Biology Unit 5

The outward appearance of a particular trait is called the ________.

phenotype

One gene controls the synthesis of one _____.

polypeptide

Genetics experiments on the breeding of plants or animals are based on the laws of _____.

probability

The chance that a certain event will occur is known as its _____.

probability

A cross involving purebred, red snapdragons and purebred, white snapdragons produce all pink offspring because both genes are present, neither being ________ over the other, resulting in the _______ of the trait.

1. Dominant 2. Blending

How have fossils contributed to our understanding of evolution?

1. Fossils can show the slow changes of macroevolution 2. A collection of fossils from the same strata can give us a picture of the organisms that could survive during that time period.

Macroevolution _____.

1. analyzes the history of life over time 2. refers to evolution above the species level 3. is based on direct observation

Chromosomes _____.

1. are rod shaped structures that contain DNA 2. are located in the nucleus 3. occur in numbers that are the same for all members of a certain species 4. are organized into karyotypes for scientists to analyze

Genes _____.

1. are specific nucleotide sequences 2. are located in a specific place on a chromosome 3. determine the traits of an organism

Fossils _____.

1. can show evolutionary relationships between organisms 2. suggest modern day organisms evolved over time 3. can be grouped together by age to form a fossil record

Genes are _____.

1. responsible for inherited traits 2. units of coded DNA 3. located in a specific place on a chromosome

You have a 12 sided cube that is numbered from 1 to 12. What is the probability of rolling a 5?

1/12

The probability of having the combination of one head and one tail when flipping two coins is _____.

1/2

What is the probability that a seed from a parent plant of genotype Rr will carry the r gene?

1/2

If one parent is heterozygous white (Ww) and the other is homozygous black (ww), give the phenotype and genotype ratios for this cross.

1/2 white, 1/2 black, 1:1

If you have two pennies, the probability of both coming up heads when flipped is _____.

1/4

Red-flowered snapdragons are crossed with white-flowered snapdragons, producing all pink snapdragons in the F1 generation. What would you expect if you crossed pink with pink?

1/4 red, 1/2 pink, 1/4 white,

Using the group of cards just described in this lesson, the probability of drawing a red five is

1/56

The second generation phenotypes resulting from the cross of true-breeding monohybrid pollination will display a ratio of _____.

3:1

A student analyzed ears of corn that demonstrated two traits in the F2 kernels, purple or white colors and smooth or wrinkled shapes. A tabulation of 135 individual kernels gave the following results: purple and smooth = 75 white and smooth = 28 purple and wrinkled = 24 white and wrinkled = 8 How many phenotypes are present?

4

A normal human karyotype has _____.

46 chromosomes

The phenotypic ratio for the F2 generation in a dihybrid cross will theoretically be _____.

9:3:3:1

Which of the following is an example of microevolution?

A population of birds with red feathers slowly changes to having blue feathers.

The genetic code is carried by the _____ molecule in most organisms.

DNA

Mutations in the genetic code can occur when _____.

DNA duplicates and an amino acid is changed

During the early stages of embryo development, dolphins have gill pouches. What does this mean?

Dolphins and fish share a distant, common ancestor.

The seeds collected from the first generation monohybrids are called _____.

F1

In sedimentary rock the oldest fossils would be expected to be found

In the bottom layer of rock

Over time, a tadpole changes into a frog. Has it evolved?

No, because its genes are still the same.

Both bats and honeybees have wings. Which of the following statements is true?

Since they do not come from a common ancestor, honeybee wings and bat wings are analogous structures.

While conducting experiments on pea plants, Mendel observed that the combination of traits in the offspring did not match up with the parents. How did Mendel explain this?

The Principle of Independent Assortment

Which of the following statements is true?

The more similar the embryonic development of two species, the more closely they are related.

Each hereditary trait corresponds to _____.

a sequence of nitrogen bases

The sugar and phosphate portion of the nucleotides are found _____ on the DNA twisted ladder.

as segments of the rails

Multiple alleles _____.

can interact to influence a trait, such as eye color

The evolution of the eohippus into the modern day horse is an example of _____.

character change

A red flower and a white flower produce pink offspring. What condition explains this phenomenon?

codominance

Comparative morphology _____.

compares the anatomy of organisms of different species

Heredity allows for ______.

consistency between generations

To determine if a particular plant is homozygous or heterozygous, you would have to test cross with a _____ to make the check.

homozygous recessive

Which of the following animals will have a forelimb most similar to a dolphin?

human

When the blending of traits occurs, it is referred to as the principle of _____.

incomplete dominance

Indicate the correct designation of the paired sex chromosomes.

male: XY female: XX

What can be expected for the recessive trait of monohybrids from the F2 generation?

none of the above all dominant traits all recessive traits 1/3 dominant traits 2/3 recessive traits

The probability of two independent events occurring together is the ________ of the probability of each event occurring separately.

product

A student analyzed ears of corn that demonstrated two traits in the F2 kernels, purple or white colors and smooth or wrinkled shapes. A tabulation of 135 individual kernels gave the following results: purple and smooth = 75 white and smooth = 28 purple and wrinkled = 24 white and wrinkled = 8 The ________ alleles are dominant.

purple and smooth

A student analyzed ears of corn that demonstrated two traits in the F2 kernels, purple or white colors and smooth or wrinkled shapes. A tabulation of 135 individual kernels gave the following results: purple and smooth = 75 white and smooth = 28 purple and wrinkled = 24 white and wrinkled = 8 What would be the only phenotype present in the F1 generation?

purple and smooth

During the process of _____, two rails or sides break apart and attract new nucleotide bases to form a new and complete strand.

replication

Mendel believed that during the formation of gametes, the pair of genes controlling a trait separate. He called this the principle of _____.

segregation

The nitrogen base pairs in the DNA molecule are adenine and ________ or cytosine and ________.

thymine and guanine

Why did Mendel prevent his plants from self-pollinating?

to control the crossing of the traits

During the process of _____, two rails or sides break apart and pair up with RNA nucleotides, assembling mRNA.

transcription

During the process of _____, mRNA decodes information from the original DNA master plan to build proteins in the ribosomes.

translation

Evolution _____.

is a slow, gradual change over time

The steps of the DNA ladder are made of _____.

paired nitrogen bases

Meiosis is associated with the _____.

1. haploid number of chromosomes 2. gamete cells

Factors that can increase mutation rates are _____.

1. high temperatures 2. food additives 3. UV rays

What characteristics do mutations have?

1. occasionally beneficial 2. omission of information 3. mistakes in copying

Each trait of a plant is determined by _____.

a pair of genes

The genotype represents _____.

a paired combination of genes

Environmental factors ________ affect the coding of genes.

can

Whales have vestigial legs. This suggests they _____.

descended from land animals

A monohybrid cross is made between plants that _____.

differ in only one trait

Recessive genes will always be masked by dominant genes. This is Mendel's principle of _______.

dominance

The characteristic that results from a monohybrid cross is the _____ trait.

dominant

Traits that are sex-linked are carried on _____.

either the X or Y chromosome

A gene cannot react chemically and form a trait without the proper _____.

enzyme

Which of the following is an example of haploid cells?

gametes

In a dihybrid cross, the F2 will have nine genotypes, but only four phenotypes because the _________ genes cause the _________ traits to mask the _________ traits.

heterozygous dominant recessive

Ribosomal RNA is produced by _____.

nucleoli

rRNA _____.

transports amino acids from cytoplasm to ribosomes