Correct Answer: D. Rabbit

Explanation

A primary consumer is a herbivore that consumes only producers or autotrophs. For this question, rabbits only eat plants and so they would be considered the primary consumers. Grass and other organisms that can manufacture their own food are classified as primary producers. Snakes and hawks hunt other animals (such as rabbits) for food, so they must be at least secondary consumers. Fungi break down dead organisms for nutrition and are thus classified as decomposers.

Correct Answer: D. autotrophs

Correct Answer: B. the pectoral fin

Correct Answer: A. Primary Consumers

Correct Answer: A) Produced by many genes

Explanation

This question is asking about the characteristics of continuous variation. Continuous variation is when there is a wide range of possible values for a trait, rather than just a few discrete options. The question asks which of the following is not a characteristic of continuous variation. Option A says that continuous variation is produced by many genes, but this is actually a characteristic of continuous variation. This means that many different genes can influence the trait, leading to a wide range of possible values. Option B says that continuous variation is influenced by the environment, and this is a true characteristic of continuous variation. The environment can play a role in determining the trait, such as with height or weight. Option C says that continuous variation occurs in a normal distribution curve, and this is also true. A normal distribution curve is a bell curve shape that shows the range of values for a trait in a population. Option D says that most of the organisms in the population fall at the tail ends of the range, but this is not a characteristic of continuous variation. Instead, it is a characteristic of bimodal variation, where there are two distinct groups of values for a trait. Therefore, the correct answer is option A, which is Produced by many genes. This is not a characteristic of bimodal variation, but it is a characteristic of continuous variation.

Correct Answer: D. Directional selection

Explanation

The question describes a particular trait

Correct Answer: D. All blue

Explanation

The phenotypic ratio is the ratio of one phenotype to another (phenotype is the trait expressed, in this case color, while genotype is the allele combination (BB, bb, Bb, or bB) that produces that phenotype. The capital letters BB signify that the blue allele (B) is dominant to the white allele (b). As such, the only genotype that will produce white plants is bb. All other combinations (BB, Bb, bB) will produce a blue plant. If you cross a homozygous (both dominant or both recessive) dominant plant with a homozygous recessive plant, the dominant allele will be present in all of the offspring, as every possible allele the blue plant could contribute will be dominant to every possible allele the white plant could contribute, making all of the offspring blue.

Correct Answer: A. ready for mating

Correct Answer: C. mistletoe growing on an orange tree

Correct Answer: C. Plant cells contain chloroplasts for photosynthesis, while animal cells do not