Question 1

Which of the following best describes a characteristic of a good scientific hypothesis?

Accepted Answer

It is a statement that can be tested and potentially falsified through experimentation.

Question 2

In an experiment testing the effect of fertilizer on plant growth, which variable is the independent variable?

Accepted Answer

The amount of fertilizer applied to the plants.

Question 3

How does genetic diversity contribute to overall biodiversity in an ecosystem?

Accepted Answer

It increases the variety of traits within a species, allowing populations to adapt to changing environments.

Question 4

Which of the following best explains the greenhouse effect and its role in global warming?

Accepted Answer

Greenhouse gases trap heat in the Earth's atmosphere, leading to an increase in global temperatures.

Question 5

During meiosis I in a cell with $$2n = 2$$, how are homologous chromosomes and sister chromatids arranged?

Accepted Answer

Homologous chromosomes are paired together, each consisting of two sister chromatids.

Question 6

The experiment with C. elegans grown with or without pathogens supports the changing environment hypothesis for sexual reproduction because:

Accepted Answer

Sexually reproducing populations adapt better to new pathogens due to increased genetic variation.

Question 7

Why is meiosis necessary for sexual reproduction in most organisms?

Accepted Answer

Meiosis reduces the chromosome number by half, allowing gametes to fuse and restore the diploid state.

Question 8

In peas, tall ($$T) is $$dominant over short ($$t). If a $$heterozygous tall plant ($$Tt) is $$crossed with a homozygous short plant ($$tt$$), what is the expected phenotypic ratio of their offspring?

Accepted Answer

1 tall : 1 short

Question 9

In rabbits, black fur ($$B) is $$dominant over white fur ($$b). If $$two heterozygous black-furred rabbits ($$Bb) $$are crossed, what is the probability of them having a white-furred offspring?

Accepted Answer

$$\frac{1}{4}$$

Question 10

In fruit flies, red eyes ($$R) $$are dominant over white eyes ($$r). If a $$heterozygous red-eyed fly ($$Rr) is $$crossed with a white-eyed fly ($$rr$$), what is the expected genotype ratio of their offspring?

Accepted Answer

1 $$Rr$$ : 1 $$rr$$

Question 11

In horses, brown coat color ($$B) is $$dominant over chestnut ($$b). If $$two heterozygous brown-coated horses ($$Bb) $$are crossed, what is the expected phenotypic ratio of their foals?

Accepted Answer

3 brown : 1 chestnut

Question 12

In guinea pigs, genes for fur color and fur length segregate independently. If a heterozygous black short-furred guinea pig ($$BbLl) is $$crossed with a brown long-furred guinea pig ($$bbll$$), which of the following is a possible phenotype among their offspring?

Accepted Answer

Black long-furred

Question 13

In fruit flies, genes for wing shape ($$W/w) $$and eye color ($$E/e) $$are linked on the same chromosome. If a heterozygous winged, red-eyed fly ($$WwEe) is $$crossed with a homozygous wingless, white-eyed fly ($$wwee$$), what is the expected phenotype ratio of their offspring (assuming no crossing over)?

Accepted Answer

1 winged, red-eyed : 1 wingless, white-eyed

Question 14

Which scenario best illustrates how multiple alleles can interact to produce a range of phenotypes, differing from simple Mendelian inheritance?

Accepted Answer

Human blood type, where alleles $$I^A$$, $$I^B$$, and $$i$$ combine to produce types A, B, AB, and O.

Question 15

How does the phenotypic ratio in a cross exhibiting incomplete dominance differ from one showing complete dominance?

Accepted Answer

Incomplete dominance produces a 1:2:1 ratio of phenotypes, while complete dominance produces a 3:1 ratio.

Question 16

Why might genetically identical plants exhibit different phenotypes when grown in different environments?

Accepted Answer

Environmental factors such as light, water, and nutrients can influence gene expression.

Question 17

Which of the following best distinguishes pleiotropy from gene interaction?

Accepted Answer

Pleiotropy occurs when one gene affects multiple traits, while gene interaction involves multiple genes influencing a single trait.

Question 18

Traits governed by quantitative inheritance, such as human height, often show a bell curve distribution in a population because:

Accepted Answer

Multiple genes contribute additively to the trait, resulting in continuous variation.

General Biology Exam 1 Review: Genetics, Experimental Design, and Biodiversity

Study Guide - Practice Questions

Study Guide - Flashcards