Unit 2- Extra Review

During the 1800s, Gregor Mendel conducted experiments with pea plants. His work showed that organisms inherit traits from their parents and that some traits are dominant over others. Mendel's work was ignored for a long time because scientists could not explain how traits were carried from one generation to the next. What discovery provided scientists with a way to explain Mendel's work?

• ribonucleic acids

• cells

• atoms

• Punnett Squares

In human beings, having unattached earlobes (A) is a dominant characteristic over attached earlobes (a). The Punnett square shows the genetic distribution of two parents, one with attached earlobes and one with unattached earlobes.

What is the chance that their offspring will have unattached earlobes?

• 25%

• 50%

• 75%

• 100%

A homozygous brown mouse mates with a heterozygous brown mouse. The allele for brown fur (B) is dominant over the allele for tan fur (b). What percentage of the offspring will most likely have brown fur?

• 25%

• 50%

• 75%

• 100%

How does an offspring produced by asexual reproduction compare to the parent organism?

• Its genetic information is completely different from the parent organism.

• It contains 1/4 of the genetic information from the parent organism.

• It contains 1/3 of the genetic information from the parent organism.

• All of its genetic information is the same as the parent organism.

Which organism has the highest reproductive potential?

• bacteria

• elephant

• human

• sea turtle

A green-seeded pea plant and a yellow-seeded pea plant have offspring with all yellow seeds. What is the most likely reason?

• The offspring only inherited genes from the yellow-seeded parent.

• The offspring inherited more genes from the yellow-seeded parent.

• The genes from the yellow-seeded parent were dominant.

• The genes from the yellow-seeded parent were recessive.

How many chromosomes are shown in a normal human karyotype?

• 2

• 23

• 44

• 46

What determines gender in humans?

• only the X chromosome

• the X and Y chromosomes

• chromosome 21

• epistasis

The picture shows an animal cell with structures X and Y labeled.

Which of the following best explains the relationship between structures X and Y?

• X, chromosomes, are located inside Y, the nucleus, and these structures store genetic material for the cell.

• X, ribosomes, are located inside Y, the nucleus, and these structures provide protection for the cell.

• X, nuclei, are located inside Y, chromosomes, and these structures provide energy for the cell.

• X, chromosomes, are located inside Y, DNA, and these structures store proteins for the cell.

Some horses are bred for speed, while other horses are bred for pulling heavy loads. What is the main influence on whether a horse will become a racehorse or a farm horse?

• the diet and care it receives

• the training it receives after birth

• the environment it is raised in

• the genes it inherits from its parents