (ee), all the offspring will inherit one E allele from the first parent and one e allele from the second parent, resulting in a genotype of Ee for all the offspring. Therefore, the correct answer is "none of the above" as there is a 0% chance of the offspring having gray eyes.

When a woman who is a carrier of colorblindness mates with a colorblind man, there is a 50% chance that their offspring will actually be colorblind. This is because colorblindness is a sex-linked genetic disorder that is carried on the X chromosome. The woman has two X chromosomes, one of which carries the colorblindness gene, while the man has only one X chromosome, which carries the colorblindness gene. If the offspring inherits the colorblindness gene from either the mother or the father, they will be colorblind. Therefore, the chance of the offspring being colorblind is 50%.