Bio 2 - Warm-up Quiz #11

Extinction refers to the complete and permanent disappearance of a species from Earth. It occurs when a species cannot adapt to changes in its environment or faces threats such as habitat loss, climate change, or human activities. Extinction can have significant ecological and environmental impacts, disrupting ecosystems and leading to the loss of biodiversity. Coevolution, equilibrium, and natural selection are all important concepts in biology, but they do not specifically refer to the total permanent disappearance of a species.

Gametes must be haploid because two gametes will unite during fertilization to create a diploid cell. If the gametes were already diploid, the resulting zygote would have double the number of chromosomes, leading to an abnormal number of chromosomes in the offspring. Therefore, gametes need to be haploid to ensure that the resulting zygote has the correct number of chromosomes.

A population refers to all the individuals of a species that inhabit a specific area. It represents a group of organisms of the same species that interact with one another and share a common gene pool. This term is commonly used in ecological and biological studies to analyze the dynamics, distribution, and characteristics of a specific species within a given geographical region.

A substrate is the term for a molecule that combines with enzymes, undergoes a chemical reaction, and changes into new substances. Enzymes are biological catalysts that facilitate chemical reactions in the body by binding to specific substrates and converting them into different products. The substrate is the molecule that is acted upon by the enzyme and is transformed during the reaction. Therefore, substrate is the correct answer in this context.

DNA is composed of nucleotide subunits, each of which contains a phosphate group. The phosphate group is an essential component of the nucleotide structure and is responsible for linking the nucleotides together to form the DNA molecule. It plays a crucial role in the stability and integrity of the DNA structure. The other options, such as ribose molecule, uracil base, and protein, are not present in DNA or are not fundamental components of the nucleotide structure.

Aerobic respiration produces the greatest amount of ATP. This process occurs in the presence of oxygen and involves the breakdown of glucose to produce energy. Through a series of chemical reactions, aerobic respiration generates a large amount of ATP, which is the primary source of energy for cells. In comparison, fermentation and anaerobic respiration produce a smaller amount of ATP, while photosynthesis is a process that produces glucose rather than ATP.

The ratio of 0 in 4 indicates that none of the offspring from the cross shown will be homozygous recessive for the trait of tallness. This means that all of the offspring will either be heterozygous for tallness or homozygous dominant for tallness.

In the ladder-like model of DNA, the vertical "backbones" consist of sugar and phosphate groups. These sugar and phosphate groups alternate to form the backbone of the DNA molecule. The nitrogen bases are attached to the sugar groups and form the rungs of the DNA ladder. ATP, although important for cellular energy, is not a component of the DNA molecule. Nucleotides, on the other hand, are the building blocks of DNA and consist of a sugar, a phosphate group, and a nitrogen base. However, in the given question, the specific components of the vertical backbones are being asked, which are the sugar and phosphate groups.

During Prophase I of meiosis, certain gene segments of the homologous pairs of chromosomes "cross over" and exchange genetic information. This is a crucial step in meiosis where genetic recombination occurs, leading to genetic diversity. Prophase I is characterized by the condensation of chromosomes, the pairing of homologous chromosomes, and the formation of the synaptonemal complex. This complex facilitates the physical exchange of genetic material between the homologous chromosomes, resulting in the crossing over of gene segments.

When a heterozygous black-fur rabbit mates with a homozygous recessive rabbit, there is a 50% chance that the offspring will inherit the recessive white-fur trait. This is because the heterozygous black-fur rabbit carries one dominant black-fur allele and one recessive white-fur allele, while the homozygous recessive rabbit carries two recessive white-fur alleles. In this scenario, there are two possible genotypes for the offspring: one with a dominant black-fur allele and a recessive white-fur allele, and one with two recessive white-fur alleles. Therefore, the probability of producing white-fur offspring is 1/2 or 50%.

Moving the light source closer to the beaker is most likely to increase the volume of oxygen gas that accumulates in the top of the tube. This is because the aquatic plant undergoes photosynthesis, a process that requires light energy to convert carbon dioxide and water into glucose and oxygen. By moving the light source closer to the beaker, the plant receives more light energy, which increases the rate of photosynthesis. As a result, more oxygen gas is produced and accumulates in the top of the tube.

Carol made a mistake by concluding that the phenotypic ratio of the monohybrid cross is 2:1:1. The correct ratio should be 3:1. This is because both male and female rats have the genotype Bb, which means they have one dominant allele (B) and one recessive allele (b). When these rats are crossed, the possible genotypes of the offspring are BB, Bb, and bb. The dominant phenotype is expressed when the genotype is BB or Bb, while the recessive phenotype is expressed when the genotype is bb. Therefore, the phenotypic ratio should be 3 dominant (BB or Bb) to 1 recessive (bb).