Biology 100 Test 2

All normal diploid cells in the human body have a complete set of DNA because diploid cells contain two complete sets of chromosomes, one from each parent. The DNA within these chromosomes carries all the genetic information necessary for the functioning and development of the human body. Therefore, it can be concluded that all normal diploid cells in the human body have a complete set of DNA.

A mutation refers to a change in the nucleotide sequence of DNA. This can occur due to various factors such as errors during DNA replication or exposure to certain environmental factors. Mutations can lead to genetic variations and can have significant impacts on an organism's traits and functions. Translation, non-disjunction, pteiotropy, and replication are not related to changes in the nucleotide sequence of DNA.

Egg and sperm cells are called gametes. Gametes are specialized reproductive cells that are involved in sexual reproduction. They are responsible for carrying the genetic information from the parents to the offspring. Clones refer to genetically identical organisms, hybrids are the offspring of two different species, somatic cells are non-reproductive cells, and stem cells are undifferentiated cells with the potential to develop into different cell types.

Autosomes are the non-sex chromosomes in an organism. These chromosomes are responsible for determining the traits and characteristics other than the sex of an individual. Unlike sex chromosomes, which determine the sex of an individual, autosomes are present in both males and females and carry genetic information related to various bodily functions and traits. Therefore, autosomes are the correct answer as they accurately represent the non-sex chromosomes.

The statement "An allele that is always fully expressed is referred to as recessive" is false. In genetics, an allele that is always fully expressed is referred to as dominant, not recessive. Recessive alleles are only expressed when an organism has two copies of that allele.

The centromere is the point where sister chromatids are attached together. During cell division, the sister chromatids separate and move to opposite poles of the cell, and the centromere plays a crucial role in ensuring the proper distribution of genetic material to the daughter cells. It acts as an attachment site for proteins that help in the movement and segregation of chromosomes. This process ensures that each daughter cell receives a complete set of chromosomes. Therefore, the centromere is not a molecule necessary to make copies of a gene, a structure where proteins are assembled together, or an enzyme that unzips a DNA molecule.

The given nucleotide sequence is ATAACCCGAT. To complete replication of a DNA molecule, the complementary strand needs to be formed. The complementary strand is formed by pairing adenine (A) with thymine (T) and cytosine (C) with guanine (G). Therefore, the correct sequence of nucleotides needed to complete replication would be TATTGGGCTA, where T pairs with A, A pairs with T, G pairs with C, and C pairs with G.

not-available-via-ai

The correct answer is that each parent could have contributed one recessive allele, resulting in type O blood. This explanation is based on the understanding of blood types and inheritance. In the case of the couple, the woman has blood type A and the man has blood type B. Both blood types are dominant, but the recessive allele for type O blood can be inherited from both parents. Therefore, it is possible for the baby to have type O blood even if both parents have different blood types.

A codon is a sequence of three nucleotides, which are the building blocks of DNA and RNA. These nucleotides determine the sequence of amino acids in a protein. Therefore, the correct pair of words to fill in the blanks is "nucleotides" and "amino acid".

The genetic information carried by a DNA molecule lies in the sequence of the different nucleotides along the length of the molecule. This is because the order of the nucleotides, which are adenine (A), thymine (T), cytosine (C), and guanine (G), determines the genetic code. The specific sequence of nucleotides forms genes, which are the instructions for building proteins. These proteins then carry out various functions in the cell, ultimately determining the traits and characteristics of an organism. Therefore, the sequence of nucleotides is crucial for transmitting genetic information.

At the beginning of mitosis, each chromosome of a eukaryotic cell consists of a pair of identical structures called sister chromatids. Sister chromatids are formed during DNA replication, where the DNA is duplicated and each copy remains attached to the other at a region called the centromere. These sister chromatids are held together until they separate during the later stages of mitosis, ensuring that each daughter cell receives an identical copy of the genetic material.

The given statement that "Cell division only occurs in cells that produce eggs and sperm" is false. Cell division is a fundamental process that occurs in all types of cells, not just in cells that produce eggs and sperm. Cell division is necessary for growth, repair, and maintenance of tissues in multicellular organisms. It involves the replication of DNA and the division of the cell into two daughter cells.

