Structure
Name the nitrogenous bases present in DNA
A,C,T,G
What is stem cells?
What are 2 major types of stem cells?
Stem cells are unspecialised cells.
types
1. Embryonic stem cells
2. Adult stem cells
If a DNA sample contains 30% adenine (A), what percentage of thymine (T) would you expect to find in the same sample?
30%
20%
40%
60%
30%
What are the three parts of a nucleotide? Select ALL that apply
What are the three parts of a nucleotide? Select ALL that apply
Chromosome
RNA
Gene
Sugar
Nitrogen Base
Phosphate
4,5,6
In a DNA molecule, what connects the phosphate group to the nitrogenous base?
A. A hydrogen bond
B. The sugar, deoxyribose
C. A lipid chain
D. An amino acid
B. The sugar, deoxyribose
Which of the following holds the two strands of a DNA double helix together?
A. Phosphate groups
B. Hydrogen bonds
C. Amino acids
D. Lipids
B. Hydrogen bonds
What is one way environmental factors can influence cell differentiation?
A. By changing the number of chromosomes in the cell
B. By determining which genes are expressed in certain cells
C. By increasing the size of the cell’s nucleus
D. By changing the amount of cytoplasm in a cell
B. By determining which genes are expressed in certain cells
In DNA, which nitrogenous base always pairs with adenine?
A. Cytosine
B. Uracil
C. Guanine
D. Thymine
D. Thymine
What is cancer?
A group of diseases characterized by uncontrolled cell growth.
A type of infectious disease caused by bacteria.
A nutritional deficiency that leads to weakened bones.
A genetic disorder that affects the production of red blood cells.
A group of diseases characterized by uncontrolled cell growth.
If one strand of DNA has the sequence GGTACG, what is the sequence of its complementary strand?
CCTGCA
CCAUGC
CGATGC
CCATGC
CCATGC
what are the major differences between RNA and DNA?
RNA - Single strand, Ribose sugar, Uracil
DNA -double strand, Deoxy ribose sugar, thymine
As the embryo develops, cells begin to specialize into different types, such as muscle cells,
nerve cells, and blood cells. This process of becoming specialized is called _________________.
differentiation
Humans have thousands of genes that combine in different
ways to help create unique individuals. Where is the genetic
code primarily located?
A. Ribose sugar in RNA
B. Phosphates in DNA
C. Nucleotides in DNA
D. Exons in RNA
C. Nucleotides in DNA
Apoptosis is the process by which cells are programmed to die. What might happen if a cell does not undergo apoptosis as it should?
A. The cell will replicate uncontrollably, potentially forming a tumor.
B. The cell will stop dividing entirely, slowing tissue growth.
C. The cell will lose its ability to produce proteins.
D. The cell will divide at a slower rate, preventing cancer.
A. The cell will replicate uncontrollably, potentially forming a tumor.
The European common frog (Rana temporaria) can change its skin color based on its surroundings, such as blending into a dark substrate or light sand. What does this demonstrate about environmental influence on traits?
A. The frog's skin color genes mutate based on the environment.
B. The frog's skin color genes are permanently altered by environmental changes.
C.Environmental factors can influence the expression of genes related to pigmentation.
D. Other amphibian species are not affected by their surroundings
C.Environmental factors can influence the expression of genes related to pigmentation.
In Texas Longhorn cattle, coat coloration is an inherited trait. What is the genetic basis of
coat-color variation in Texas Longhorn cattle?
A. Differences in the nucleotide sequences of genes
B. Differences in the number of chromosomes in cells
C. Differences in the diets of individual cattle
D. Differences in the environmental conditions of different geographic areas
A.Differences in the nucleotide sequences of genes
Scientists have theorized that the DNA molecule originated from a molecule whose building block is the same as that of DNA. This molecule is thought to be:
A. RNA
B. Protein
C. Lipid
D. Carbohydrate
A. RNA
Which of the following BEST explains how a mutation in cell cycle checkpoints can lead to cancer?
A. It allows cells to grow uncontrollably by skipping necessary rest phases.
B. It forces cells to produce extra energy and proteins.
C. It prevents normal cell growth, causing tissues to shrink.
D. It leads to the cell’s inability to use oxygen properly.
A. It allows cells to grow uncontrollably by skipping necessary rest phases.
Cells typically respond to DNA damage in three ways: by ceasing to grow and divide until the
damage is repaired, by permanently ceasing to grow and divide, or by dying. In 2010 a group of
scientists reported that a certain kind of immune reaction can cause DNA damage that leads to a
fourth response. DNA damage can turn off genes involved in cell-signaling pathways. Turning off
these genes can cause less-mature cells to divide too rapidly, often leading to the development of________________________________________
Tumors
David is studying a scientific debate about the origins of DNA. He reads that one theory, the
Co-Evolution Hypothesis, suggests that both DNA and RNA may have formed around the same
time. This contrasts with other theories that say RNA came first. David wants to understand why
scientists consider both theories when studying the origin of life.
What is the main difference between the RNA-World Hypothesis and the Co-Evolution Hypothesis?
A. The RNA-World Hypothesis suggests that RNA and DNA evolved together, while the
Co-Evolution Hypothesis suggests that DNA evolved first.
B. The RNA-World Hypothesis suggests that RNA came first, while the Co-Evolution
Hypothesis proposes that DNA and RNA evolved simultaneously.
C. The RNA-World Hypothesis suggests that DNA came before RNA, while the Co-Evolution
Hypothesis claims RNA came first.
B. The RNA-World Hypothesis suggests that RNA came first, while the Co-Evolution
The Arctic fox changes its fur color from brown in summer to white in winter, allowing it to blend into its snowy environment. What does this demonstrate about environmental influence on traits?
A. Seasonal changes cause genetic mutations that alter fur color.
B. Environmental factors, such as seasonal temperature and snow cover, can influence gene expression related to fur color.
C. The fur color genes are permanently switched off in summer.
D. Other fox species do not exhibit changes in fur color based on their environment.
B. Environmental factors, such as seasonal temperature and snow cover, can influence gene expression related to fur color.
How many nucleotides are there in the DNA? Explain the importance of the nucleotide sequence to an organism.
There are four nucleotides in the DNA. The nucleotide sequence is important to an organism
because it provides/carries the instructions for the traits of an organism.
In the structure of DNA, the phosphate backbone plays a crucial role in maintaining the integrity of the double helix. Which of the following statements correctly describes the phosphate backbone?
It is located only on one side of the DNA strand.
It consists of nitrogenous bases that pair with each other.
It is made up of alternating sugar and phosphate molecules.
It forms the rungs of the DNA ladder.
3. It is made up of alternating sugar and phosphate molecules
The instructions for building proteins are found in DNA. Where is the genetic code primarily located?
A. In the phosphate groups of the DNA strand
B. In the sequence of nucleotides along the DNA strand
C. In the ribose sugars found in RNA
D. In the lipids found in the cell membrane
B. In the sequence of nucleotides along the DNA strand
Paleobiologist Dr. Sarah Nkrumah discovers microscopic structures in 3.5 billion-year-old rocks that appear to be fossilized cell-like entities. Chemical analysis suggests the presence of organic compounds, but no clear evidence of DNA. This finding most directly challenges which assumption about the origin of DNA?
DNA was the first genetic material
DNA originated in hydrothermal vents
DNA formed through chemical evolution
DNA requires oxygen for its formation of primitive cell membranes
DNA was the first genetic material