During Interphase of the Cell Cycle, the cell grows and a copy of DNA is made (DNA duplicates). However, the cell cytoplasm does not divide during Interphase.

During anaphase II of meiosis, the sister chromatids separate and move to opposite sides of the cell. This is the phase where the genetic material is divided equally between the daughter cells. In telophase I, the chromosomes decondense and the nuclear envelope reforms. Prophase II is the phase where the nuclear envelope breaks down and the spindle apparatus forms. Metaphase I is the phase where the homologous pairs of chromosomes align at the equator of the cell. Metaphase II is the phase where the individual chromosomes align at the equator of the cell.

Single trait, multiple gene inheritance occurs when many genes influence one characteristic. It produces phenotypes that tend to vary along a continuum. It works when the effects of many genes add together to produce a particular phenotype. It is also called polygenic inheritance. However, it does not tend to affect males much more than females.

A gene is not always expressed in the individual who has it. Gene expression is regulated by various factors such as environmental conditions, cellular signals, and the presence of specific regulatory proteins. Some genes may be expressed only under certain circumstances or in specific tissues, while others may be completely silent or inactive. Therefore, it is incorrect to assume that a gene is always expressed in the individual who possesses it.

When a cell is not dividing, the chromosomes are uncoiled into long, thin molecules of DNA and proteins called chromatin. Chromatin is the relaxed form of DNA that allows for gene expression and other cellular processes to occur. It is important for the regulation of gene activity and is responsible for the overall structure and organization of the genetic material within the cell nucleus.

Pairs of homologous chromosomes do not necessarily carry the same alleles. Homologous chromosomes are similar in size and carry genes for the same traits, but they can have different versions of those genes, known as alleles. This genetic variation allows for diversity and the possibility of different traits being expressed in offspring.

The correct answer is "Unspecialized, undifferentiated cells." Stem cells are a type of cells that are not yet specialized or differentiated into specific cell types. They have the potential to develop into different types of cells in the body and are important for various biological processes such as growth, development, and repair. Stem cells can be found in both plants and animals, and they are not specifically related to DNA replication or natural selection.

A human gamete, such as a sperm or an egg, contains only one sex chromosome. This is because during the process of meiosis, the cells that give rise to gametes undergo a special division where the number of chromosomes is halved. In the case of sex chromosomes, males have one X and one Y chromosome, while females have two X chromosomes. Therefore, a human gamete can either have an X chromosome (if it is an egg) or a Y chromosome (if it is a sperm), determining the sex of the offspring when it combines with another gamete during fertilization.

Color blindness is a sex-linked trait, meaning it is carried on the X chromosome. Since males have one X chromosome inherited from their mother, they can inherit color blindness if their mother carries the recessive color blindness allele. This is because males only need one copy of the recessive allele to express the trait. Therefore, if the mother carries the recessive color blindness allele, she can pass it on to her son, resulting in color blindness.

During prophase, the chromosomes condense and become visible. They also line up along the midline of the cell, forming a structure called the metaphase plate. This is the phase when the nuclear envelope breaks down and the spindle fibers start to form. Telophase is the phase when the chromosomes move to opposite ends of the cell, anaphase is the phase when the chromosomes separate and move to opposite poles, and metaphase is the phase when the chromosomes are fully aligned along the metaphase plate.

The pattern of color expression in the offspring, where all of them have pink flowers, suggests that neither the red nor the white allele is completely dominant over the other. In incomplete dominance, the heterozygous offspring exhibit a phenotype that is intermediate between the two homozygous phenotypes. In this case, the pink flowers in the offspring indicate that the red and white alleles are both expressed, resulting in a blend of the two colors. Therefore, incomplete dominance is the most likely explanation for this pattern of color expression.

Promoter sequences and terminator sequences are nucleotide sequences that either start or stop transcription at a specific location on the DNA molecule. They are not directly involved in the reading of these sequences by molecules of tRNA. Instead, tRNA molecules are responsible for carrying amino acids and matching them to the appropriate codons on the mRNA during translation. Therefore, the statement that proper reading of these sequences relies on molecules of tRNA is false.